tag:theconversation.com,2011:/us/topics/charles-darwin-9890/articlesCharles Darwin – The Conversation2023-10-13T14:59:57Ztag:theconversation.com,2011:article/2120762023-10-13T14:59:57Z2023-10-13T14:59:57ZScientists can’t agree on when the first animals evolved – our research hopes to end the debate<figure><img src="https://images.theconversation.com/files/552051/original/file-20231004-23-9ypi1g.jpg?ixlib=rb-1.1.0&rect=7%2C0%2C5104%2C2874&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-beautiful-paleontologist-cleaning-tyrannosaurus-dinosaur-1955215525">Gorodenkoff/Shutterstock</a></span></figcaption></figure><p>There are estimated to be nearly <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001127">8 million species of animals</a> living today, making up the majority of Earth’s documented biodiversity and inhabiting almost all of its environments. However, for most of Earth’s history animals were completely absent. </p>
<p>The date of the first animals marks a shift in the history of life on Earth. Of course, as animals ourselves, it’s also the story of our origins. Without animals, our planet would have been a very different world. </p>
<p>The question of exactly when animals first evolved has puzzled scientists for centuries. <a href="https://www.pnas.org/doi/full/10.1073/pnas.97.13.6947">Even Charles Darwin</a> was stumped. He predicted a long history of evolution from simple single celled organisms to complex animals. However, the oldest animal fossils Darwin knew of, from around 500 million years ago, were large enough to be visible to the naked eye and often had shells and skeletons. </p>
<p><a href="https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(23)00137-4">My team’s study</a> hopes to help settle the debate through a new approach to the question. </p>
<h2>Why animal evolution is controversial</h2>
<p>Scientists used to think animal fossils appeared suddenly in a time period around 500 million years ago called the <a href="https://linkinghub.elsevier.com/retrieve/pii/S0960982215004984">Cambrian Explosion</a>, so named because the fossil record seems to show a sudden boom in complex life at this time. We know the first animals evolved in the oceans, and with their abilities to move and burrow, they fundamentally altered the <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gbi.12267">Earth’s carbon cycle</a>.</p>
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<p>However, since Darwin, palaeontologists have discovered thousands more fossils, some of them more ancient than the Cambrian Explosion. Impressions of strange-looking organisms, called the <a href="https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(08)00306-6">Ediacara Biota</a>, were discovered in the 1950s in rocks and have been dated to around 574–539 million years ago (the <a href="https://www.nature.com/articles/s41559-019-0821-6">Ediacaran Period</a>). Some of the Ediacara Biota fossils represent the <a href="https://www.science.org/doi/10.1126/sciadv.abe0291">oldest animal fossils known</a>.</p>
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<a href="https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Hollows left by _Dickinsonia_ specimens - looks like an oval-shaped fern." src="https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544775/original/file-20230825-13578-gfmxl9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption"><em>Dickinsonia</em> are species in the Ediacara Biota.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hollows-left-by-dickinsonia-specimens-seafloor-1465917044">Alizada Studios/Shutterstock</a></span>
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<p>Yet these recent advances have taken the animal fossil record back only so far. Reports of older and more simple animal-like fossils have been published. For example, <a href="https://www.nature.com/articles/s41586-021-03773-z">sponge-like fossils</a> from the Mackenzie Mountains, Canada are around 800 million years old. But these older fossils <a href="https://onlinelibrary.wiley.com/doi/10.1111/sed.13059">cannot yet be conclusively proven to be animals</a>. They could be algae or perhaps not even fossils at all.</p>
<p>Also, the presence of fossils doesn’t necessarily confirm the date for the evolutionary origin of animals. Only a fraction of life has ever been fossilised meaning the fossil record is <a href="https://royalsocietypublishing.org/doi/full/10.1098/rstb.2015.0130">full of gaps</a>. </p>
<p>With no definitive first animal fossils, palaeontologists have turned to molecular biology, using genetics to trace ancestry. This technique, called the <a href="https://www.nature.com/articles/nrg.2015.8">molecular clock</a>, works by sampling the genetics of modern animals and comparing their DNA. The differences in DNA between species shows how much evolution has happened. </p>
<p>Although molecular clocks can only provide estimates for the timing of animal origins, <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(15)01177-X?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS096098221501177X%3Fshowall%3Dtrue">most converge on around 800–700 million years ago</a>, long before the Ediacaran extent of the animal fossil record.</p>
<p>This gives us two estimates for animal origins, more than 200 million years apart. On the one hand fossils extend to 574 million years ago, while on the other, molecular clocks suggest animals could be as old as 800 million years.</p>
<h2>Turning back the clock</h2>
<p>In our <a href="https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(23)00137-4">recent paper</a>, my colleagues and I suggest a new way to estimate the timing of animal origins. Instead of documenting the oldest animal fossils, we first considered which kind of rocks could preserve those animals.</p>
<p>An animal’s body type determines what kind of rock can fossilise it. Many animals have shells and skeletons that can be preserved in most types of <a href="https://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3458.html">sedimentary rocks</a> – such as sandstone – that start as sediments in rivers. However, the <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/brv.12614">first animals did not have shells or skeletons</a>. Animals evolved these structures at a later time. </p>
<p>Studying deposits such as the <a href="https://burgess-shale.rom.on.ca/">Burgess Shale</a> fossil bed in Canada, which is around 508 million years old, showed my team that fossils of animals lacking shells or skeletons, such as worms, are often <a href="https://pubs.geoscienceworld.org/gsa/geology/article-abstract/46/4/347/528312/A-mineralogical-signature-for-Burgess-Shale-type">confined to rocks that are rich in clay minerals</a>. Clays have <a href="https://pubs.geoscienceworld.org/gsa/geology/article-abstract/44/10/867/195089/Experimental-evidence-that-clay-inhibits-bacterial?redirectedFrom=fulltext">antibacterial properties</a> and can <a href="https://pubs.geoscienceworld.org/gsa/geology/article-abstract/49/4/355/592775/Early-formation-and-taphonomic-significance-of?redirectedFrom=fulltext">stop the decay</a> of animal soft tissues.</p>
<p>We tested rocks from geological eras older than the Ediaracan period (635 million years ago) to work out which ones had the clay-rich composition necessary to fossilise the first animals. Rare rocks around <a href="https://royalsocietypublishing.org/doi/10.1098/rsfs.2020.0011">790 million years old from Canada, Norway and Russia</a> have the necessary clay-rich properties.</p>
<p>Although these rocks could preserve the first animals, none of them do. This suggests that animal fossils are absent at this point in time, not because they couldn’t be preserved but perhaps because they weren’t there – that animals hadn’t evolved yet.</p>
<p>Palaeontologists now need to search more geological sites across the planet to confirm the youngest clay-rich rocks that could have preserved the first animals, but where animal fossils are absent. This will help us to home in on the true timing of animal origins.</p><img src="https://counter.theconversation.com/content/212076/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ross Anderson receives funding from the Royal Society. </span></em></p>Charles Darwin knew the evidence from fossils contradicted evolution. Researchers are still trying to work out the problem today.Ross Anderson, Research Fellow in Palaeobiology, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2132712023-09-13T14:00:06Z2023-09-13T14:00:06ZFlowering plants survived the dinosaur-killing asteroid – and may outlive us<figure><img src="https://images.theconversation.com/files/547777/original/file-20230912-15-mm7cp3.jpg?ixlib=rb-1.1.0&rect=53%2C44%2C5937%2C3943&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pink-rose-flower-pastel-ink-creative-1336421165">Zamurovic Brothers/Shutterstock</a></span></figcaption></figure><p>If you looked up 66 million years ago you might have seen, for a split second, a bright light as a mountain-sized asteroid burned through the atmosphere and smashed into Earth. <a href="https://www.nature.com/articles/s41586-022-04446-1">It was springtime</a> and the literal end of an era, the <a href="https://www.usgs.gov/youth-and-education-in-science/mesozoic">Mesozoic</a>. </p>
<p>If you somehow survived the initial impact, you would have witnessed the devastation that followed. Raging firestorms, megatsunamis, and <a href="https://pubmed.ncbi.nlm.nih.gov/11539442/">a nuclear winter</a> lasting months to years. The 180-million-year reign of non-avian dinosaurs was over in the blink of an eye, as well as at least <a href="https://www.science.org/doi/abs/10.1126/science.215.4539.1501?casa_token=DrtWs804WZsAAAAA:4SB3Ih2f1Ffnvilw9c8jxUViVd3IvyUVQRQ9PHOIezMQ7O5K9fR3a_nTWZWVKDJ94uKgsCBUfMH7Kg">75% of the species</a> who shared the planet with them. </p>
<p>Following this event, known as the <a href="https://www.britannica.com/science/K-T-extinction">Cretaceous-Paleogene mass extinction</a> (K-Pg), a new dawn emerged for Earth. Ecosystems bounced back, but the life inhabiting them was different.</p>
<p>Many iconic pre-K-Pg species can only be seen in a museum. The formidable <em>Tyrannosaurus rex</em>, the <em>Velociraptor</em>, and the winged dragons of the <em>Quetzalcoatlus</em> genus could not survive the asteroid and are confined to deep history. But if you take a walk outside and smell the roses, you will be in the presence of ancient lineages that blossomed in the ashes of K-Pg. </p>
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<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em>
<em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
<hr>
<p>Although the living species of roses are not the same ones that shared Earth with <em>Tyrannosaurus rex</em>, their lineage (family Rosaceae) <a href="https://www.nature.com/articles/s41467-020-17116-5">originated tens of millions of years</a> before the asteroid struck.</p>
<p>And the roses are an not unusual angiosperm (flowering plant) lineage in this regard. Fossils and genetic analysis suggest that the <a href="https://www.nature.com/articles/s41559-020-1241-3">vast majority of angiosperm families</a> originated before the asteroid. </p>
<p>Ancestors of the ornamental orchid, magnolia and passionflower families, grass and potato families, the medicinal daisy family, and the herbal mint family all shared Earth with the dinosaurs. In fact, the explosive evolution of angiosperms into the roughly 290,000 species today may have been facilitated by K-Pg. </p>
<p>Angiosperms seemed to have taken advantage of the fresh start, similar to the early members of our own lineage, <a href="https://www.cell.com/current-biology/pdf/S0960-9822(23)00767-4.pdf">the mammals</a>. </p>
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<img alt="Purple flower growing out of a crack in the pavement" src="https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547779/original/file-20230912-35629-s73lh2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Flowers are surprisingly resilient.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/purple-flower-growing-on-crack-street-776381272">PopTika/Shutterstock</a></span>
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<p>However, it’s not clear how they did it. Angiosperms, so fragile compared with dinosaurs, cannot fly or run to escape harsh conditions. They rely on sunlight for their existence, which was blotted out. </p>
<h2>What do we know?</h2>
<p>Fossils in different regions tell different versions of events. It is clear there was high angiosperm turnover (species loss and resurgence) <a href="https://www.science.org/doi/full/10.1126/science.abf1969?casa_token=s5xuTGC7SpAAAAAA%3AJHgkvkmunfwRZLpwfcoumaus-20jehSJ4vDnlJa8LRzFqco_pveiJVbdvHm1h2P3SXvHckDRN5ERuw">in the Amazon</a> when the asteroid hit, and a decline in plant-eating insects <a href="https://www.pnas.org/doi/10.1073/pnas.042492999#:%7E:text=The%20most%20specialized%20associations%2C%20which,associations%20regained%20their%20Cretaceous%20abundances">in North America</a> which suggests a loss of food plants. But other regions, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0034666723001021?via%3Dihub">such as Patagonia</a>, show no pattern. </p>
<p>A study in 2015 analysing angiosperm fossils of 257 <a href="https://www.britannica.com/science/genus-taxon">genera</a> (families typically contain multiple genera) found K-Pg had <a href="https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.13247">little effect</a> on extinction rates. But this result is difficult to generalise across the <a href="https://academic.oup.com/sysbio/article/71/2/301/6275244">13,000 angiosperm genera</a>. </p>
<p>My colleague Santiago Ramírez-Barahona, from the Universidad Nacional Autónoma de México, and I took a new approach to solving this confusion in a study we <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2023.0314">recently published</a> in Biology Letters. We analysed large angiosperm family trees, which previous work mapped from mutations in DNA sequences from 33,000-73,000 species. </p>
<p>This way of tree-thinking has laid the groundwork for major insights about the evolution of life, since the first family tree was scribbled by Charles Darwin. </p>
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<a href="https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scribble of a diagram with handwritten notes to the sides and underneath" src="https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=978&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=978&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=978&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1229&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1229&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547814/original/file-20230912-25-6n0182.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1229&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Charles Darwin’s first diagram of an evolutionary tree from 1837.</span>
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<p>Although the family trees we analysed did not include extinct species, their shape contains clues about how extinction rates changed through time, through the way the branching rate ebbs and flows. </p>
<p>The extinction rate of a lineage, in this case angiosperms, can be estimated using mathematical models. The one we used compared ancestor age with estimates for how many species should be appearing in a family tree according to what we know about the evolution process. </p>
<p>It also compared the number of species in a family tree with estimates of how long it takes for a new species to evolve. This gives us a net diversification rate - how fast new species are appearing, adjusted for the number of species that have disappeared from the lineage. </p>
<p>The model generates time bands, such as a million years, to show how extinction rate varies through time. And the model allowed us to identify time periods that had high extinction rates. It can also suggest times in which major shifts in species creation and diversification have occurred as well as when there may have been a mass extinction event. It shows how well the DNA evidence supports these findings too. </p>
<p>We found that extinction rates seem to have been remarkably constant over the last 140-240 million years. This finding highlights how resilient angiosperms have been over hundreds of millions of years. </p>
<p>We cannot ignore the <a href="https://www.cambridge.org/core/journals/cambridge-prisms-extinction/article/endcretaceous-plant-extinction-heterogeneity-ecosystem-transformation-and-insights-for-the-future/D74EBD512E4261E4C28BB7AF024E80B9">fossil evidence</a> showing that many angiosperm species did disappear around K-Pg, with some locations hit harder than others. But, as our study seems to confirm, the lineages (families and orders) to which species belonged carried on undisturbed, creating life on Earth as we know it. </p>
<p>This is different to how non-avian dinosaurs fared, who disappeared in their entirety: their entire branch was pruned. </p>
<p>Scientists believe <a href="https://genome.cshlp.org/content/24/8/1334.short">angiosperm resilience</a> to the K-Pg mass extinction (why only leaves and branchlets of the angiosperm tree were pruned) may be explained by their ability to adapt. For example, their evolution of new seed-dispersal and pollination mechanisms. </p>
<p>They can also <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2017.0912">duplicate their entire genome</a> (all of the DNA instructions in an organism) which provides a second copy of every single gene on which selection can act, potentially leading to new forms and greater diversity.</p>
<p>The sixth mass extinction event <a href="https://www.science.org/doi/full/10.1126/sciadv.1400253">we currently face</a> may follow a similar trajectory. A worrying number of angiosperm species are already threatened with extinction, and their demise will probably lead to the end of life as we know it. </p>
<p>It’s true angiosperms may blossom again from a stock of diverse survivors - and they may outlive us.</p><img src="https://counter.theconversation.com/content/213271/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jamie Thompson received PhD funding from Roger and Sue Whorrod (University of Bath alumni and philanthropists).</span></em></p>The fossil record tells conflicting stories about what happened to flowering plants after the asteroid.Jamie Thompson, Postdoctoral Evolutionary Biologist, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2010482023-09-05T15:15:03Z2023-09-05T15:15:03ZIt’s reassuring to think humans are evolution’s ultimate destination – but research shows we may be an accident<figure><img src="https://images.theconversation.com/files/545334/original/file-20230829-39956-1wo46w.jpg?ixlib=rb-1.1.0&rect=29%2C41%2C3964%2C2203&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Cambrian explosion, about 530 million years ago, was when most of the major groups of animals first appear in the fossil record. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/cambrian-explosion-radiation-3d-illustration-2056062350">canbedone/Shutterstock</a></span></figcaption></figure><p>Depending upon how you do the counting, there are <a href="https://education.nationalgeographic.org/resource/biodiversity/">around 9 million species</a> on Earth, from the simplest single-celled organisms to humans. </p>
<p>It’s reassuring to imagine that complex bodies <a href="https://www.nationalgeographic.com/science/article/brain-2#">and brains like ours</a> are the inevitable consequence of evolution, as if evolution had a goal. Unfortunately for human egos, <a href="https://www.nature.com/articles/s41559-023-01982-5">a recent study</a> comparing over a thousand mammals – the group we belong to – painted a less gratifying picture. </p>
<p>Evolutionary biologists in the late 18th century, including <a href="https://en.wikipedia.org/wiki/Jean-Baptiste_Lamarck">Jean-Baptiste Lamarck</a>, reasoned that life must have an innate tendency to evolve into ever more complex forms, and believed this reflected God’s design. However, by the mid-19th century, Charles Darwin showed that natural selection has no direction, and will sometimes make organisms simpler. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/513285/original/file-20230302-28-593rld.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/513285/original/file-20230302-28-593rld.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513285/original/file-20230302-28-593rld.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513285/original/file-20230302-28-593rld.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513285/original/file-20230302-28-593rld.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513285/original/file-20230302-28-593rld.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513285/original/file-20230302-28-593rld.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>Modern biologists agree that the most complex organisms have become more complex over the last 4 billion years, but <a href="https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-008-0055-6">they disagree about</a> what sort of process accounts for this. </p>
<p>Because most organisms are still very simple, one possibility is that maximum complexity has increased “accidentally”, like the diffusion of a drop of ink in a glass of water. If true, this could be a blow to our <a href="https://www.youtube.com/watch?v=FM-LnEUn5Xk">human sense of significance</a> as the most complex organisms. </p>
<p>Another theory is that increasing complexity is driven, on average, by <a href="https://www.nhm.ac.uk/discover/what-is-natural-selection.html">natural selection</a>. Sometimes selection acts on many, independent branches of the tree of life in a similar way and in parallel. This can produce similar effects in many of those branches and is known as a <a href="https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-008-0055-6">driven trend</a>.</p>
<p>While driven trends need not imply divine purpose, they at least suggest that complexity was mostly an improvement, which is reassuring for us humans.</p>
<p>So which pattern is the most common in the evolution of complexity: accidental diffusion or driven trend? </p>
<p>Most changes and mutations are bad, and these variants are usually weeded out through <a href="https://www.bbc.co.uk/bitesize/guides/zmf9xyc/revision/4#:%7E:text=in%20either%20environment.-,Stabilising,-In%20stabilising%20selection?">a process called stabilising selection</a>, which acts to maintain the status quo. But if most mutations make things function less well, doesn’t this make it very difficult for evolutionary novelties to arise? </p>
<p>In fact, evolution often operates on <a href="https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-008-0053-8">multiple copies of things</a>. For example, a single gene might be duplicated <a href="https://academic.oup.com/genetics/article/168/3/1421/6059626">within the same organism</a>. </p>
<p>Provided one copy maintains its original function, the other copy can accumulate mutations without putting its bearer at an immediate disadvantage. These mutated copies are usually edited out over time, but occasionally they acquire a new function that gives an advantage.</p>
<p>Even more remarkably, whole genomes – every single gene in an organism – <a href="https://www.nature.com/articles/s41467-020-17605-7">can be duplicated</a> in one generation. Under these circumstances, there are many chances that copies of some genes <a href="https://academic.oup.com/bfg/article/17/5/329/4951518">will acquire a new function</a>.</p>
<p>For example, <a href="https://www.britannica.com/animal/chondrostean">sturgeons and paddle fishes</a> underwent a whole genome duplication 250 million years ago, and this may explain how they survived <a href="https://www.tcd.ie/news_events/articles/2023/geneticists-discover-hidden-whole-genome-duplication-that-may-explain-why-some-species-survived-mass-extinctions/">the biggest ever mass extinction</a> that wiped out <a href="https://earth.stanford.edu/news/what-caused-earths-biggest-mass-extinction">96% of other marine species</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=200&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=200&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=200&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=252&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=252&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513381/original/file-20230303-26-d95w1o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=252&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Millipedes have lots of pairs of legs that are essentially identical. Shrimps have fewer pairs of legs but with many different functions.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Side_view_of_a_North_American_millipede.jpg%20/%20https://www.flickr.com/photos/a_semenov/48196502947/in/photostream/">photochem_PA/Alexander Semenov</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Identical copies of structures such as segments and limbs can also be made via duplication processes. For example, millipedes have lots of legs, but they are the same design copied lots of times. </p>
<p>Shrimps, by contrast have many <a href="https://www.nature.com/articles/41710">different types of legs</a> modified for feeding, walking, swimming and brooding eggs. A biological principle called the <a href="https://www.nature.com/articles/466318a">zero force evolutionary law</a> states that these copies will tend to become less similar by accidental diffusion alone, unless stabilising selection acts to keep the status quo. Of course, natural selection may also act to make the copies less similar if this has an advantage. </p>
<p>Our paper shows that increasing complexity in mammals has both diffusive and driven aspects. Rather than <a href="https://youtu.be/BS3loLR-QtM">marching towards greater complexity</a>, mammals evolved in lots of different directions, with only some lineages pushing the upper bounds of complexity. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Skeleton of a cat" src="https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513445/original/file-20230303-14-n47gyk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The spine of the domestic cat has several different types of vertebrae doing different jobs.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Felis_catus_skeleton_noBG.jpg">Kirill Tsukanov/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Surely nature selects for complexity just a bit?</h2>
<p>Unfortunately, there is little research addressing this question. One of the <a href="https://www.pnas.org/doi/10.1073/pnas.0709378105">few published studies</a> demonstrates that crustaceans (crabs, lobsters, shrimps and their relatives) evolved with a driven trend for increasing complexity over the last half a billion years. </p>
<p>Like crustaceans, and all vertebrates, we have bodies made of
repeating blocks of tissue (called somites). These are most visible in our vertebral column (or spine) and ribs, and in the six-pack of a lean athlete. Across mammals, the number of vertebrae (the bones that make up the spine) varies and they are shaped to do different jobs in the <a href="https://www.nsf.gov/news/news_summ.jsp?cntn_id=296527">neck, thorax, back, sacrum and tail</a>. </p>
<p>Counting the number of bones in different regions can quantify <a href="https://doi.org/10.1098/rsos.200895">one aspect of complexity</a> across all mammals. <a href="https://www.nature.com/articles/s41559-023-01982-5">In our study</a> sampling over a thousand mammal species, many groups – including whales, bats, rodents, carnivores and, our own group, the primates – independently evolved complex vertebral columns. This suggests higher complexity can be a winning formula, and that selection is driving this in multiple branches of the mammal tree. </p>
<p>However, many other branches have a low plateau in complexity or even become simpler. Elephants, rhinos, sloths, manatees, armadillos, golden moles and platypuses all thrived despite the fact they have relatively simple vertebral columns. The direction of evolution all depends on context. </p>
<figure class="align-center ">
<img alt="Two circles, red, blue with animals around outside." src="https://images.theconversation.com/files/513469/original/file-20230304-26-xqb0n8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/513469/original/file-20230304-26-xqb0n8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=273&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513469/original/file-20230304-26-xqb0n8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=273&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513469/original/file-20230304-26-xqb0n8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=273&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513469/original/file-20230304-26-xqb0n8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=343&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513469/original/file-20230304-26-xqb0n8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=343&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513469/original/file-20230304-26-xqb0n8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=343&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In a study of 1,136 mammal species, we find a driven trend for increasing complexity in multiple parallel lineages. Left hand panel is the number of vertebrae. Right hand panel is our index of complexity. Blue lines are lower values, while red lines are higher values.</span>
<span class="attribution"><span class="source">Li et al; Nature Ecology & Evolution (2023)</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Research into the evolution of complexity has only recently started gathering pace, so there is much we still don’t know. But we do know that the story of mammalian evolution hasn’t been a directional “<a href="https://www.sapiens.org/biology/evolution-march-of-progress/">march of progress</a>”, but rather has many characteristics of a random and diffusive walk.</p><img src="https://counter.theconversation.com/content/201048/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Wills receives funding from BBSRC, NERC, The Leverhulme Trust and The John Templeton Foundation</span></em></p><p class="fine-print"><em><span>Marcello Ruta receives funding from the John Templeton Foundation</span></em></p>We may have become the most complex living creature in part by accident and replication of error.Matthew Wills, Professor of Evolutionary Palaeobiology at the Milner Centre for Evolution, University of BathMarcello Ruta, Senior Lecturer, Life Sciences, University of LincolnLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2120492023-08-24T14:55:46Z2023-08-24T14:55:46ZHow do coral reefs thrive in parts of the ocean that are low in nutrients? By eating their algal companions<figure><img src="https://images.theconversation.com/files/544330/original/file-20230823-36239-dk7lmg.jpg?ixlib=rb-1.1.0&rect=31%2C25%2C4233%2C3088&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coral reefs are hotspots of productivity in otherwise nutrient-poor parts of our oceans.</span> <span class="attribution"><span class="source">Joerg Wiedenmann & Cecilia D'Angelo/University of Southampton</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Coral reefs thrive in parts of the world’s oceans that are low in nutrients. This mystery has puzzled scientists for centuries and has become known as the <a href="https://www.nhm.ac.uk/discover/charles-darwin-coral-conundrum.html">“Darwin paradox of coral reefs”</a>.</p>
<p>Our <a href="https://doi.org/10.1038/s41586-023-06442-5">new study</a> adds the missing piece of the puzzle. We found that many species of coral <a href="https://youtu.be/DsQO_1sB5is">cultivate and feed on</a> the microscopic algae that live inside their cells. This vegetarian diet allows the corals to tap into a large pool of nutrients that was previously considered unavailable to them.</p>
<p><a href="https://www.britannica.com/animal/coral">Stony corals</a> are soft-bodied animals made up of many individual polyps that live together as a colony. They secrete limestone skeletons that form the foundation of reefs. The coral polyps acquire nutritious compounds rich in nitrogen and phosphorus by catching prey like <a href="https://www.britannica.com/science/zooplankton">zooplankton</a> with their tentacles. </p>
<p>Many coral animals are also dependent on a symbiosis – a mutually beneficial relationship – with the microscopic algae that live inside their cells. These photosynthetic algae produce large amounts of carbon-rich compounds, such as sugars, and transfer them to the host coral to generate energy. However, as most photosynthetic products are deficient in nitrogen and phosphorous, they cannot sustain the growth of the animals. </p>
<p>Our findings suggest that, while coral animals may survive brief periods of starvation by feeding on their symbionts, some coral reefs could face the risk of prolonged nutrient deficiency due to global warming. This is concerning. Coral reefs are <a href="https://www.unep.org/explore-topics/oceans-seas/what-we-do/protecting-coral-reefs/why-protecting-coral-reefs-matters">important underwater ecosystems</a> that provide a home and feeding ground for countless organisms, sustaining around 25% of the world’s ocean biodiversity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Symbiont algae from a reef coral viewed under a microscope." src="https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=535&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=535&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=535&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=672&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=672&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544337/original/file-20230823-21-dat40a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=672&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Symbiont algae from a reef coral viewed under a microscope.</span>
<span class="attribution"><span class="source">J. Wiedenmann & C. D’Angelo/University of Southampton</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Vegetarian diet</h2>
<p>The symbiotic algae living within the corals are very efficient at taking up dissolved inorganic nutrients, like nitrate and phosphate, from the surrounding seawater. Even in nutrient-poor areas of the ocean, these compounds are present in considerable amounts as excretion products of organisms, <a href="https://www.nature.com/articles/35099547">such as sponges</a>, that live close by. Ocean currents can also <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/ecog.04097">transport these nutrients</a> to reefs. </p>
<p>The coral host, on the other hand, cannot absorb or use nitrate and phosphate directly. But, through a series of long-term laboratory experiments, we demonstrated that corals actually digest some of their symbiont population to access the nitrogen and phosphorus that these algae absorb from the water. </p>
<p>To provide evidence that the nutrients accumulated by the growing coral tissue originated from the symbionts, we supplied the corals with a chemical form of nitrogen that can only be absorbed from the water by the symbionts, not by the coral host.</p>
<p>This nutrient compound was marked by a technique called <a href="https://www.sciencedirect.com/science/article/pii/S0039914018309226">isotopic labelling</a>, which uses nitrogen atoms that are heavier than normal. These “heavy” isotopes allowed us to track the movement of nitrogen between the partners of the symbiosis by ultrasensitive detection methods. </p>
<p>With this method, we could unambiguously demonstrate that the nitrogen atoms that sustained the growth of the coral tissue were derived from the dissolved inorganic nutrients that were fed to their symbiont algae.</p>
<p>Our data suggest that most species of symbiotic corals can supplement their nutrition through such a vegetarian diet.</p>
<h2>From the laboratory to the ocean</h2>
<p>Together with our <a href="https://doi.org/10.1038/s41586-023-06442-5">colleagues</a>, we also analysed corals growing around remote islands in the Indian Ocean, some with seabirds on them and some without. Our results show that corals have the potential to farm and feed on their symbiont algae in the wild too. </p>
<p>The reefs around some of these islands are supplied with substantial amounts of nutrients that come from “guano” – the excrement of seabirds nesting on the islands. On some of the other islands, seabird colonies <a href="https://www.nature.com/articles/s41586-018-0202-3">have been decimated</a> by invasive rats. The reefs surrounding these islands receive fewer nutrients. </p>
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Read more:
<a href="https://theconversation.com/invasive-rats-are-changing-fish-behaviour-on-coral-reefs-new-study-197215">Invasive rats are changing fish behaviour on coral reefs – new study</a>
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<p>We measured the growth of <a href="https://www.nationalgeographic.com/animals/invertebrates/facts/staghorn-coral">staghorn coral</a> colonies both around islands with and without dense seabird populations and found that growth was more than twice as fast on reefs that were supplied with seabird nutrients. About half of the nitrogen molecules in the tissue of the coral animals from islands with seabirds could be traced back to uptake by the symbiont algae.</p>
<figure class="align-center ">
<img alt="A group of seabirds above a tropical beach." src="https://images.theconversation.com/files/544331/original/file-20230823-7859-833k3d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544331/original/file-20230823-7859-833k3d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544331/original/file-20230823-7859-833k3d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544331/original/file-20230823-7859-833k3d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544331/original/file-20230823-7859-833k3d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544331/original/file-20230823-7859-833k3d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544331/original/file-20230823-7859-833k3d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Reefs around islands in the Indian Ocean receive additional nutrients if the islands are inhabited by seabirds.</span>
<span class="attribution"><span class="source">N. Graham/Lancaster University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Global warming could complicate matters</h2>
<p>In the future, some coral reefs could face a <a href="https://www.nature.com/articles/ncomms10581">decrease in nutrient availability</a> due to global warming. Research suggests that warming surface waters are <a href="https://www.nature.com/articles/nature05317">less likely to</a> receive nutrients from deeper water layers. The reduced water productivity could result in fewer nutrients for their symbionts and subsequently less food for the coral animals. </p>
<p>Our study indicates that some coral reefs might become vulnerable to starvation as ocean temperatures warm. When we moved corals from water with ample nutrients to water with fewer nutrients, they continued to eat their symbiont algae. This behaviour allowed them to sustain their growth for a few weeks, even in the absence of feeding.</p>
<p>But once they had exhausted their population of symbiotic algae, the coral underwent bleaching (referring to the white appearance of the corals with low symbiont numbers in their tissue), stopped growing – and in some cases eventually died.</p>
<figure class="align-center ">
<img alt="Two photos comparing coral growth in different environments." src="https://images.theconversation.com/files/544334/original/file-20230823-15-yzs1p7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544334/original/file-20230823-15-yzs1p7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=526&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544334/original/file-20230823-15-yzs1p7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=526&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544334/original/file-20230823-15-yzs1p7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=526&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544334/original/file-20230823-15-yzs1p7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=661&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544334/original/file-20230823-15-yzs1p7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=661&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544334/original/file-20230823-15-yzs1p7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=661&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Corals grew fast in nutrient-rich water despite the absence of food (top). Corals in nutrient-depleted water stopped growing and showed a bleached appearance (bottom).</span>
<span class="attribution"><span class="source">L. Mardones-Velozo, C. D’Angelo & J. Wiedenmann, University of Southampton</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Our findings reveal that corals can not only acquire nitrogen and phosphorus by feeding on prey as other animals do. But, by eating parts of their symbiont stock, they can also efficiently tap into the pool of dissolved inorganic nitrogen and phosphorus that is otherwise only accessible to plants.</p>
<p>Through this process, symbiotic corals gain an advantage over other animals in environments that are low in nutrients, explaining their prominent role in the formation of reefs in nutrient-poor water. </p>
<p>However, increasingly severe nutrient depletion will add a further threat to some coral reefs already experiencing bleaching caused by heat stress.</p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<hr><img src="https://counter.theconversation.com/content/212049/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jörg Wiedenmann receives funding from Natural Environment Research Council (NERC) (NE/T001364/1).
Paul Wilson and Peter Franklin (University of Southampton) and Nick Graham (Lancaster University) contributed to the press release that fomed the basis of this article.</span></em></p><p class="fine-print"><em><span>Cecilia D'Angelo receives funding from Natural Environment Research Council NERC (NE/T001364/1). </span></em></p>Reef corals grow vigorously in nutrient poor water – new research has found out why.Jörg Wiedenmann, Professor of Biological Oceanography & Head of the Coral Reef Laboratory, University of SouthamptonCecilia D'Angelo, Associate Professor, Coral Reef Laboratory, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2073752023-06-12T15:00:40Z2023-06-12T15:00:40ZColonialism has shaped scientific plant collections around the world – here’s why that matters<figure><img src="https://images.theconversation.com/files/531254/original/file-20230611-84609-t8xxx2.jpg?ixlib=rb-1.1.0&rect=36%2C0%2C4813%2C3228&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Digitizing plants preserved in the herbarium at La Sapienza University in Rome.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/rome-la-sapienza-museum-complex-herbarium-museum-the-news-photo/1401716985">Mimmo Frassineti/AGF/Universal Images Group via Getty Images</a></span></figcaption></figure><p>Some of the <a href="https://theculturetrip.com/north-america/usa/articles/the-15-most-visited-museums-in-the-world/">world’s most popular museums</a> are natural history collections: Think of dinosaur fossils, gemstones and preserved animals. Herbaria – collections of pressed, dried plant specimens – are a less-known but important type of natural history collection. There are some <a href="https://sweetgum.nybg.org/science/ih/">400 million botanical specimens</a> stored across over 3,500 herbaria around the world, but most are not widely publicized and rarely host public exhibits. </p>
<p>I study <a href="https://scholar.google.com/citations?user=BF2WtIYAAAAJ&hl=en">biodiversity and global change</a>, and these collections have fueled my work. My collaborators and I have used herbarium collections to study how <a href="https://doi.org/10.1098/rstb.2017.0394">flowering times respond to changes in climate</a>, how dispersal traits and environmental preferences <a href="https://doi.org/10.1111/mec.13227">affect the likelihood that plants will become invasive</a>, and <a href="https://doi.org/10.1038/s41586-021-03876-7">how fires affect tropical biodiversity</a>. </p>
<p>I have had easy access to specimens from every corner of the world, but most researchers are not as lucky. This is partly because herbaria as we know them today are largely a European creation. And like other natural history collections, many of them grew as imperial powers expanded their colonial empires and <a href="https://digpodcast.org/2018/04/29/natural-history-museums/">amassed all kinds of resources</a> from their colonies. Today, over 60% of herbaria and 70% of specimens are located in developed countries with colonial histories. </p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/6XV5DyOTlV/?utm_source=ig_web_copy_link\u0026igshid=MzRlODBiNWFlZA==","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>My colleagues and I wanted to understand how many herbarium specimens <a href="https://www.nature.com/articles/s41562-023-01616-7">are not where the plants originated</a> and are housed in former colonizing countries instead. Our international team of researchers from herbaria on every continent analyzed over 85 million plant specimen records from the <a href="https://www.gbif.org/">Global Biodiversity Information Facility</a>, the largest online repository of biodiversity data, and also surveyed physical herbarium collections across the world. </p>
<p>We found that many former colonial powers have more plant diversity in their herbarium cabinets than they do in nature. Our data suggest that this is not the case, however, for former colonies, whose herbaria often house fewer plant species in their collections than are found naturally in the region. This disparity can limit former colonies’ capacity for botanical research. </p>
<h2>A persistent colonial legacy</h2>
<p>Herbaria are centers of botanical discovery and research, and are critical for understanding the diversity of plants and fungi around the world. The specimens they hold were originally collected to document and classify species. Today scientists use them for additional purposes, such as reconstructing plant evolutionary history, tracking pollution trends and identifying potential new drugs. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/bKcRUloQm0M?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Researchers at the Royal Botanic Garden in Edinburgh explain how the collection supports biodiversity research and conservation projects around the world.</span></figcaption>
</figure>
<p>Botany was <a href="https://www.plantsandculture.org/botanical-gardens-and-colonialism">the science par excellence of colonial empires</a>. Botanists moved numerous living and preserved plant specimens to institutions in colonizing nations which sought to exploit their colonies’ biological resources. </p>
<p>For instance, physician and naturalist <a href="https://www.britishmuseum.org/about-us/british-museum-story/sir-hans-sloane">Hans Sloane</a>, often credited as the inventor of chocolate milk, acquired numerous plant specimens from overseas colonies via his connections with the slave trade. His collections formed the basis of Britain’s <a href="https://www.nhm.ac.uk/">Natural History Museum</a>. Well-known scientists, including <a href="https://www.smithsonianmag.com/science-nature/charles-darwin-botanist-orchid-flowers-validate-natural-selection-180971472/">Charles Darwin</a> and <a href="https://www.nhm.ac.uk/our-science/departments-and-staff/library-and-archives/collections/linnaean-collection.html">Carl Linnaeus</a> and their disciples, relocated large numbers of plants from across the globe to European museums and collections.</p>
<p>Our analyses of online specimen records suggest that botanical collection trends over the past four centuries have been shaped by colonialism. Even though overt colonialism ended after World War II, specimens have largely continued to move from Africa, Asia and South America to institutions in Europe and North America, with a few exceptions.</p>
<p>Similarly, when we examined physical herbarium collections, we found that those in developed nations in the Global North that were former colonizers housed a higher proportion of internationally collected specimens on average. Herbaria in the U.S. and several European nations house specimens of over twice the number of species that naturally occur in these nations. </p>
<p>In nature, plant diversity is typically greatest in regions near the equator and decreases northward and southward toward the poles. Our data suggest that centuries of colonialism had the opposite effect: Plant specimens were moved away from countries with high natural plant diversity to collections in countries where fewer plant species occur naturally. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dried plant with four large leaves and a flower, captioned with a scientific description." src="https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=841&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=841&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=841&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1057&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1057&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531255/original/file-20230611-201874-wx78ok.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1057&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Ruellia tubiflora</em>, a tropical plant collected from Venezuela in 2001, preserved in the collection of Chicago’s Field Museum of Natural History.</span>
<span class="attribution"><a class="source" href="https://plantidtools.fieldmuseum.org/en/rrc/catalogue/322388">Field Museum</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>The digital divide</h2>
<p>As herbaria digitize their specimens and share data online, they are becoming somewhat more decentralized and democratic. Open-access data repositories, such as <a href="https://www.gbif.org/">the Global Biodiversity Information Facility</a>, allow researchers from around the world to query aggregated specimen metadata and images over the internet. This reduces the need to ship fragile specimens over long distances, and to take extensive and costly research trips. </p>
<p>But digitization requires large investments in equipment and personnel, which small institutions and developing countries often can’t afford. Stable internet connections are not always widely available in developing countries either. Further, our survey of herbaria indicates that digitization still has a long way to go. </p>
<p>We estimated that in general, fewer than 30% of physical collections have information online that at least describes when and where specimens were collected, and fewer than 10% have digital images available online. Most herbaria that responded to our inquiries were located in developed countries, so these figures probably overestimate the state of specimen digitization. The disparity in access to herbarium collections exists in the digital realm as well.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1654573880160157696"}"></div></p>
<h2>Making global plant collections more inclusive</h2>
<p>Many natural history museums and other cultural institutions are working now to <a href="https://www.sapiens.org/culture/museum-restitution/">address their colonial legacies</a>. This often includes acknowledging items in their collections that were acquired <a href="https://www.smithsonianmag.com/smart-news/harvard-museum-apologizes-for-owning-700-hair-samples-of-native-american-children-180981135/">unethically</a> or <a href="https://projectarchaeology.org/2021/03/19/modern-issues-in-archaeology-the-illegal-artifact-trade/">illegally</a>, and sometimes returning them to their original sources. But botanical collections have received less attention, maybe because few of them offer public displays. </p>
<p>Our study shows that there is a large disparity between where plant diversity naturally exists and where it is artificially housed and cataloged. As a result, many countries rely on botanical knowledge and resources housed outside of their own borders. </p>
<p>My colleagues and I believe that herbaria should be part of the ongoing movement to decolonize cultural institutions, natural history museums and related scientific practices. Key steps would include:</p>
<p>– Openly acknowledging the colonial legacy of herbarium collections, and communicating their history;</p>
<p>– Improving access to the vast information held in herbaria worldwide; and</p>
<p>– Building capacity in previously colonized countries by sharing knowledge and resources for contributing to research. These could include, for instance, supporting the local collection and study of plant diversity by providing training for local scientists. </p>
<p>In our view, the science that comes from botanical collections is globally relevant, so access to these resources should be within reach of the global community. Herbarium collections are critical to modern understanding of the world’s plants, and they have played key roles in numerous scientific discoveries and advances. Imagine how much more would be possible if these invaluable resources were available to all.</p><img src="https://counter.theconversation.com/content/207375/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Park does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The colonial era profoundly shaped natural history museums and collections. Herbaria, which are scientists’ main source of plant specimens from around the world, are no exception.Daniel Park, Assistant Professor of Biological Sciences, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2020112023-04-05T12:24:51Z2023-04-05T12:24:51ZRacist and sexist depictions of human evolution still permeate science, education and popular culture today<figure><img src="https://images.theconversation.com/files/518818/original/file-20230331-1042-s84ty.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2048%2C1367&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Human evolution is typically depicted with a progressive whitening of the skin, despite a lack of evidence to support it.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Stone_age_by_Vasnetsov_01.jpg">Viktor Mikhailovich Vasnetsov/Wikimedia Commons</a></span></figcaption></figure><p>Systemic racism and sexism have <a href="https://doi.org/10.1007/978-3-319-70401-2">permeated civilization</a> since the rise of agriculture, when people started living in one place for a long time. Early Western scientists, such as Aristotle in ancient Greece, were indoctrinated with the <a href="http://www.beacon.org/Superior-P1495.aspx">ethnocentric</a> and <a href="https://www.akpress.org/a-brief-history-of-misogyny.html">misogynistic</a> narratives that permeated their society. More than 2,000 years after Aristotle’s writings, <a href="http://www.beacon.org/Inferior-P1278.aspx">English naturalist Charles Darwin</a> also extrapolated the sexist and racist narratives he heard and read in his youth to the natural world. </p>
<p>Darwin presented his biased views as scientific facts, such as in his 1871 book “<a href="https://www.worldcat.org/title/39301709">The Descent of Man</a>,” where he described his belief that men are evolutionarily superior to women, Europeans superior to non-Europeans and hierarchical civilizations superior to small egalitarian societies. In that book, which <a href="https://www.smithsonianmag.com/science-nature/how-darwins-descent-man-holds-150-years-after-publication-180977091/">continues to be studied</a> in schools and natural history museums, he considered “the hideous ornaments and the equally hideous music admired by most savages” to be “not so highly developed as in certain animals, for instance, in birds,” and compared the appearance of Africans to the New World monkey <em>Pithecia satanas</em>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/xz8bsX2rWt4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Science isn’t immune to sexism and racism.</span></figcaption>
</figure>
<p>“The Descent of Man” was published during a moment of societal turmoil in continental Europe. In France, the working class <a href="https://www.britannica.com/event/Commune-of-Paris-1871">Paris Commune</a> took to the streets asking for radical social change, including the overturning of societal hierarchies. Darwin’s claims that the subjugation of the poor, non-Europeans and women was the natural result of evolutionary progress were music to the ears of the elites and those in power within academia. Science historian <a href="https://scholar.google.com/citations?user=OCG87poAAAAJ&hl=en">Janet Browne</a> wrote that Darwin’s <a href="https://press.princeton.edu/books/paperback/9780691114392/charles-darwin">meteoric rise within Victorian society</a> did not occur despite his racist and sexist writings but in great part because of them. </p>
<p>It is not coincidence that Darwin had a state funeral in Westminster Abbey, an honor emblematic of English power, and was <a href="https://www.worldcat.org/title/darwin/oclc/644948405">publicly commemorated</a> as a symbol of “English success in conquering nature and civilizing the globe during Victoria’s long reign.” </p>
<p>Despite the significant societal changes that have occurred in the last 150 years, sexist and racist narratives are still common in <a href="https://doi.org/10.1002/evan.21978">science, medicine and education</a>. As a <a href="https://scholar.google.com/citations?user=sOat2IwAAAAJ&hl=en">teacher and researcher</a> at Howard University, I am interested in combining my main fields of study, <a href="https://www.ruidiogolab.org/">biology and anthropology</a>, to discuss broader societal issues. In research I recently published with my colleague <a href="https://profiles.howard.edu/fatimah-jackson">Fatimah Jackson</a> and three medical students at Howard University, we show how racist and sexist narratives are not a thing of the past: They are still present in scientific papers, textbooks, museums and educational materials.</p>
<h2>From museums to scientific papers</h2>
<p>One example of how biased narratives are still present in science today is the numerous depictions of human evolution as a linear trend from darker and more “primitive” human beings to more “evolved” ones with a lighter skin tone. Natural history <a href="https://www.voanews.com/a/john-gurche-shaping-humanity/1836128.html">museums</a>, <a href="https://medium.com/paperkin/where-is-evolution-taking-the-human-race-6ddaf7eaddba">websites</a> and <a href="https://theculturetrip.com/africa/south-africa/articles/what-south-africas-caves-can-tell-you-about-humankind/">UNESCO heritage sites</a> have all shown this trend.</p>
<p>The fact that such depictions are not scientifically accurate does not discourage their continued circulation. <a href="https://www.yahoo.com/video/15-countries-largest-white-population-195712421.html">Roughly 11%</a> of people living today are “white,” or European descendants. Images showing a linear progression to whiteness do not accurately represent either human evolution or what living humans look like today, as a whole. Furthermore, there is no scientific evidence supporting a progressive skin whitening. <a href="https://doi.org/10.1002/ajpa.24564">Lighter skin pigmentation</a> chiefly evolved within just a few groups that migrated to non-African regions with high or low latitudes, such as the northern regions of America, Europe and Asia.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/2aFfDooTIVQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Illustrations of human evolution tend to depict progressive skin whitening.</span></figcaption>
</figure>
<p>Sexist narratives also still permeate academia. For example, in a 2021 paper on a famous early human fossil <a href="https://doi.org/10.4436/jass.99001">found in the Sierra de Atapuerca</a> archaeological site in Spain, researchers examined the canine teeth of the remains and found that it was actually that of a girl between 9 and 11 years old. It was previously believed that the fossil was a boy due to a popular 2002 book by one of the authors of that paper, paleoanthropologist <a href="https://scholar.google.com/citations?user=5nDp-kIAAAAJ">José María Bermúdez de Castro</a>. What is particularly telling is that the study authors recognized that there was no scientific reason for the fossil remains to have been designated as a male in the first place. The decision, they wrote, “<a href="https://newsrnd.com/news/2021-03-16-%0A---the-boy-from-the-gran-dolina-was-actually-a-girl%0A--.Skx4GEFC7u.html">arose randomly</a>.”</p>
<p>But these choices are not truly “random.” Depictions of human evolution <a href="https://www.cornellpress.cornell.edu/book/9780801435492/ancestral-images/">frequently only show men</a>. In the few cases where women are depicted, they tend to be shown as passive mothers, not as active inventors, cave painters or food gatherers, despite available anthropological data showing that <a href="http://www.beacon.org/Inferior-P1278.aspx">pre-historical women were all those things</a>.</p>
<p>Another example of sexist narratives in science is how researchers continue to discuss the “puzzling” <a href="https://doi.org/10.1002/jez.b.22690">evolution of the female orgasm</a>. Darwin <a href="https://doi.org/10.1007/978-3-319-70401-2">constructed narratives</a> about how women were evolutionarily “coy” and sexually passive, even though he acknowledged that females actively select their sexual partners in most mammalian species. As a Victorian, it was difficult for him to accept that women could play an active part in choosing a partner, so he argued that such roles only applied to women in early human evolution. According to Darwin, men later began to sexually select women.</p>
<p>Sexist narratives about women being more “coy” and “less sexual,” including the idea of the female orgasm as an evolutionary puzzle, <a href="https://www.iflscience.com/female-orgasms-are-not-puzzling-enigmas--43486">are contradicted</a> by a wide range of evidence. For instance, women are the ones who actually more frequently experience <a href="https://doi.org/10.1080/00224499.2020.1743224">multiple orgasms</a> as well as more <a href="https://doi.org/10.1080/00224490209552129">complex, elaborate and intense orgasms</a> on average, compared to men. Women are not biologically less sexual, but <a href="https://theconversation.com/data-should-smash-the-biological-myth-of-promiscuous-males-and-sexually-coy-females-59665">sexist stereotypes</a> were accepted as scientific fact.</p>
<h2>The vicious cycle of systemic racism and sexism</h2>
<p>Educational materials, including textbooks and anatomical atlases used by science and medical students, play a crucial role in perpetuating biased narratives. For example, the 2017 edition of “<a href="https://evolve.elsevier.com/cs/product/9780323547086?role=student">Netter Atlas of Human Anatomy</a>,” commonly used by medical students and clinical professionals, includes about 180 figures that show skin color. Of those, the vast majority show male individuals with white skin, and only two show individuals with “darker” skin. This perpetuates the depiction of white men as the anatomical prototype of the human species and fails to display the full anatomical diversity of people.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/mMVzPCOut1w?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Textbooks and educational materials can perpetuate the biases of their creators in science and society.</span></figcaption>
</figure>
<p>Authors of teaching materials for children also replicate the biases in scientific publications, museums and textbooks. For example, the cover of a 2016 coloring book entitled “<a href="https://books.google.com/books/about/The_Evolution_of_Living_Things_Coloring.html?id=mOUkMQAACAAJ">The Evolution of Living Things”</a>“ shows human evolution as a linear trend from darker "primitive” creatures to a “civilized” Western man. Indoctrination comes full circle when the children using such books become scientists, journalists, museum curators, politicians, authors or illustrators.</p>
<p>One of the key characteristics of systemic racism and sexism is that it is unconsciously perpetuated by people who often don’t realize that the narratives and choices they make are biased. Academics can address long-standing racist, sexist and Western-centric biases by being both more alert and proactive in detecting and correcting these influences in their work. Allowing inaccurate narratives to continue to circulate in science, medicine, education and the media perpetuates not only these narratives in future generations, but also the discrimination, oppression and atrocities that have been <a href="https://www.smithsonianmag.com/science-nature/disturbing-resilience-scientific-racism-180972243/">justified by them in the past</a>.</p><img src="https://counter.theconversation.com/content/202011/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rui Diogo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>From Aristotle to Darwin, inaccurate and biased narratives in science not only reproduce these biases in future generations but also perpetuate the discrimination they are used to justify.Rui Diogo, Associate Professor of Anatomy, Howard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1865802022-11-09T16:24:18Z2022-11-09T16:24:18ZThe study of evolution is fracturing – and that may be a good thing<figure><img src="https://images.theconversation.com/files/492997/original/file-20221102-42436-qk7an2.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C13274%2C8264&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/amazing-moment-monarch-butterfly-pupae-cocoons-1938757099">Darkdiamond67/Shutterstock</a></span></figcaption></figure><p>How will life on Earth and the ecosystems that support it adapt to climate change? Which species will go extinct – or evolve into something new? How will microbes develop further resistance to antibiotics? </p>
<p>These kinds of questions, which are of fundamental importance to our way of life, are all a focus for researchers who study evolution and will prove increasingly important as the planet heats up. </p>
<p>But finding the answers isn’t the only challenge facing evolutionary biology. Charles Darwin’s theories might be over 150 years old but major questions about how evolution works are far from settled. </p>
<p>Evolutionary biology is now undergoing one of the most intense debates it has had for more than a generation. And how this debate plays out could have a significant impact on the future of this scientific field.</p>
<p>Some biologists and philosophers claim that <a href="https://www.theguardian.com/science/2022/jun/28/do-we-need-a-new-theory-of-evolution">evolutionary biology needs reform</a>, arguing that traditional explanations for how organisms change through time that scientists have assumed <a href="https://www.oxfordbibliographies.com/view/document/obo-9780199941728/obo-9780199941728-0115.xml">since the 1930s</a> are holding back the assimilation of novel findings</p>
<p>Contemporary evolutionary biology, a vocal minority <a href="https://www.nature.com/articles/514161a">argue</a>, is incomplete. The dominant and traditional view of the field is too preoccupied with how the genes in a population change over time. This neglects, these critics argue, how individual organisms shape their environments and adjust themselves during their lifetimes to survive and reproduce.</p>
<p>Some go so far as to say that evolutionary theory itself is <a href="https://www.independent.co.ug/evolutionary-theorys-welcome-crisis/">in crisis</a> and must be <a href="https://journals.biologists.com/jeb/article/218/1/7/13568/Evolution-beyond-neo-Darwinism-a-new-conceptual">replaced</a> with something new. </p>
<p>Not all biologists <a href="https://royalsocietypublishing.org/doi/full/10.1098/rspb.2016.2864?etoc=">are convinced</a>. Some argue that repeated calls for reform are mistaken and can actually <a href="https://link.springer.com/article/10.1007/s10539-016-9557-8">hinder progress</a>.</p>
<figure class="align-center ">
<img alt="Three petri dishes arranged side by side." src="https://images.theconversation.com/files/493000/original/file-20221102-47877-k7qr16.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/493000/original/file-20221102-47877-k7qr16.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=240&fit=crop&dpr=1 600w, https://images.theconversation.com/files/493000/original/file-20221102-47877-k7qr16.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=240&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/493000/original/file-20221102-47877-k7qr16.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=240&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/493000/original/file-20221102-47877-k7qr16.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=302&fit=crop&dpr=1 754w, https://images.theconversation.com/files/493000/original/file-20221102-47877-k7qr16.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=302&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/493000/original/file-20221102-47877-k7qr16.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=302&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">How microbes develop resistance to antibiotics is evolution in action.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/antimicrobial-resistance-susceptibility-tests-by-diffusion-2035530317">MD_style/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Modern evolutionary theory</h2>
<p>The version of evolutionary biology that is still largely taught in schools has its origin in <a href="https://ecoevorxiv.org/gjf8s/">the modern synthesis</a>. This fused Gregor Mendel’s theory that organisms inherit discrete particles (what we now call genes) with Charles Darwin’s theory of natural selection. Darwin suggested that environmental conditions weed out heritable traits which are unhelpful and promote those which offer organisms an advantage.</p>
<p>The modern synthesis aimed to unify biology, but it was dominated by a few subfields, particularly genetics and paleontology, and focused on how populations change their genetic make-up over time. From this perspective, organisms are objects and the raw material for natural selection. </p>
<p>Notably, the modern synthesis did not incorporate all fields. The study of how embryos develop and how organisms interact with each other and their environment (ecology) were largely left out.</p>
<p>Organisms are not, critics of the modern synthesis argue, passive objects of natural selection. Instead, they say, organisms are agents that <a href="https://www.jstor.org/stable/j.ctt24hqpd">change those environments</a>. </p>
<p>A famous example is the beaver, which builds dams to survive and reproduce, changing its surroundings in the process. This tinkering in turn influences natural selection on itself and other species, thereby changing the beaver’s long-term evolution.</p>
<p>Organisms also inherit <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2015.1019">more than DNA</a>. This challenges the modern synthesis’s assumption that traits an organism acquires during a single lifetime cannot be passed down. </p>
<p>There is cultural transmission: <a href="https://www.nature.com/articles/ncomms11693">killer whales</a> teach their children and grandchildren hunting skills and food preferences. Songbirds transfer nutrients to new generations <a href="https://www.nature.com/articles/s42003-018-0247-8">in eggs</a> just as humans give their offspring antibodies through breast milk. Some biologists say that these endowments can revitalise the study of evolutionary biology, diverting our attention from strict genetic inheritance.</p>
<figure class="align-center ">
<img alt="A killer whale calf surfaces between two large dorsal fins." src="https://images.theconversation.com/files/493001/original/file-20221102-22-f16d5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/493001/original/file-20221102-22-f16d5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/493001/original/file-20221102-22-f16d5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/493001/original/file-20221102-22-f16d5x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/493001/original/file-20221102-22-f16d5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/493001/original/file-20221102-22-f16d5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/493001/original/file-20221102-22-f16d5x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The transmission of information between generations can influence a species’ evolution.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/killer-whale-calf-surfaces-surrounded-by-97761248">Monika Wieland Shields/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Diversity is a strength</h2>
<p>As an evolutionary ecologist with an interest in how organisms adapt to their environments, I am not as worried as some that the current version of evolutionary biology is incomplete. Neither am I particularly concerned about the limitations of population genetics. </p>
<p>Evolution can clearly be described as changing gene frequencies between generations. But this does not mean that population genetics is the only useful way to study evolution.</p>
<p>Biologists might disagree on what constitutes <a href="https://www.pnas.org/doi/10.1073/pnas.0702207104">an evolutionary process</a>, with natural selection and random changes in DNA being the two best studied processes. Evolutionary processes are not the only interesting aspect of evolution, though. </p>
<p>Evolutionary outcomes and the products of evolution – organisms and how they develop – also keep biologists busy. We have come to understand more about how genes and environments interact to shape the development of organisms. These insights from <a href="https://www.naturalhistorymag.com/features/061488/the-origins-of-form">evolutionary developmental biology</a> have clearly enriched our field. </p>
<p>That evolutionary biology is increasingly fractured does not worry me either, as long as we recognise that a plurality of approaches is not a weakness, but a strength. If physicists cannot agree upon a <a href="https://science.jrank.org/pages/3095/Grand-Unified-Theory.html">grand unified theory</a> of the universe, why should biologists expect to agree on one beyond what we have already achieved? After all, organisms are much more complex than physical particles and processes.</p>
<p>To take another example from physics, light can be viewed either as a particle or a wave. This <a href="https://www.britannica.com/science/wave-particle-duality">duality</a> reflects how a single descriptor is not enough to fully describe the complex phenomenon of light. </p>
<p>If this works for physicists, why could evolutionary biologists not also use multiple ways of studying a process as complex as evolution, and things as complex as organisms? Why can we not see organisms as either agents capable of modifying their environments or objects subject to natural selection, depending on the context? These are two valuable and complementary perspectives.</p>
<figure class="align-center ">
<img alt="A red dragonfly resting on a plant frond." src="https://images.theconversation.com/files/493051/original/file-20221102-26750-z6zxo3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/493051/original/file-20221102-26750-z6zxo3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=460&fit=crop&dpr=1 600w, https://images.theconversation.com/files/493051/original/file-20221102-26750-z6zxo3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=460&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/493051/original/file-20221102-26750-z6zxo3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=460&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/493051/original/file-20221102-26750-z6zxo3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=578&fit=crop&dpr=1 754w, https://images.theconversation.com/files/493051/original/file-20221102-26750-z6zxo3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=578&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/493051/original/file-20221102-26750-z6zxo3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=578&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Organisms influence – and are influenced by – natural selection.</span>
<span class="attribution"><span class="source">Erik Svensson</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Evolutionary biology today is a messy patchwork of <a href="https://link.springer.com/article/10.1007/s10539-016-9557-8">several loosely connected subfields</a>. This reflects the enormous diversity of phenomena that we study and the many interests of biologists. </p>
<p>We are united in accepting that natural selection on inheritance and random factors have jointly shaped organisms – but not by much more. Maintaining a coherent overview, either the modern synthesis or some extension to it, seems increasingly hopeless. </p>
<p>Giving up the search for a grand unified evolutionary theory will not hurt our field, but rather, liberate us. It will enable biologists to think more freely about <a href="https://www.seanbcarroll.com/endless-forms-most-beautiful">the endless forms most beautiful</a> that are constantly evolving and will continue to do so.</p><img src="https://counter.theconversation.com/content/186580/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Erik Svensson receives funding from from the Swedish Research Council (VR; grant no. 2020-03123). </span></em></p>There is more to evolution than the genes species inherit.Erik Svensson, Professor (Evolutionary Ecology Unit, Department of Biology), Lund UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1931232022-11-01T13:37:52Z2022-11-01T13:37:52ZLarge tortoises lived in South Africa long ago: how we recorded their fast-disappearing traces<figure><img src="https://images.theconversation.com/files/491294/original/file-20221024-5750-exbv3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Today, leopard tortoises are the largest species found on the Cape south coast. </span> <span class="attribution"><span class="source">Ava Peattie/Shutterstock</span></span></figcaption></figure><p>In 1835 Charles Darwin, the father of the theory of evolution, was exploring an island in the Galápagos archipelago when he <a href="https://www.biodiversitylibrary.org/page/19698213#page/438/mode/1up">encountered</a> “two large tortoises, each of which must have weighed at least two hundred pounds”. He had never seen anything like them. He became entranced by the animals and took <a href="https://www.theguardian.com/science/animal-magic/2014/feb/12/celebrity-pet-discovery-darwin-tortoise">at least one</a> back to England as a pet.</p>
<p>Large tortoises are still associated with the Galápagos Islands, about 1,000km off the coast of Ecuador, as well as <a href="https://nationalzoo.si.edu/animals/aldabra-tortoise">Aldabra Island</a> in the Seychelles.</p>
<p>Now, for the first time, evidence has been found to suggest that a species of very large tortoise once lived on South Africa’s Cape south coast. <a href="https://www.doi.org/10.1017/qua.2022.50">Our study</a> of fossil tracks indicates that, between 139,000 and 109,000 years ago, a tortoise species existed that was around 106cm long. This is not as big as the Galápagos tortoises, which can reach 150cm or more in length, but is significantly bigger than any tortoises in southern Africa today.</p>
<p>The period when these tortoises were wandering round the southern tip of Africa was called the <a href="https://www.livescience.com/40311-pleistocene-epoch.html">Pleistocene Epoch</a>. They shared the landscape with large animals like <a href="http://dx.doi.org/10.17159/sajs.2018/20170266">giraffes</a>, extinct giant buffalo, <a href="https://doi.org/10.17159/sajs.2020/6542">crocodiles</a> and <a href="https://doi.org/10.1017/qua.2019.40">breeding sea turtles</a>, none of which inhabit the region today. Our ancestors, <em>Homo sapiens</em>, <a href="https://sajs.co.za/article/view/8156">were also present</a>.</p>
<p>Today, the leopard tortoise (<em>Stigmochelys pardalis</em>) is the largest tortoise species in the area. The record length for a leopard tortoise is 70cm. Given the length of the tortoise in our findings – 106cm – we conclude that either the tracks were made by a previously unknown very large tortoise or that the leopard tortoises of the Pleistocene period were much larger.</p>
<p>Before this research, there was nothing to suggest the presence of very large tortoises from southern Africa in the region’s extensive archaeological record and body fossil record. Such findings demonstrate the capacity of ichnology – the study of tracks and traces – to complement and fill gaps in the traditional fossil record. And doing so doesn’t just create a fuller picture of ancient landscapes: it’s an important part of understanding what’s changed over time and the effects of climate change and humans.</p>
<h2>Tracks</h2>
<p>The fossil tracks were found in aeolianites (cemented dunes) and were made when these deposits consisted of unconsolidated sand. These sites would have been situated at the margin of the vast <a href="https://doi.org/10.1016/j.quascirev.2019.106161">Palaeo-Agulhas Plain</a>, which was alternately exposed and inundated during Pleistocene sea level oscillations.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/492509/original/file-20221031-25-jh1obc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/492509/original/file-20221031-25-jh1obc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/492509/original/file-20221031-25-jh1obc.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/492509/original/file-20221031-25-jh1obc.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/492509/original/file-20221031-25-jh1obc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/492509/original/file-20221031-25-jh1obc.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/492509/original/file-20221031-25-jh1obc.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The aeolianite block, showing the large tortoise tracks and traces (scale bar = 10cm)</span>
<span class="attribution"><span class="source">Charles Helm</span></span>
</figcaption>
</figure>
<p>The main tracksite was located east of Still Bay, around 340km from Cape Town, on a rugged, remote stretch of coastal cliffs. Here we were fortunate to intercept a large aeolianite block on its slow but relentless journey from the cliffs above, from which it had broken off, down a sandy slope to the sea below. </p>
<p>When we initially identified it, the track-bearing surface was covered in a thin veneer of sediment which preserved exquisite detail. Not only were two sets of parallel large tracks evident, but a number of traces were also present centrally between these sets of tracks, indicating where something large had scraped the surface and caused shallow parallel striations and other deeper impressions. </p>
<p>It was a good thing we found the block when we did: within a couple of weeks the veneer (with the parallel striations) had been eroded away by wind and water. Months later the block had disappeared into the ocean. </p>
<h2>A large trackmaker</h2>
<p>By then we had already photographed and measured the block, the tracks and the surrounding area. We also took rock samples to perform dating studies from sites west and east of the main tracksite through a technique known as <a href="https://doi.org/10.1146/annurev-earth-040610-133425">optically stimulated luminescence</a> and established that the tracks were probably made between approximately 139,000 years and 109,000 years ago. </p>
<p>After ruling out other possibilities, including large crocodiles and monitor lizards, it was evident that this trackway had been made by a large tortoise, and that the midline features were caused by the dragging of the plastron (the underside of the tortoise shell) and by the tail spearing the surface. </p>
<p>The trackway was 69cm wide. We studied tracks and traces of leopard tortoises for comparison, and used these to estimate that the trackmaker at our site was as much as 106cm long, at least 50% longer than the largest recorded leopard tortoises.</p>
<h2>Changing sizes over time</h2>
<p>Many species of giant tortoises on islands have become extinct <a href="https://doi.org/10.3854/crm.5.000e.fossil.checklist.v1.2015">in the last few centuries</a>. It would also not be unprecedented if what was once a giant species had evolved into a smaller species, the extant leopard tortoise. Tortoise giantism is a <a href="https://doi.org/10.1111/cla.12227">recurring theme</a> in the fossil record. </p>
<p>It is known that <a href="https://doi.org/10.1016/0033-5894(86)90089-X">some carnivorans</a>, <a href="https://doi.org/10.2989/00306525.2020.1789772">birds</a> and <a href="https://doi.org/10.1111/geb.12491">reptiles</a> were larger in some phases of the Pleistocene than today, so both possibilities are plausible.</p>
<p>Our team’s latest discovery adds a little more to the picture that both our and other scientists’ findings have painted of the ancient Cape south coast landscape. With each find, the image becomes clearer – and allows us to understand how it has shifted over time.</p><img src="https://counter.theconversation.com/content/193123/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charles Helm does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Track marks are a way to fill in the blanks that sometimes exist in the body fossil record.Charles Helm, Research Associate, African Centre for Coastal Palaeoscience, Nelson Mandela UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1850772022-06-23T15:02:57Z2022-06-23T15:02:57ZEvolutionary tree of life: modern science is showing how we got so much wrong<figure><img src="https://images.theconversation.com/files/469018/original/file-20220615-16-esfdjk.jpg?ixlib=rb-1.1.0&rect=41%2C0%2C3026%2C2037&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/lunkwill42/3658339290">Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>If you look different to your close relatives, you may have felt separate from your family. As a child, during particularly stormy fall outs you might have even hoped it was a sign that you were adopted. </p>
<p>As our new research shows, appearances can be deceptive when it comes to family. New DNA technology is shaking up the family trees of many plants and animals. </p>
<p>The primates, to which humans belong, were once thought to be close relatives of bats because of some similarities in our <a href="https://www.sciencedirect.com/science/article/abs/pii/0047248487900583">skeletons</a> and <a href="https://en.wikipedia.org/wiki/Flying_primate_hypothesis">brains</a>. However, DNA data now places us in a group that includes rodents (rats and mice) and rabbits. Astonishingly, bats turn out to be more closely related to cows, <a href="https://www.newscientist.com/article/dn9402-bats-and-horses-get-strangely-chummy/">horses</a> and even rhinoceroses than they are to us. </p>
<p>Scientists in Darwin’s time and through most of the 20th century could only work out the branches of the evolutionary tree of life by looking at the structure and appearance of animals and plants. Life forms were grouped according to <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cladistics">similarities thought to have evolved together</a>.</p>
<p>About three decades ago, scientists started using DNA data to build “molecular trees”. Many of the first trees based on DNA data were at odds with the classical ones. Sloths and anteaters, armadillos, pangolins (scaly anteaters) and aardvarks were once thought to belong together in a group called edentates (“no teeth”), since they share aspects of their anatomy. Molecular trees showed that these traits evolved independently in different branches of the mammal tree. It turns out that aardvarks are more closely related to elephants while pangolins are more closely related to cats and dogs. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/469364/original/file-20220616-19-fbkxgs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Molecular phylogenies show that mammals as different in appearance as aardvarks, manatees, elephant shrews and elephants are really close cousins.</span>
</figcaption>
</figure>
<h2>Coming together</h2>
<p>There is another important line of evidence that was familiar to Darwin and his contemporaries. <a href="https://www.youtube.com/watch?v=s5P4uYsK8_c#t=2m38s">Darwin noted</a> that animals and plants that appeared to share the closest common ancestry were often found close together geographically. The location of species is another strong indicator they are related: species that live near each other are more likely to share a family tree.</p>
<p>For the first time, our <a href="https://www.nature.com/articles/s42003-022-03482-x">recent paper</a> cross-referenced location, DNA data and appearance for a range of animals and plants. We looked at evolutionary trees based on appearance or on molecules for 48 groups of animals and plants, including bats, dogs, monkeys, lizards and pine trees. Evolutionary trees based on DNA data were two-thirds more likely to match with the location of the species compared with traditional evolution maps. In other words, previous trees showed several species were related based on appearance. Our research showed they were far less likely to live near each other compared to species linked by DNA data.</p>
<p>It may appear that evolution <a href="https://en.wikipedia.org/wiki/Endless_Forms_Most_Beautiful">endlessly invents new solutions</a>, almost without limits. But it has fewer tricks up its sleeve than you might think. Animals can look amazingly alike because they have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4633856/">evolved to do a similar job</a> or live in a similar way. Birds, bats and the extinct pterosaurs have, or had, <a href="https://theconversation.com/curious-kids-how-did-some-animals-evolve-wings-to-fly-148496">bony wings for flying</a>, but their ancestors all had front legs for walking on the ground instead. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=371&fit=crop&dpr=1 600w, https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=371&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=371&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=466&fit=crop&dpr=1 754w, https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=466&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/469784/original/file-20220620-22-falg17.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=466&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The colour wheels and key indicate where members of each order are found geographically. The molecular tree has these colours grouped together better than the morphological tree, indicating closer agreement of the molecules to biogeography. Figure is from Oyston et al. (2022)</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Similar wing shapes and muscles evolved in different groups because the physics of generating thrust and lift in air are always the same. It is <a href="https://www.youtube.com/watch?v=u6Ol_a9oV_M&t=73s">much the same with eyes</a>, which <a href="https://rdcu.be/cO0Xo">may have evolved 40 times in animals</a>, and with only a few basic “designs”. </p>
<p>Our eyes are similar to squid’s eyes, with a crystalline lens, iris, retina and visual pigments. Squid are more closely related to snails, slugs and clams than us. But many of their mollusc relatives have only the simplest of eyes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/469014/original/file-20220615-14-6hlcuq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Squid and fish are actually separated by more than half a billion years of evolution.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/pacificklaus/8751081489">Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Moles evolved as blind, burrowing creatures at least four times, on different continents, on different branches of the mammal tree. The Australian marsupial pouched moles (more closely related to kangaroos), African golden moles (more closely related to aardvarks), African mole rats (rodents) and the Eurasian and North American talpid moles (beloved of gardeners, and more closely related to hedgehogs than these other “moles”) all evolved down a similar path. </p>
<h2>Evolution’s roots</h2>
<p>Until the advent of cheap and efficient gene sequencing technology in the 21st century, appearance was usually all evolutionary biologists had to go on.</p>
<p>While Darwin (1859) showed that all life on Earth is related in a single evolutionary tree, he did little to map out its branches. The anatomist Ernst Haeckel (1834-1919) was one of the first people to draw evolutionary trees that tried to show how major groups of life forms are related. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=445&fit=crop&dpr=1 600w, https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=445&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=445&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=559&fit=crop&dpr=1 754w, https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=559&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/469800/original/file-20220620-24-hhlhl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=559&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The german zoologist Ernst Haeckel’s illustrations (here, groups of mosses)</span>
<span class="attribution"><a class="source" href="https://pixabay.com/photos/moose-eurhynchium-haeckel-muscinae-63103/%20%20and%20https://en.wikipedia.org/wiki/Ernst_Haeckel#/media/File:Tree_of_life_by_Haeckel.jpg">Pixaby</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Haeckel’s drawings made brilliant observations of living things that influenced art and design in the 19th and 20th centuries. His family trees were based almost entirely on how those organisms looked and developed as embryos. Many of his ideas about evolutionary relationships were held until recently. As it becomes easier and cheaper to obtain and analyse large volumes of molecular data, there will be many more surprises in store.</p><img src="https://counter.theconversation.com/content/185077/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Wills receives funding from NERC and JTF grant 61408</span></em></p>DNA analysis is beginning to reveal how wrong the long-accepted evolutionary tree is.Matthew Wills, Professor of Evolutionary Palaeobiology at the Milner Centre for Evolution, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1836332022-05-26T20:37:16Z2022-05-26T20:37:16ZWild animals are evolving faster than anybody thought<figure><img src="https://images.theconversation.com/files/465409/original/file-20220526-26-6c6gst.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C2585%2C1919&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/family-superb-fairywrens-south-eastern-new-1291536274">Shutterstock</a></span></figcaption></figure><p>How fast is evolution? In adaptive evolution, natural selection causes genetic changes in traits that favour the survival and reproduction of individual organisms.</p>
<p>Although Charles Darwin thought the process occurred over geological timescales, we have seen examples of dramatic adaptive evolution over only a handful of generations. The <a href="https://en.wikipedia.org/wiki/Peppered_moth_evolution">peppered moth changed colour</a> in response to air pollution, poaching has driven some elephants to <a href="https://evolution.berkeley.edu/evo-news/the-evolution-of-tuskless-elephants-foils-poachers-but-at-a-cost/">lose their tusks</a> and <a href="https://evolution.berkeley.edu/evo-news/toxic-river-means-rapid-evolution-for-one-fish-species/">fish have evolved resistance to toxic chemicals</a>.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-theory-of-evolution-2276">Explainer: Theory of evolution</a>
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</em>
</p>
<hr>
<p>However, it is still hard to tell how fast adaptive evolution is currently occurring. We also don’t know whether it has a hand in the fate of populations challenged by environmental change.</p>
<p>To measure the speed of adaptive evolution in the wild, <a href="https://science.org/doi/10.1126/science.abk0853">we studied 19 populations of birds and mammals over several decades</a>. We found they were evolving at twice to four times the speed suggested by earlier work. This shows adaptive evolution may play an important role in how the traits and populations of wild animals change over relatively short periods of time.</p>
<h2>The tools of the evolutionary biologist: maths and binoculars</h2>
<p>How do we measure how fast adaptive evolution is occurring? According to the “<a href="https://en.wikipedia.org/wiki/Fisher%27s_fundamental_theorem_of_natural_selection">fundamental theorem of natural selection</a>”, the amount of genetic difference in “fitness” to survive and reproduce among individuals across a population also corresponds to the population’s rate of adaptive evolution.</p>
<p>The “fundamental theorem” has been known for 90 years, but it has been difficult to apply in practice. Attempts to use the theorem in wild populations have been rare, and are plagued by statistical problems. </p>
<figure class="align-center ">
<img alt="A four by two grid of photographs, showing a superb fairy-wren, hihi, song sparrow, blue tit, rhesus macaque, yellow baboon, snow vole and spotted hyena" src="https://images.theconversation.com/files/465243/original/file-20220525-12-1j6acq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/465243/original/file-20220525-12-1j6acq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/465243/original/file-20220525-12-1j6acq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/465243/original/file-20220525-12-1j6acq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/465243/original/file-20220525-12-1j6acq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/465243/original/file-20220525-12-1j6acq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/465243/original/file-20220525-12-1j6acq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We studied adaptive evolution in several species, including the superb fairy-wren, hihi, song sparrow, blue tit, rhesus macaque, yellow baboon, snow vole and spotted hyena.</span>
<span class="attribution"><span class="source">Timothée Bonnet, Geoff Beals, Pirmin Nietlisbach, Ashley Latimer, Lauren Brent, Fernando Campos, Oliver Höner</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We worked with 27 research institutions to assemble data from 19 wild populations that have been monitored for long periods of time, some since the 1950s. Generations of researchers collected information about the birth, mating, reproduction and death of each individual in these populations.</p>
<p>Together, those data represent around 250,000 animals and 2.6 million hours of field work. The investment may look outrageous, but the data have already been used in thousands of scientific studies and will be used again.</p>
<h2>Statistics to the rescue</h2>
<p>We then used quantitative genetic models to apply the “fundamental theorem” to each population. Instead of keeping track of changes in every gene, quantitative genetics uses statistics to capture the net effect emerging from changes in thousands of genes. </p>
<p>We also developed a new statistical method that fits the data better than previous models. Our method captures two key properties of how survival and reproduction are unevenly distributed across populations in the wild. </p>
<p>First, most individuals die before breeding, meaning there are a lot of entries in the “zero offspring” column of the lifetime reproduction record.</p>
<p>Second, whereas most breeders have only a few offspring, some have a disproportionately high number, leading to an asymmetric distribution. </p>
<h2>The rate of evolution</h2>
<p>Among our 19 populations, we found that, on average, genetic change in response to selection was responsible for an 18.5% increase per generation in the ability of individuals to survive and reproduce. </p>
<p>This means offspring are on average 18.5% “better” than their parents. To put it another way, an average population could survive an 18.5% deterioration in the quality of its environment. (This may change if genetic response to selection is not the only force at play; more on that below.) </p>
<p>Given these rates, we found adaptive evolution could explain most recent changes in wild animal traits (such as size or reproductive timing). Other mechanisms are important too, but this is strong evidence evolution should be considered alongside other explanations. </p>
<h2>An exciting result for an uncertain future</h2>
<p>What does this mean for the future? At a time when natural environments are changing dramatically all over the world, due to climate change and other forces, will evolution help animals adapt?</p>
<p>Unfortunately, that is where things get tricky. Our research estimated only genetic changes due to natural selection, but in the context of climate change there are other forces at play. </p>
<p>First, there are other evolutionary forces (such as mutations, random chance and migration). </p>
<p>Second, the environmental change itself is likely a more important driver of population demographics than genetic change. If the environment keeps deteriorating, theory tells us that adaptive evolution will generally be unable to fully compensate. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/life-quickly-finds-a-way-the-surprisingly-swift-end-to-evolutions-big-bang-110984">Life quickly finds a way: the surprisingly swift end to evolution's big bang</a>
</strong>
</em>
</p>
<hr>
<p>Finally, adaptive evolution can itself change the environment experienced by future generations. In particular, when individuals compete with each other for a resource (such as food, territory or mates), any genetic improvement will lead to more competition in the population.</p>
<p>Our work alone is insufficient to draw predictions. However, it shows that evolution cannot be discounted if we want to accurately predict the near future of animal populations. </p>
<p>Despite the practical challenges, we are thrilled to witness Darwinian evolution, a process once thought exceedingly slow, acting observably in our lifetimes.</p><img src="https://counter.theconversation.com/content/183633/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Timothée Bonnet receives funding from Australian Research Council. </span></em></p>A long-term study of wild animal populations shows each generation is on average almost 20% genetically ‘better’ than their parents at surviving and reproducing.Timothée Bonnet, Researcher in evolutionary biology (DECRA fellow), Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1708802022-02-07T02:14:30Z2022-02-07T02:14:30Z150 years ago, Charles Darwin wrote about how expressions evolved – pre-empting modern psychology by a century<figure><img src="https://images.theconversation.com/files/444689/original/file-20220207-23-1hozj3x.jpg?ixlib=rb-1.1.0&rect=0%2C44%2C5991%2C2946&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/The_Expression_of_the_Emotions_in_Man_and_Animals">The Expression of the Emotions in Man and Animals / Wikimedia</a></span></figcaption></figure><p>Was Charles Darwin a one-hit wonder? According to scientists who take a gene’s-eye view of evolution, the 19th-century English naturalist contributed one crucial idea to understanding how species change: natural selection, or “design without a designer”. </p>
<p>However, a book of Darwin’s that is little read by modern evolutionists – The Expression of the Emotions in Man and Animals – turns out to contain valuable lessons for scientists seeking to understand how and why humans do what we do.</p>
<p>Published 150 years ago, the book has long bemused scientific readers because it hardly mentions natural selection. Instead, it puts how organisms behave at the heart of evolutionary adaptation – an idea that is becoming commonplace in 21st-century biology.</p>
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Read more:
<a href="https://theconversation.com/curious-kids-how-do-scientists-know-evolution-is-real-122039">Curious Kids: how do scientists know evolution is real?</a>
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<h2>Putting agency into evolution</h2>
<p>Since the 1940s, evolutionists have viewed natural selection as an aimless mechanism: random genetic variations arise, and chance environmental events allow the most beneficial (or “fittest”) ones to survive. </p>
<p>More recently, biologists have found it necessary to introduce <a href="https://doi.org/10.1017/CBO9781316402719">the actual behaviour of living creatures</a> into this picture. From this perspective, organisms adapt to their circumstances, and genetics then stabilises the changes.</p>
<p>As I show in my book <a href="https://global.oup.com/academic/product/darwins-psychology-9780198708216?cc=au&lang=en&">Darwin’s Psychology</a>, for Darwin, the agency of organisms – their ability to <em>do</em> things – was the key, whether in driving the struggle for existence, or in explaining the antics of climbing plants, babies and earthworms. </p>
<p>This was because actions produce reactions: what a creature does has consequences for itself and its surroundings. </p>
<p>Those consequences shape its own subsequent actions, <em>and</em> how its descendants eventually evolve. </p>
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Read more:
<a href="https://theconversation.com/social-plants-in-the-wild-staghorn-ferns-grow-in-colonies-to-improve-water-storage-for-all-members-156377">Social plants: in the wild, staghorn ferns grow in colonies to improve water storage for all members</a>
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<p>Some consequences prove injurious or fatal. Others enhance the doer’s life, even if it is in ways that are not immediately obvious, such as <a href="https://theconversation.com/how-trees-communicate-via-a-wood-wide-web-65368">forest trees</a> and honeybees who render “mutual aid” to other members of their own species.</p>
<p>Darwin took this view of agency and applied it to what he called the most social of social species, ourselves. </p>
<h2>Expressions and meaning</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=567&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=567&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=567&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=713&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=713&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444686/original/file-20220206-25-8dnci5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=713&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Darwin studied the mechanics of facial expressions in great detail.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/The_Expression_of_the_Emotions_in_Man_and_Animals#/media/File:Expression_of_the_Emotions_Figure_1.png">The Expression of the Emotions in Man and Animals / Wikimedia</a></span>
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<p>He analysed in great detail more than 70 different components and types of facial expressions plus other non-facial gestures. </p>
<p>Darwin concluded the movements we call expressions, such as smiling and crying, did not evolve to communicate. For Darwin, smiles and tears do not arrive at the body’s surface already steeped in emotional meanings brewed in the hidden recesses of the expresser’s mind. They are accidental side-effects of other “habits”, or of the ways the nervous system works. </p>
<p>“Expressions” only become meaningful when others read them as such, so the meaning of any so-called “emotional expression” depends on context and other people.</p>
<p>Viewed this way, Darwin’s book argues an expression could only ever have evolved or “become instinctive” if the ability to recognise it had also evolved and “likewise become instinctive”. And if recognising expressions is instinctive, Darwin reasoned, humans should be born able to understand gestures and facial displays. </p>
<h2>Child’s play</h2>
<p>To find out whether this was the case, Darwin carefully studied the social behaviour of his firstborn child, Doddy. He observed Doddy understood, “at a very early period, the meaning or feelings” of those who took care of him, “by the expression of their features”. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/444693/original/file-20220207-15-xwwiyq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444693/original/file-20220207-15-xwwiyq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444693/original/file-20220207-15-xwwiyq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444693/original/file-20220207-15-xwwiyq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444693/original/file-20220207-15-xwwiyq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444693/original/file-20220207-15-xwwiyq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444693/original/file-20220207-15-xwwiyq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Recent research has confirmed Darwin’s theory that even very young babies can interpret the expressions of others.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Darwin tells us he aimed many “odd noises and strange grimaces” at his four-month-old son. These did not scare Doddy, however, being “taken as good jokes”, because they were “preceded or accompanied by smiles” – the smiles proving legible to Doddy as making humorous his father’s otherwise-fearsome growling and gurning. </p>
<p>These observations pre-empted by more than a century modern psychology’s discovery <a href="https://www.researchgate.net/profile/Colwyn-Trevarthen/publication/12124855_Infant_Intersubjectivity_Research_Theory_and_Clinical_Applications/links/5eb14ef9a6fdcc7050a99ced/Infant-Intersubjectivity-Research-Theory-and-Clinical-Applications.pdf">babies have an inbuilt capacity for sympathetic mind-reading and mental sharing</a>.</p>
<h2>Universal emotions?</h2>
<p>Darwin made clear his book presented a theory of <em>expression</em> rather than a theory of emotion. While he painstakingly pioneered a modern physiological way of studying the human movements it discusses, he found the meanings of such movements – whether emotional or not – to be inescapably social. </p>
<p><a href="https://www.researchgate.net/profile/Alan-Costall/publication/223660643_Rethinking_the_Development_of_Nonbasic_Emotions_A_Critical_Review_of_Existing_Theories/links/60e17356299bf1ea9ede1bc9/Rethinking-the-Development-of-Nonbasic-Emotions-A-Critical-Review-of-Existing-Theories.pdf">Modern psychologists argue</a> over a split between supposedly “basic”, “biological” or “universal” emotions such as anger, which are held to be directly linked to one’s physical state, and “social” emotions such as envy, which are supposed to result from our readings of others. </p>
<p>Darwin’s work sidesteps this controversy, arguing only the observable patterns of facial action we call “expressions” can ever be universal. Whatever meanings are attributed to those actions must derive from the social relationships they reflect.</p>
<h2>Reading faces</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=830&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=830&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=830&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1043&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1043&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444687/original/file-20220206-19-4b8osy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1043&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Darwin used the experiments of the neurologist Guillaume Duchenne, who used electrical stimulation of face muscles to produce expressions.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Duchenne_de_Boulogne#/media/File:Guillaume_Duchenne_de_Boulogne_performing_facial_electrostimulus_experiments.jpg">Wikimedia</a></span>
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<p>In Darwin’s time, the traditional way of studying emotions was to ask people about why they were smiling or what they were angry about. However, Darwin’s research went the opposite way: he asked people about how they understood the expressions of others. </p>
<p>He asked expatriate Europeans living on six continents to fill in a survey about the forms of expressive movement they had seen in diverse indigenous peoples “who have associated but little with Europeans”. </p>
<p>He also asked 20 or so well-educated members of his circle to judge what meanings they saw in photographs of 11 facial displays neurologist Guillaume Duchenne had produced by attaching electrodes to muscles in the faces of volunteers so as to simulate different emotional expressions. </p>
<p>Darwin held that only photographs which judges agreed about could be called “genuine” expressions. Pictures of terror, sorrow or laughter produced unanimous responses. Other photos, including Duchenne’s portrait of hatred, proved indecipherable.</p>
<h2>Blushing</h2>
<p>The masterstroke of The Expression of the Emotions in Man and Animals comes in its longest chapter, on blushing. Blushes, Darwin shows, result from the <em>rebounding</em> of our faculty for reading others: it is “the thinking what others think of us which excites a blush”. </p>
<p>Thus blushers will blush when they imagine someone blames them for something, even when they are innocent. This conclusion, that one’s reading of others’ attitudes shapes how one acts, underpins the treatments of conscience and morality, sexual coquetry and culture which fill Darwin’s earlier book The Descent of Man (1871). </p>
<p>It also inspired social theorist George Herbert Mead’s invention of what sociologists now call “<a href="https://en.wikipedia.org/wiki/Symbolic_interactionism">symbolic interactionism</a>” – the view that all human actions are shaped by what they signify in the groups where they occur.</p>
<p>Read alongside The Descent of Man, of which it was at first intended to form part, The Expression of the Emotions proves that Darwin’s vision of nature as a theatre of agency did more than anticipate biology’s newest theory of adaptation. That same vision laid the groundwork for an idea of psychology based in evolution, where all human meaning has a social origin.</p>
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Read more:
<a href="https://theconversation.com/guide-to-the-classics-darwins-the-descent-of-man-150-years-on-sex-race-and-our-lowly-ape-ancestry-155305">Guide to the classics: Darwin's The Descent of Man 150 years on — sex, race and our 'lowly' ape ancestry</a>
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<img src="https://counter.theconversation.com/content/170880/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ben Bradley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In 1872, Charles Darwin published a book on expressions and emotions that modern science is only beginning to catch up with.Ben Bradley, Professor Emeritus (Psychology), Charles Sturt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1747372022-02-03T14:27:07Z2022-02-03T14:27:07ZFig wasp sex ratios show that not all of nature is by design<figure><img src="https://images.theconversation.com/files/440616/original/file-20220113-19-1c80d6.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A female pollinating wasp, _Platyscapa awekei_, which pollinates the Wonderboom fig, a famous fig tree in South Africa.</span> <span class="attribution"><span class="source">Simon van Noort</span></span></figcaption></figure><p>In his 1859 book, <a href="https://www.britannica.com/biography/Charles-Darwin/On-the-Origin-of-Species">On the Origin of Species</a>, British naturalist Charles Darwin put forward his theory of natural selection. This, he argued, was the mechanism of biological evolution: like an animal or plant breeder selects for certain characteristics, individuals with better survival ability leave more offspring. In this way nature favours traits that increase the survival of organisms. These traits are called adaptations. For instance the internal structure of an eye, comprising a lens and a light-sensitive retina, leaves little doubt that the organ is an adaptation for vision. When viewed from outside science, adaptations appear to have been designed. </p>
<p>However, animals and plants often have characteristics perceived as advantageous, but for which there is no evidence of evolutionary adaptation. The red colour of blood has some advantages – it allows humans to rapidly notice and react to injuries – but there’s no evidence that the colour is an adaptation or has been designed. Rather it is the fortuitous biochemical consequence of an iron molecule bound to each haemoglobin molecule in the blood.</p>
<p>Assuming that natural selection shapes all animal and plant traits is a false impression. Natural selection is <a href="https://evolution-outreach.biomedcentral.com/articles/10.1186/s12052-020-00130-y">not all-encompassing</a>.
Since humans are largely predisposed to see purpose and design, it may be hard to understand traits that appear to have been designed, but which just came about by chance. In a <a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00447-4">recent article</a>, we showed that what seemed to be an example of adaptation – variation in female-biased sex-ratios of fig wasps – is in fact not.</p>
<h2>Imperfection in nature</h2>
<p>Fig wasps are tiny insects (about 2mm long) that <a href="http://figweb.org/Interaction/index.htm">pollinate fig trees</a>. Fig wasp sex ratios have been touted as one of <a href="https://era.ed.ac.uk/bitstream/handle/1842/480/WestHerreSheldon00.PDF?sequence=1&isAllowed=y">the best examples</a> of natural selection’s effectiveness. Only one or a few mothers lay eggs in a single fig, in which mating between offspring also takes place. When only one mother occupies a fig, about 10% of her offspring are sons. In line with predictions, when more mothers lay their eggs in a fig, they lay a larger percentage of sons to use the mating opportunities provided by the daughters of other mothers. By varying the percentage of sons the mothers’ number of grandchildren can be maximised. </p>
<p><a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00447-4">Our research</a> debunks this notion. We reviewed sex ratios in 24 species of fig wasps and found that mothers sharing a fig with other mothers laid fewer sons than would be expected if this were an adaptation. Although the ratio of sons to daughters increases with the number of mothers, as theory suggests, the increase is significantly smaller than predicted.</p>
<p>This sort of work is important as it reminds scientists that apparent adaptations may merely be fortuitous consequences. It is a reminder that sometimes there is no point or evolutionary purpose of animal characteristics, even when it looks that way – natural selection is not the only process that changes species. </p>
<h2>Sex ratios in single mother broods</h2>
<p>Some species, resistant to the ill effects of inbreeding, have very female-biased sex-ratios. The British evolutionary theorist William Hamilton argued in 1967 that this is expected when one or a few mothers of a species such as wasps lay eggs in isolated patches and matings among offspring are restricted to within these patches. </p>
<p>Changing the sex ratio of offspring does not affect a mother’s number of offspring; it does, however, change her expected number of grandchildren. By laying more daughter eggs rather than son eggs, the competition between brothers is reduced and there are more mating opportunities for the remaining sons. Since a single son can fertilise many daughters, selection favours a mother that lays just a sufficient number of male eggs to fertilise all her daughters – a heavily female-biased sex-ratio. Fig wasps represent one such group of species.</p>
<h2>Broods involving several mothers</h2>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/17815055/">Research</a> in the 1980s <a href="https://pubmed.ncbi.nlm.nih.gov/28561492/">established</a> that single mothers in a patch have more daughters than each mother in a patch with two mothers, who in turn have more daughters than each mother in a patch with three mothers. Even though they have fewer daughters, they still have more daughters than sons. The theoretical benefit of the reduction in female bias stems from the mother’s sons competing less with each other and more with other males, and from a son benefiting from fertilising other females’ many daughters. </p>
<p><a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00447-4">We reviewed</a> sex ratios in 24 fig wasp species that have been studied. We found that although the ratio of sons to daughters increased with the number of mothers in each fig, as theory suggests, the increase was significantly smaller than predicted.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/442217/original/file-20220124-15-7vo28w.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442217/original/file-20220124-15-7vo28w.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=518&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442217/original/file-20220124-15-7vo28w.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=518&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442217/original/file-20220124-15-7vo28w.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=518&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442217/original/file-20220124-15-7vo28w.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=651&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442217/original/file-20220124-15-7vo28w.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=651&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442217/original/file-20220124-15-7vo28w.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=651&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The percentage of sons given a certain number of mothers in a fig. Model predictions in black and the observed percentages in red. The circle, square and triangle distinguish three species.</span>
<span class="attribution"><a class="source" href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00447-4">From https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00447-4</a></span>
</figcaption>
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<p>Mother fig wasps tend to lay most of their sons first, followed by mostly daughters. In wasps unfertilised eggs develop into males and fertilised eggs into daughters. When there are several mothers in a single fig, egg-laying sites (the small flowers inside a fig) become limited and mothers cannot lay all their eggs. Since these unlaid eggs would have been daughter eggs, the ratio of sons to daughters increases automatically.</p>
<p>Since these unlaid eggs would have been daughter eggs, the ratio of sons to daughters increases automatically. In about half the studied fig wasp species this mechanism is sufficient to explain skewed sex ratios in these wasps. In the other half of the studied fig wasp species, mothers actually increase the number of sons as if they sense other mothers. However, despite this change, there are still fewer sons per daughter as compared to theory involving adaptation.</p>
<p>So although natural selection could favour the observed shift in sex ratios, there is no evidence that it is the result of natural selection. This is a good example of a trait that appears to be adaptive, but is not. Our review suggests that even apparently “designed” traits may not be the result of natural selection – instead they may be be fortuitously advantageous consequences.</p><img src="https://counter.theconversation.com/content/174737/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jaco Greeff received funding from the National Research Foundation to study sex ratios.</span></em></p><p class="fine-print"><em><span>Jan Willem Helenus Ferguson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Assuming that natural selection shapes all animal and plant traits is a false impression. Natural selection is a mindless process.Jaco Greeff, Professor in Genetics, University of PretoriaJan Willem Helenus Ferguson, Emeritus Professor, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1752612022-01-20T19:10:37Z2022-01-20T19:10:37ZEvolution: how Victorian sexism influenced Darwin’s theories – new research<figure><img src="https://images.theconversation.com/files/441621/original/file-20220119-27-1fxdbtg.jpg?ixlib=rb-1.1.0&rect=22%2C31%2C2973%2C1962&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Peacocking isn't the only way to attract mates.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/peacock-tail-elegant-colourful-portrait-1776577028">Andrey Bocharov/Shutterstock</a></span></figcaption></figure><p>Sex is an expensive business, biologically speaking. Finding a suitable mate takes time and energy. Offspring are also a huge investment of resources. But sex does offer a rewarding possibility: children who are fitter than their parents thanks to new and “better” combinations of genes. Darwin realised that many animal species therefore carefully select their mates.</p>
<p>There is an innate biological inequality, however. Eggs are relatively few in number – a large and costly investment – while sperm are small and vastly more abundant. And embryos often need further investment in the body or outside. Since the greater investment tends to fall on females, they are often the more selective sex (while males compete to be chosen).</p>
<p>But according to a new paper, <a href="http://www.science.org/doi/10.1126/science.abi6308">published in Science</a>, Charles Darwin’s patriarchal world view led him to dismiss female agency and mate choice in humans. </p>
<p>He also downplayed the role of female variation in other animal species, assuming they were rather uniform, and always made similar decisions. And he thought there was enormous variation among the males who battled for female attention by showing off stunning ranges of skills and beauty. This maintained the focus on the dynamics of male dominance hierarchies, sexual ornamentation and variation as drivers of sexual selection, even if females sometimes did the choosing.</p>
<p>But do Darwin’s ideas on sexual selection hold up today?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441742/original/file-20220120-9679-13ap1iy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Male ringed pipefish carry the eggs until they hatch.</span>
<span class="attribution"><span class="source">François Libert/flickr</span></span>
</figcaption>
</figure>
<h2>Complex choices</h2>
<p>When animals choose a partner, their appearance, sound and smell can all be accurate guides to the survival ability of the prospective mate. For example, large antlers in deer are a good indicator of fighting ability, dominance and overall fitness. But many other traits can be chosen because they are otherwise conspicuous and attractive yet may be a poor guide to overall genetic quality, or even misleading. </p>
<p>Females may evolve to choose mates with whom <a href="https://www.jstor.org/stable/2460199">their offspring are less likely to survive</a>, provided there are more such offspring as a trade off. In some species of poecilid fish, for example, male attractiveness is linked to genes that can reduce their survival. Females therefore face a dilemma: mate with a more attractive male and produce some highly attractive but otherwise less vigorous sons, or mate with a less attractive male to maximise the survival of those sons. Which strategy will produce most grandchildren?</p>
<p>Females may therefore select for traits in males that apparently have no other bearing upon their ability to survive. The peacock’s tail is a handicap in most other aspects of its life – an impediment to flight and evading predators – save for the attraction of a female. However, it may also be true that the ability of a male to manage such a burden <a href="https://www.sciencedirect.com/science/article/abs/pii/0022519375901113">is itself a marker</a> of overall genetic quality and rigour. </p>
<figure class="align-center ">
<img alt="Image of a statue of Charles Darwin, Natural History Museum. London." src="https://images.theconversation.com/files/441518/original/file-20220119-23-1usparh.jpg?ixlib=rb-1.1.0&rect=40%2C5%2C3908%2C2796&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441518/original/file-20220119-23-1usparh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=434&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441518/original/file-20220119-23-1usparh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=434&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441518/original/file-20220119-23-1usparh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=434&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441518/original/file-20220119-23-1usparh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=545&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441518/original/file-20220119-23-1usparh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=545&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441518/original/file-20220119-23-1usparh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=545&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Darwin, Natural History Museum. London.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/statue-charles-darwin-natural-history-museum-78485386">Shutterstock</a></span>
</figcaption>
</figure>
<p>It isn’t always females who choose. In pipefishes, the males invest heavily by carrying the fertilised eggs until they hatch, and it is the females who compete with each other in order to secure the attentions of males. </p>
<p>Optimal mate choice is not the same for all individuals, or at all times in their development. For example, younger satin bowerbirds are frightened by the most vigorous male displays, while older females typically find these most attractive. And many fishes are sequential hermaphrodites, changing sex – and therefore mate choices – as they age. </p>
<p>Research since Darwin therefore reveals that mate choice is a far more complex process than he may have supposed, and is governed by variation in both sexes. </p>
<h2>Was Darwin a sexist?</h2>
<p>So, is the accusation of sexism levelled at Darwin really valid, and did this cloud his science? There is certainly some evidence that Darwin underestimated the importance of variation, strategy and even promiscuity in most female animals. </p>
<p>For example, Darwin - possibly as a result of a prevailing prudishness - placed little emphasis on mechanisms of sexual selection that operate <em>after</em> mating. Female birds and mammals may choose to mate with multiple males, and their sperm can compete to fertilise one or more eggs within the reproductive tract. </p>
<p>Cats, dogs and other animals can have litters with multiple fathers (the gloriously named “<a href="https://www.theguardian.com/lifeandstyle/shortcuts/2018/dec/11/one-set-twins-two-fathers-how-common-is-superfecundation">heteropaternal superfecundation</a>” - even though the sound of it is really quite atrocious!). There is even some suggestion that the human penis – being thicker than our nearest primate relatives – is an adaptation for <a href="http://news.bbc.co.uk/1/hi/health/3128753.stm">physically displacing the sperm of competing males</a>. Such earthy speculations were anathema to Darwin’s sensibilities.</p>
<p>Female blue tits <a href="https://www.sciencedaily.com/releases/2016/05/160530101136.htm">often mate with multiple males</a> in order to ensure their protection and support - a somewhat manipulative strategy when paternity for the prospective fathers is uncertain. All this challenges Darwin’s assumption that females are relatively passive and non-strategic. </p>
<p>Where males make a greater investment, they become more active in mate choice. Male (rather than female) poison dart frogs (<em>Dendrobates auratus</em>) protect the young, and therefore attract multiple females who compete to lay eggs for them to fertilise. Many bird species have biparental care, and therefore a richer diversity of mating systems.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Image of a poison dart frog." src="https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=322&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=322&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=322&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=404&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=404&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441630/original/file-20220119-15-1snjkj7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=404&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dendrobates auratus, a poison dart frog.</span>
<span class="attribution"><span class="source">Brian Gratwicke/flickr</span></span>
</figcaption>
</figure>
<p>Inevitably, Darwin’s world view was shaped by the culture of his time, and his personal writings make it difficult to mount a particularly robust defence. <a href="https://www.darwinproject.ac.uk/letter/DCP-LETT-13607.xml">In a letter from 1882, he wrote</a> “I certainly think that women, though generally superior to men to [sic] moral qualities are inferior intellectually; & there seems to me to be a great difficulty from the laws of inheritance … in their becoming the intellectual equals of man”. </p>
<p>He also deliberated over the relative merits of marriage, <a href="https://www.darwinproject.ac.uk/tags/about-darwin/family-life/darwin-marriage#">famously noting</a>: “Home, & someone to take care of house — Charms of music & female chit-chat. — These things good for one’s health. — but terrible loss of time”.</p>
<p>Unsurprisingly there is much that Darwin did not fully understand. Darwin – like Albert Einstein, H.G. Wells and Edgar Allan Poe – married his first cousin, Emma Wedgwood. Ironically, he knew nothing of genetics and the mechanisms by which close relatives are more likely to have offspring with certain genetic diseases. Intriguingly, our closest relatives in the tree of life, the chimpanzees, <a href="https://today.duke.edu/2017/01/genetic-opposites-attract-when-chimpanzees-choose-mate">naturally circumvent this problem</a>, since females select mates that are more distantly related to them than the average male in the available pool. </p>
<figure class="align-center ">
<img alt="Image of chimpanzees." src="https://images.theconversation.com/files/441517/original/file-20220119-25-1j6mbia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441517/original/file-20220119-25-1j6mbia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441517/original/file-20220119-25-1j6mbia.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441517/original/file-20220119-25-1j6mbia.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441517/original/file-20220119-25-1j6mbia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441517/original/file-20220119-25-1j6mbia.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441517/original/file-20220119-25-1j6mbia.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Female chimpanzees make good choices.</span>
<span class="attribution"><a class="source" href="https://pixahive.com/photo/monkey-13/">Phenix/PixaHive</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Despite its omissions, however, Darwin’s understanding was <a href="https://www.youtube.com/watch?v=s5P4uYsK8_c&t=13s">radically more advanced than anything that preceded it</a>. When combined with the subsequent understanding of genetics and inheritance, Darwin’s writings are still the bedrock of all modern evolutionary biology.</p><img src="https://counter.theconversation.com/content/175261/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Wills receives funding from the John Templeton Foundation (Grant ID 61408). </span></em></p>Darwin thought female animals were non-strategic and uniform, making similar decisions.Matthew Wills, Professor of Evolutionary Palaeobiology at the Milner Centre for Evolution, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1747522022-01-12T13:38:21Z2022-01-12T13:38:21ZFive fascinating insights into the inner lives of plants<figure><img src="https://images.theconversation.com/files/440454/original/file-20220112-25-zmd311.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C7289%2C4772&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-plant-growing-sunlight-609086588">Romolo Tavani/Shutterstock</a></span></figcaption></figure><p>Approximately 4.5 billion years ago, Earth’s land surface was barren and devoid of life. It would take another 2 billion years for the first single-celled organisms to appear in the ocean, including the first algae <em><a href="http://www.jsjgeology.net/Grypania-spiralis.htm">Grypania spiralis</a></em>, which was about the size of a 50 pence piece.</p>
<p>Plants composed of many cells have only been around for a mere 800 million years. To survive on land, plants had to protect themselves from UV radiation and develop spores and later seeds which allowed them to disperse more widely. These innovations helped plants become one of the most influential lifeforms on Earth. Today, plants are found in every major ecosystem on the planet and scientists describe more than 2,000 new species every year.</p>
<p>David Attenborough’s new documentary <a href="https://www.bbc.co.uk/programmes/m0013cl7">The Green Planet</a> casts the spotlight on plants and their ability to inspire us. In just one recent example, engineers have successfully mimicked the shape of winged maple seeds <a href="https://www.semanticscholar.org/paper/Maple-Seed-Performance-as-a-Wind-Turbine-Holden-Caley/4f5e2060500f2cd06ab63bbdf74024fdbf0c0f16">to design</a> new wind turbines.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/BoKyMzsa4Xs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Plants retain many secrets which scientists have yet to discover. But here are five discoveries which helped us see our distant green cousins in a new light.</p>
<h2>1. Plants ‘talk’ to each other</h2>
<p>Of course, plants do not possess vocal cords and so cannot talk like we do. But they do use chemical and electronic signals to coordinate responses to their environment.</p>
<p>When plant cells are damaged, like grass cut by a lawnmower, they release protein fragments which can be detected by surrounding plants. It’s like a neighbourhood watch system: when one plant is harmed, the others are notified that there is danger nearby. This can trigger an immune response or other defences.</p>
<p>Similarly, plants can detect pollinators in their vicinity and release chemicals to attract them. These signals make plants very complex communicators.</p>
<figure class="align-center ">
<img alt="A tropical flowering plant covered in large, green ants." src="https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/440452/original/file-20220112-21-ughdth.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Plants can attract insects to do their bidding.</span>
<span class="attribution"><span class="source">Thom Dallimore</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>2. Plants can move</h2>
<p>In his seminal book <a href="https://www.cambridge.org/core/books/power-of-movement-in-plants/9B9B104AB3638E43936A34F1FB73E393">The Power of Movement in Plants</a>, published in 1880, Charles Darwin described the ability of plants to move away or towards light. Scientists call this phototropism. Plant movements are now known to not only be guided by light, but also water, nutrients and in response to grazing by animals and competition from other plants. </p>
<p>Plants may appear frozen in place, destined to remain where their seeds germinate. But in fact, plants constantly adjust their leaves, roots and stems to improve their chances of survival. For example, the shaded sides of stems always grow longer to ensure the plant grows towards light in a process mediated by hormones. Roots show the opposite effect, causing them to grow away from the light. </p>
<p>In some extreme cases, plants can even move across an entire forest. Nomadic vines grow upwards from the bottom of a tree trunk then detach from the soil. Later, they put down aerial roots and descend again, allowing them to <a href="https://www.jstor.org/stable/2261006?seq=1#metadata_info_tab_contents">move between trees</a>.</p>
<h2>3. Plants can grow in outer space</h2>
<p>The idea of traversing space and living on other planets has long excited the human imagination. But no planets with the same environment as Earth have been found. We know plants are experts at modifying environments to suit the needs of more complex life. As early forests began photosynthesising, they oxygenated Earth’s atmosphere and drew down CO₂, making the planet more hospitable.</p>
<p>Could growing plants on distant planets make them more suitable to our needs? During the space race between the USSR and the US in the 1950s and 1960s, scientists studied how plants grow and develop in space. So far, scientists have grown 17 different species of plants in specialised chambers, including crops like <a href="https://www.nasa.gov/feature/nasa-astronaut-paints-a-picture-of-success-growing-plants-in-space">corn, wheat, tomatoes and lettuce</a>. Big challenges to growing Earth’s plants outside our atmosphere remain, including radiation during space flight and differences in gas movements in space compared to Earth. If you think it’s hard to keep a plant alive at home, try doing it in space.</p>
<p>The ability to terraform a planet – making it suitable for humans to live on – remains elusive. But major progress in plant science over the last few years make this an achievable target, perhaps within the lifetime of people alive today.</p>
<h2>4. One in ten plants grow on other plants</h2>
<p>Often towering tens of metres tall are some of the largest organisms on the planet. Redwood trees, for example, can grow over 100 metres tall. Scientists first began studying their lofty forest canopies by training monkeys or employing skilled climbers to collect samples. Some even used shotguns to shoot down samples. </p>
<p>It was not until the 1980s that canopy research became a scientific discipline in its own right, with the use of rope climbing techniques borrowed from mountaineering. Later, cranes, balloons and drones joined the toolset of many scientists. But why risk your life to climb a tree? What’s up there? </p>
<p>It’s estimated that up to <a href="https://www.sciencedirect.com/science/article/pii/S0169534717300599">80% of species</a> in a forest either use or live their entire lives in the forest canopy. One in ten of all known species of vascular plants – species which use vein-like vessels to transport water and nutrients throughout their body – grow on top of other plants. </p>
<figure class="align-center ">
<img alt="A tree whose bark is concealed by green and fuzzy plants growing on its surface." src="https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/440453/original/file-20220112-21-1khse3w.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A tree in Papua New Guinea covered in epiphytic ferns and orchids.</span>
<span class="attribution"><span class="source">Thom Dallimore</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These are called epiphytes. They are not parasites, but instead use their host for physical support. This gives them an advantage over plants growing in the forest understorey, where light is scarce. Most orchids grow on trees and a single tree can hold as many as 50 species of epiphyte. Often, these epiphytes put out more leaves than their host tree. </p>
<h2>5. Plants can indicate global change</h2>
<p>Organisms are very sensitive to changes in their environment and plants in particular have been used to detect these changes for centuries. When leaves start to change colour in autumn, it usually heralds the arrival of cooler and darker months. </p>
<p>Certain species of ferns are particularly vulnerable to changes in their local climate. Filmy ferns grow in shaded regions of tropical forests, usually near the bases of trees or on wet rocks. They rely on water and low temperatures, and are good indicators of oncoming drought and rising temperatures.</p>
<p>Since the 1980s, the global average temperature has been rising as a direct result of burning fossil fuels like coal, which was deposited by plants millions of years ago during the early formation of forests. We are living in a time of change and understanding how plants respond to changes in climate can help us to prepare ourselves for the future.</p><img src="https://counter.theconversation.com/content/174752/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sven Batke does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>David Attenborough’s new BBC documentary The Green Planet shows plants are stranger than they first appear.Sven Batke, Lecturer in Biology, Edge Hill UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1689252021-11-23T13:30:15Z2021-11-23T13:30:15ZArt illuminates the beauty of science – and could inspire the next generation of scientists young and old<figure><img src="https://images.theconversation.com/files/432929/original/file-20211119-17-ptux52.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4962%2C5816&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The annual BioArt competition highlights the hidden parts of biology revealed under a microscope.</span> <span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/green.png">Todd Green/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Scientists have often invited the public to see what they see, using everything from <a href="https://www.latimes.com/science/sciencenow/la-sci-sn-cell-printing-chinese-woodblock-inkjet-20140210-story.html">engraved woodblocks</a> to <a href="https://www.smithsonianmag.com/science-nature/science-images-that-border-on-art-50661407/">electron microscopes</a> to explore the complexity of the scientific enterprise and the beauty of life. <a href="https://doi.org/10.1038/d41586-019-03306-9">Sharing these visions</a> through illustrations, photography and videos has allowed laypeople to explore a range of discoveries, from new bird species to the inner workings of the human cell.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Micrograph of mouse intestinal villi." src="https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1352&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1352&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1352&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1699&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1699&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1699&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A winner of the 2018 BioArt contest, this image shows the intestinal villi of a mouse.</span>
<span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2018BioArtWinners/2018BioArtWinners-09.jpg">Amy Engevik/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>As a <a href="https://www.researchgate.net/profile/Christine-Curran">neuroscience and bioscience researcher</a>, I know that scientists are sometimes pigeonholed as white lab coats obsessed with charts and graphs. What that stereotype misses is their passion for science as a mode of discovery. That’s why scientists frequently turn to <a href="https://www.cnn.com/style/article/bio-art-microbes-and-machines/index.html">awe-inducing visualizations</a> as a way to explain the unexplainable.</p>
<p>The <a href="https://faseb.org/partnerships-and-outreach/bioart">BioArt Scientific Image and Video Competition</a>, administered by the <a href="https://www.faseb.org/">Federation of American Societies for Experimental Biology</a>, shares images rarely seen outside the laboratory with the public in order to introduce and educate laypeople about the wonder often associated with biological research. BioArt and similar contests reflect the lengthy history of using imagery to elucidate science. </p>
<h2>A historical and intellectual moment</h2>
<p>The <a href="https://www.livescience.com/55230-renaissance.html">Renaissance</a>, a period in European history between the 14th and 17th centuries, breathed new life into both science and art. It brought together the fledgling discipline of <a href="https://www.encyclopedia.com/history/modern-europe/ancient-history-middle-ages-and-feudalism/natural-history">natural history</a> – a field of inquiry observing animals, plants and fungi in their ordinary environments – with artistic illustration. This allowed for wider study and classification of the natural world.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Peter Paul Ruben's 'Anatomical Studies: a left forearm in two positions and a right forearm'" src="https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=865&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=865&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=865&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1086&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1086&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1086&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Art played a role in advancing the natural sciences in the Renaissance period, such as Rubens’ human anatomical studies.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Anatomical_Studies-_a_left_forearm_in_two_positions_and_a_right_forearm_MET_DT3993.jpg">Peter Paul Rubens/The Metropolitan Museum of Art via Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Artists and artistic naturalists were also able to advance approaches to the study of nature by illustrating discoveries of early botanists and anatomists. Flemish artist Peter Paul Rubens, for example, offered remarkable insight into human anatomy in his <a href="https://www.illustrationhistory.org/essays/the-drawing-methods-and-techniques-of-peter-paul-rubens">famous anatomical drawings</a>.</p>
<p>This art-science formula was further democratized in the 17th and 18th centuries as the <a href="https://www.metmuseum.org/toah/hd/prnt/hd_prnt.htm">printing process became more sophisticated</a> and allowed early ornithologists and anatomists to publish and disseminate their elegant drawings. Initial popular entries included John James Audubon’s
“<a href="https://www.outsideonline.com/outdoor-adventure/environment/plaid-and-canvas-audubons-birds-america/">Birds of America</a>” and Charles Darwin’s “<a href="https://www.smithsonianmag.com/science-nature/beautiful-drawings-darwins-artist-residence-180954953/">The Origin of the Species</a>” – groundbreaking at the time for the clarity of their illustrations.</p>
<p>Publishers soon followed with well-received field guides and encyclopedias detailing observations of what were seen through early microscopes. For example, a Scottish encyclopedia published in 1859, “<a href="https://www.nms.ac.uk/collections-research/our-research/highlights-of-previous-projects/chambers-collection/">Chambers’s Encyclopaedia: A Dictionary of Universal Knowledge for the People</a>,” sought to broadly explain the natural world through woodblock illustrations of mammals, microorganisms, birds and reptiles.</p>
<p>These publications responded to the public’s demand for more news and views of the natural world. People formed amateur naturalist societies, hunted for fossils, and enjoyed trips to local zoos or menageries. By the 19th century, <a href="https://digpodcast.org/2018/04/29/natural-history-museums/">natural history museums</a> were being constructed around the world to share scientific knowledge through illustrations, models and real-life examples. Exhibits ranged from taxidermied animals to human organs preserved in liquid.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Wilhelm Roentgen's X-ray photograph of his wife's hand" src="https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=872&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=872&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=872&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1095&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1095&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1095&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The first X-ray image was the hand of X-ray discoverer Wilhelm Roentgen’s wife.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Wilhelm-Roentgen's-X-ray-photograph-of-his-wife's-hand.png">Wilhelm Conrad Röntgen/Brockhaus Multimedial via Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>What began as hand drawings has morphed over the past 150 years with the help of new technologies. The advent of sophisticated imaging techniques such as <a href="https://www.nde-ed.org/NDETechniques/Radiography/Introduction/history.xhtml">X-rays</a> in 1895, <a href="https://www.thermofisher.com/blog/microscopy/the-history-of-the-electron-microscope/">electron microscopes</a> in 1931, <a href="https://doi.org/10.1016/j.tcb.2011.09.007">3D modeling</a> in the 1960s and <a href="https://pubs.rsna.org/doi/10.1148/radiol.14140706">magnetic resonance imaging, or MRI</a> in 1973 made it easier for scientists to share what they were seeing in the lab. In fact, Wilhelm Roentgen, a physics professor who first discovered the X-ray, made the first human X-ray image with his wife’s hand.</p>
<p>Today, scientific publications including <a href="https://doi.org/10.1038/s41594-021-00587-5">Nature</a> and <a href="https://www.the-scientist.com/profession/bioscience-moves-into-galleries-as-bioart-52533">The Scientist</a> have taken to sharing their favorites with readers. Visualizations, whether through photography or video, are one more method for scientists to document, test and affirm their research.</p>
<h2>Science, art and K-12 education</h2>
<p>These science visualizations have found their way into classrooms, as K-12 schools add scientific photographs and videos to lesson plans. </p>
<p>Art museums, for example, have developed <a href="https://www.getty.edu/education/teachers/classroom_resources/curricula/art_science2/">science curricula based on art</a> to give students a glimpse of what science looks like. This can help promote <a href="https://doi.org/10.1073/pnas.1912436117">scientific literacy</a>, increasing both their understanding of basic scientific principles and their critical thinking skills.</p>
<p>Scientific literacy is especially important now. During a pandemic in which misinformation about COVID-19 and vaccines has been rampant, a better understanding of natural phenomena could help students learn how to make informed decisions about disease risk and transmission. Teaching scientific literacy gives students the skills to <a href="https://techonomy.com/2020/07/science-literacy-and-americas-covid-crisis/">evaluate the claims</a> of both scientists and public figures, whether they’re about COVID-19, the common cold or climate change.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Hindlimbs from chick embryos." src="https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=352&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=352&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=352&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=442&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=442&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=442&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A winner of the 2020 BioArt contest, this image shows hind limbs from chick embryos. The left limb is normal, while the right is a mutant. The yellow staining indicates the presence of a protein that marks progenitors of bone and cartilage development.</span>
<span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2020BioArtWinners/hindlimbs_1.jpg">Christian Bonatto/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>However, science knowledge appears to be stagnating. The <a href="https://www.nationsreportcard.gov/science/?grade=4">2019 National Assessment of Education Progress</a> measures the science knowledge and scientific inquiry capabilities of U.S. public school students in grades 4, 8 and 12 from a scale of zero to 300. Scores stagnated for all grades from 2009 to 2019, hovering between 150 to 154.</p>
<p>[<em>Too busy to read another daily email?</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-toobusy">Get one of The Conversation’s curated weekly newsletters</a>.]</p>
<p>A survey of K-12 teachers shows that 77% of elementary teachers spend <a href="https://www.nationsreportcard.gov/science/student-experiences/?grade=4">under four hours a week on science</a>. And the 2018 National Survey of Science and Mathematics Education found that K-3 students receive an average of only <a href="http://horizon-research.com/NSSME/2018-nssme/research-products/reports/highlights-2018-nssme">18 minutes of science instruction per day</a>, compared to 57 minutes in math.</p>
<p>Making science more visual may make <a href="https://www.firstdiscoverers.co.uk/science-education-early-childhood/">learning science at an early age</a> easier. It could also help students both understand scientific models and develop skills like teamwork and how to communicate complex concepts.</p>
<h2>Deepening scientific knowledge</h2>
<p>The <a href="https://faseb.org/partnerships-and-outreach/bioart">BioArt Scientific Image and Video Competition</a> was established 10 years ago to both give scientists an outlet to share their latest research and allow a wider audience to view bioscience from the researcher’s point of view.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Electron microscope image of HeLa cells infected with Listeria monocytogenes." src="https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=840&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=840&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=840&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1056&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1056&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1056&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A winner of the 2020 BioArt contest, this image shows HeLa cells infected with the common but fatal foodborne pathogen Listeria monocytogenes.</span>
<span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/dhanda.png">Arandeep Dhanda/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>What’s unique about the BioArt competition is the diversity of submissions over the past decade. After all, bioscience encompasses the wide range of disciplines within the life sciences. The 2021 BioArt contest winners range from a <a href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/nacke.png">zebra fish embryo’s developing eye</a> to the shell of a species of <a href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/smith.png">96 million-year-old helochelydrid fossil turtle</a>.</p>
<p>I have served as a judge for the BioArt competition over the past five years. My appreciation for the science behind the images is often exceeded by my enjoyment of their beauty and technical skill. For instance, photography using <a href="https://www.popphoto.com/tips-pro-microscopic-photography/">polarized light</a>, which filters light waves so they oscillate in one direction instead of many directions, allows scientists to reveal what the otherwise hidden insides of samples look like.</p>
<p>Whether today or in the past, science elucidates the foundation of our world, both in miniature and at scale. It’s my hope that visually illuminating scientific processes and concepts can advance scientific literacy and give both students and the general public access to a deeper understanding of the natural world that they need to be informed citizens. That those images and videos are often beautiful is an added benefit.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/1Q9j9QvHO4U?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This video by 2021 BioArt winner Thomas Gebert shows a human intestinal organoid infected with rotavirus.</span></figcaption>
</figure><img src="https://counter.theconversation.com/content/168925/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Curran receives funding from the National Institutes of Health and the National Science Foundation. She is a member of the FASEB Board of Directors. </span></em></p>Scientists have been using art to illuminate and share their research with the public for centuries. And art could be one way to bolster K-12 science education and scientific literacy in the public.Chris Curran, Professor and Director Neuroscience Program, Northern Kentucky UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1706102021-10-27T15:00:50Z2021-10-27T15:00:50ZParasitic wasps turn other insects into ‘zombies,’ saving millions of humans along the way<figure><img src="https://images.theconversation.com/files/428670/original/file-20211027-13-ipypy2.jpg?ixlib=rb-1.1.0&rect=0%2C47%2C10577%2C6982&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The diaphanous wings and striking markings of this parasitic wasp (Arotes decorus) belie its gruesome nature.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Wasps have a <a href="https://askentomologists.com/2015/09/27/please-stop-sharing-the-wasps-are-jerks-memes/">reputation for being jerks</a> because of their perceived aggressiveness and ability to sting repeatedly. They’re often negatively compared with the honey production and agricultural pollination of bees. </p>
<p>If wasps are jerks, however, they are positively saintly compared to their parasitic brethren. </p>
<p>Parasitic wasps sting to inject their eggs into a host, often accompanied by venom and a virus. Their larvae grow and eventually emerge from the unwitting host — usually killing it. Then they becoming adults and fly off to continue the cycle. </p>
<p>Some wasps go further, controlling their host’s behaviour, effectively “zombifying” them to help the larva survive. After studying the behaviour of ichneumon wasps, which lay their eggs in moth larvae, naturalist Charles Darwin wrote that they were so evil that they were proof against the idea that God was directing evolution: </p>
<blockquote>
<p>“<a href="https://www.darwinproject.ac.uk/letter/DCP-LETT-2814.xml">I cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonidæ with the express intention of their feeding within the living bodies of caterpillars</a>.” </p>
</blockquote>
<p>While no wasps are known to lay eggs in humans (although <a href="https://www.cdc.gov/parasites/myiasis/biology.html">some flies do</a>), they have inspired films like the <em>Alien</em> franchise and the recently released monster survival video game <a href="https://thedarkpictures.fandom.com/wiki/Alien_Parasites"><em>House of Ashes</em></a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/jQ5lPt9edzQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Ridley Scott’s 1979 movie ‘Alien’ centred on a parasitic alien species.</span></figcaption>
</figure>
<p>But whether inspiring horror or metaphysical questions, parasitic wasps also save millions of human lives.</p>
<h2>Parasitic wasps to the rescue</h2>
<p>In the 1970s, the cassava mealybug (<em>Phenacoccus manihoti</em>) entered Western and Central Africa as an <a href="https://doi.org/10.1016/0167-8809(90)90122-T">invasive pest species from Brazil</a>. It rapidly spread across cassava fields causing <a href="https://doi.org/10.1146/annurev.en.36.010191.001353">crop losses as high as 80 per cent</a>. The cassava plant is a staple food crop <a href="https://doi.org/10.1016/0167-8809(93)90032-K">because it is drought-resistant</a>. The mealybug invasion threatened the <a href="https://www.fao.org/3/a0154e/a0154e02.htm">food base of 200 million people</a>. </p>
<p>The Swiss entomologist Hans Rudolf Herren, who was conducting research in the area, <a href="https://doi.org/10.1111/j.1570-7458.1986.tb01013.x">found a wasp parasitizing the mealybug</a> (<em>Epidinocarsis lopezi</em>). The parasitic wasp posed <a href="https://doi.org/10.1006/bcon.2001.0937">little risk to sub-Saharan species</a>. </p>
<p>After <a href="https://doi.org/10.1111/j.1570-7458.1985.tb03515.x">rearing the wasps</a> and gathering funding, <a href="https://www.worldfoodprize.org/en/laureates/19871999_laureates/1995_herren/">Herren bought planes</a> and co-ordinated <a href="https://doi.org/10.1146/annurev.en.36.010191.001353">strategic airdrops and ground release of wasp cocoons</a> to areas affected by the mealybug. From those locations, the wasp populations grew and spread on their own, <a href="https://doi.org/10.1006/bcon.2001.0937">reducing the mealybug population to manageable levels for years</a>. </p>
<p>This effort <a href="https://doi.org/10.1111/j.1574-0862.2009.00427.x">saved an estimated 20 million lives</a>, billions in crops and avoided the use of pesticides. Herren received the <a href="https://www.worldfoodprize.org/en/laureates/19871999_laureates/1995_herren/">World Food Prize in 1995 for his efforts</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/3E-r80C_6tE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">David Attenborough describes the habits of parasitic wasps for BBC Earth.</span></figcaption>
</figure>
<h2>Biocontrol heroes</h2>
<p><a href="https://biocontrol.entomology.cornell.edu/what.php">Biocontrol is the use of one organism to combat a pest</a>, and this was far from the only successful case of wasps as biocontrol. Wasps have successfully defended against many crop pests <a href="https://doi.org/10.1016/S2095-3119(18)62078-7">in Chinese agriculture</a>. </p>
<p>The samurai wasp (<em>Trissolcus japonicus</em>) was being studied for potential use against the brown marmorated stinkbug, a threat to many crops across the continental United States. However, the wasp preempted this, <a href="https://www.science.org/content/article/scientists-spent-years-plan-import-wasp-kill-stinkbugs-then-it-showed-its-own">moving into stinkbug territories on its own</a>. </p>
<p>Wasps are even being deployed to prevent moths from <a href="https://www.bbc.com/news/uk-england-norfolk-56086274">damaging historical sites and their artifacts</a>. Here in Canada, at least four wasp species have been <a href="https://www.cbc.ca/news/canada/ottawa/emerald-ash-borer-wasps-fight-1.4303129">released to control the emerald ash borer</a>, a cause of deforestation across Canada.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-invasive-emerald-ash-borer-has-destroyed-millions-of-trees-scientists-aim-to-control-it-with-tiny-parasitic-wasps-158403">The invasive emerald ash borer has destroyed millions of trees – scientists aim to control it with tiny parasitic wasps</a>
</strong>
</em>
</p>
<hr>
<h2>Pros and cons</h2>
<p>Biocontrol has several advantages over pesticides. Populations can grow and spread on their own, as demonstrated by the samurai wasps, whereas pesticides typically need humans to spread them. Organisms can <a href="https://doi.org/10.1006/bcon.1994.1032">maintain their presence over the long-term without human intervention</a>, while pesticides often require repeat applications. Pests can also evolve to resist pesticides in <a href="https://doi.org/10.1002/ps.4899">as few as 20 generations</a>. And as biocontrol uses another organism, they can evolve in response the pest’s defences.</p>
<p>Biocontrol is not free from issues. It often introduces a new invasive species to deal with an existing one. It can be difficult to <a href="https://doi.org/10.1006/bcon.2001.0937">predict the effects of a new species on an unprepared ecosystem</a>. </p>
<p>For example, the cane toad was introduced in Australia to eat several insect pests there. Instead, the poisonous toad <a href="https://www.awe.gov.au/environment/biodiversity/threatened/key-threatening-processes/biological-effects-cane-toads">became a lethal meal for several native species</a>, disrupting many other parts of the ecosystems there. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a kookaburra eating a cane toad" src="https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=489&fit=crop&dpr=1 754w, https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=489&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/428680/original/file-20211027-15-1y65pcf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=489&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A laughing kookaburra eats a cane toad. Some kookaburras die from ingesting the poisonous toads.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Parasites may avoid some of these issues as, unlike predators, <a href="https://doi.org/10.1146/annurev.en.36.010191.002413">they are often limited to a single or very few host species</a>, making them less likely to go off-target and affect species other than the intended one. </p>
<p>Given that <a href="https://doi.org/10.1016/B978-0-12-800876-8.00006-0">most agricultural pests are insects</a> and <a href="https://doi.org/10.1038/326788a0">most pest insects are targeted by at least one parasitic wasp</a> (<a href="https://doi.org/10.1186/s12898-018-0176-x">there are an estimated 750,000 parasitic wasp species</a>), this gives a legion of options to study for safe and effective pest management.</p>
<p>So next time you’re online and see wasps being unfairly maligned, consider the millions of humans across the world who are alive and able to feed themselves because of them. And maybe this upcoming Halloween, should you encounter the spirit of a certain 1800s English naturalist going on about the theological implications of parasitic wasps’ evil, tell him of the good they can do.</p><img src="https://counter.theconversation.com/content/170610/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dylan Miller receives funding from NSERC (Natural Science and Engineering Council of Canada)</span></em></p><p class="fine-print"><em><span>Shelley Adamo receives funding from NSERC (Natural Science and Engineering Council of Canada) </span></em></p>Parasitic wasps are body-snatchers — if you’re an insect. But these much-maligned creatures have saved millions of human lives by controlling the spread of the cassava mealybug.Dylan Miller, PhD student, Neuroscience, Dalhousie UniversityShelley Adamo, Professor, Psychology and Neuroscience, Dalhousie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1656632021-08-15T19:51:24Z2021-08-15T19:51:24ZIf I could go anywhere: a world through the eyes of botanical artist Marianne North at Kew Gardens<figure><img src="https://images.theconversation.com/files/415796/original/file-20210812-17-1uhi1tt.jpg?ixlib=rb-1.1.0&rect=12%2C15%2C2023%2C1278&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Marianne North Gallery at Kew Gardens.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/helen61/4911340028/in/photolist-8tZUhm-azTJF8-eiSJi9-77XpwL-kB9aR-hpeBaw-S6ABkG-7sqAP4-9L63Wt-p4z8Zx-p6RV8K-867FLL-qaHJhg-qEae3z-dy8ZJm-dy8ZGs-hEWV5X-sWerkq-9RVnez-bjwVWA-dVBbrQ-xkxTsU-Q6XuTq-2j7vrRv-dy8ZEh-Curwec-U6hknT-S8euYU-W4iPqw-o86GTS-9vz7iw-9vw5TP-4reKxi-eWa3Er-V8djdL-Q6Xuzu-9vw6hT-U4vFy1-2j6dEtu-eWa2qV-4riRc1-4riRj3-2j6f2nK-2gxuvpC-JU18x-XVVBnp-4zVfAS-2gxuwdS-4riR8f-Fb3bBZ/">Flickr/Helen.2006</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p><em>In <a href="https://theconversation.com/au/topics/if-i-could-go-anywhere-102157">this series</a> we pay tribute to the art we wish could visit — and hope to see once travel restrictions are lifted.</em></p>
<p>Have you ever entered a gallery, cathedral or grand old ballroom and drawn breath with surprise? Usually, it is opulence, vastness or one stunning painting or sculpture that evokes this response — think Michelangelo’s David, or Chartres Cathedral or the hall of mirrors at Versailles.</p>
<p>In London, an extraordinary gallery draws gasps because there is none like it anywhere else. It is like entering a giant “globe” covered in paintings of faraway places and plants. You can walk from South America to North America to Asia in a few paces. </p>
<p>All the paintings are by the Victorian-era female botanical artist and explorer <a href="https://www.kew.org/read-and-watch/marianne-north-botanical-artist">Marianne North</a>. The small gallery nestles in a stunning natural setting — Kew Gardens beside the Thames River.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/if-i-could-go-anywhere-marie-antoinettes-private-boudoir-and-mechanical-mirror-room-at-versailles-160599">If I could go anywhere: Marie Antoinette's private boudoir and mechanical mirror room at Versailles</a>
</strong>
</em>
</p>
<hr>
<h2>A very intrepid painter</h2>
<p>The design of the gallery and the layout of the 800-plus paintings were largely North’s idea, assisted by Kew Gardens staff. Though she was a largely self-taught botanical illustrator, she also discovered four specimens that were named in her honour.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman with palm trees" src="https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=893&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=893&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=893&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1122&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1122&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415791/original/file-20210812-20-1gzn2je.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1122&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Victorian-era adventurer and artist Marianne North, photographed at her home in Ceylon by Julia Margaret Cameron around the 1870s.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Marianne_North01.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>I remember my first impression of the peacefulness and softness on entering the gallery, elicited by a timber-panelled gallery covered top-to-bottom with paintings. It is a tightly packed mosaic of artworks.</p>
<p>Then I notice the gold lettering of countries and continents above the panels —America, Australia, Japan, Jamaica — and begin to explore the natural world as it was in Victorian times.</p>
<p>The vibrancy, colour and beauty in each individual painting emerges on closer viewing.</p>
<p>I walk from one continent to another noticing the unique vegetation of each, but also the similarity and diversity of natural forms — when these paintings were being created and collated, Charles Darwin had already written:</p>
<blockquote>
<p>[…] endless forms most beautiful and most wonderful have been, and are being, evolved.</p>
</blockquote>
<p>The gallery displays this exquisitely, from a grand avenue of Indian rubber trees in Ceylon (Sri Lanka), medicinal plants from the tropics, vivid tangerine flowers on coral trees in Brazil, early coffee plantations in Jamaica, to a tall and majestic monkey puzzle tree in Chile. Australian banksia, bottle tree and bottle-brush are accurately and beautifully depicted. </p>
<p>Within the walls of the gallery, I can even travel back in time to see what <a href="https://www.jstor.org/stable/26780344">Mudgee in NSW looked like</a> in the late 1800s.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/YmF_6KAkvck?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Over 14 years, Marianne North visited 15 countries and created more than 800 detailed paintings.</span></figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/friday-essay-the-forgotten-german-botanist-who-took-200-000-australian-plants-to-europe-143099">Friday essay: the forgotten German botanist who took 200,000 Australian plants to Europe</a>
</strong>
</em>
</p>
<hr>
<p>Then there are the four specimens <a href="https://www.goodreads.com/book/show/12395284-marianne-north?from_search=true&from_srp=true&qid=B3GmE47b2w&rank=5">named in North’s honour</a>. <em>Kniphofia northiae</em>, discovered in South Africa, now grows in many gardens with the common name red hot poker (<a href="https://images.kew.org/botanical-art/marianne-north/367-a-giant-kniphofia-near-grahamstown-4991693.html">Painting no. 367</a>). <em>Northia seychellana</em> is also called the capucin tree <a href="http://plantillustrations.org/illustration.php?id_illustration=329734&id_taxon=8027&mobile=0&SID=c8vg74l4peg5bljdcr7m1kccvf&language=English&thumbnails_selectable=0&selected_thumbnail=0&query_type=species&query_broad_or_restricted=broad&group=0&lay_out=0&uhd=0">Painting no. 501</a>). <em>Nepenthes northiana</em>, a large and unusual pitcher plant, was discovered by Marianne in Borneo (<a href="http://www.kew.org/mng/gallery/561.html">Painting no. 561</a>). And <em>crinum northianum</em> , in the lily family (<a href="https://images.kew.org/botanical-art/marianne-north/602-bornean-crinum-5122279.html">Painting no. 602</a>), comes from Sarawak, Borneo.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="pitcher plant drawing" src="https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=846&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=846&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=846&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1063&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1063&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415794/original/file-20210812-14-18qzmef.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1063&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A New Pitcher Plant from the Limestone Mountains of Sarawak Borneo, painted by Marianne North, circa 1876.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:MN561_A_New_Pitcher_Plant_from_the_Limestone_Mountains_of_Sarawak,_Borneo.jpg">Wikimedia Commons/Royal Botanic Gardens Kew</a></span>
</figcaption>
</figure>
<h2>When Charles met Marianne</h2>
<p>North was one of several Victorian-era British female explorers. She was born (1830) into a wealthy family and had early connections to Kew gardens since her father knew its first director, <a href="https://www.kew.org/read-and-watch/william-hooker-and-a-case-of-mistaken-identity">Sir William Hooker</a>. </p>
<p>Her interest in botanical art grew as an educational activity and as a means of passing on knowledge in pre-photography times. She made nearly 900 works from across the continents and larger islands.</p>
<p>North set out on her first main botanical tours in the 1870s, 40 years after Darwin sailed on HMS Beagle, determined to “paint from nature”. Her paintings of vegetation, birds, mammals and terrain, depicted with close accuracy, helped to foster awareness of the evolutionary connections between plants, animals and environment. </p>
<p>North and Darwin were in fact <a href="https://www.darwinproject.ac.uk/marianne-north">acquainted</a>. In 1880 they met and discussed her paintings and he advised her to see and paint the <a href="https://www.plantexplorers.com/explorers/botanical-artists/marianne-north.htm">Australian vegetation</a> “which was unlike that of any other country”. North took Darwin’s advice, and returned to Down house in 1881 with a new collection spanning Townsville to Perth.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="painting of flowers and landscape" src="https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=435&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=435&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=435&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=547&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=547&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415797/original/file-20210812-26-1tl43cs.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=547&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">View near Brighton, Victoria by Marianne North, circa 1879.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Marianne_North_(1830-1890)_-_View_near_Brighton,_Victoria_-_MN752_-_Marianne_North_Gallery,_Royal_Botanic_Gardens,_Kew.jpg">Wikimedia Commons/Royal Botanic Gardens Kew</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/guide-to-the-classics-darwins-the-descent-of-man-150-years-on-sex-race-and-our-lowly-ape-ancestry-155305">Guide to the classics: Darwin's The Descent of Man 150 years on — sex, race and our 'lowly' ape ancestry</a>
</strong>
</em>
</p>
<hr>
<h2>The world through her eyes</h2>
<p>North gifted her botanical collection to Kew Gardens along with a gallery to house it. She arranged the paintings and also the decorations surrounding the doors to the gallery. Hence the unique design and global feel of the <a href="https://www.kew.org/kew-gardens/whats-in-the-gardens/marianne-north-gallery">gallery interior</a>. It opened in 1882.</p>
<p>Some 140 years later, we can explore her adventurous life and travels and view a global nature study in one gallery. With today’s technology we can see much of it <a href="https://www.kew.org/search?textsearch=marianne+north">online</a>, which is handy during lockdown. I wonder what human expansion and global warming have done to those special places? If I could retrace North’s steps, what would I see?</p>
<p>After “browsing the continents”, you can exit the gallery into <a href="https://www.kew.org/kew-gardens">Kew Gardens</a>. Among the 50,000 plants at the World Heritage site, you can search for the rare Australian Wollemi Pine, growing quite vigorously in the grounds.</p>
<p>The <a href="https://www.goodreads.com/quotes/1316181-there-is-grandeur-in-this-view-of-life-with-its">words</a> of Darwin in 1859’s Origin of Species come to mind: “There is grandeur in this view of life”.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="tree painting" src="https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415799/original/file-20210812-15-s32y6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">African Baobab Tree in the Princess’s Garden at Tanjore, India. Painted by Marianne North, circa 1878.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Marianne_North_(1830-1890)_-_African_Baobab_Tree_in_the_Princess%27s_Garden_at_Tanjore,_India_-_MN262_-_Marianne_North_Gallery,_Royal_Botanic_Gardens,_Kew.jpg">Wikimedia Commons/Royal Botanic Gardens Kew</a></span>
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Read more:
<a href="https://theconversation.com/janet-laurence-after-nature-sounds-an-exquisite-warning-bell-for-extinction-112942">Janet Laurence: After Nature sounds an exquisite warning bell for extinction</a>
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<img src="https://counter.theconversation.com/content/165663/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mary Voice does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A special gallery in London’s Kew Gardens allows the visitor to travel the world via the 800-plus detailed paintings of Marianne North, Victorian-era adventurer and botanical artist.Mary Voice, Lecturer - Climate (Honorary), The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1627112021-06-17T15:37:28Z2021-06-17T15:37:28ZDarwin got sexual selection backwards, research suggests<figure><img src="https://images.theconversation.com/files/406739/original/file-20210616-13-330jub.jpeg?ixlib=rb-1.1.0&rect=46%2C7%2C5184%2C3391&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Males elephant seals dwarf their female counterparts. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/northern-elephant-seal-mirounga-angustirostris-male-440246053">Sean Lema/Shutterstock</a></span></figcaption></figure><p>Charles Darwin was a careful scientist. In the middle of the 19th century, while he was collecting evidence for his theory that species evolve by <a href="https://www.nationalgeographic.org/encyclopedia/natural-selection/">natural selection</a>, he noticed it didn’t explain the fancy tails of male peacocks, the antlers paraded by male deer, or why some the males of some species are far larger then their female counterparts.</p>
<hr>
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<p>For these <a href="https://theconversation.com/these-useless-quirks-of-evolution-are-actually-evidence-for-the-theory-107395">quirks</a>, Darwin proposed a secondary theory: the <a href="http://darwin-online.org.uk/content/frameset?pageseq=1&itemID=F937.1&viewtype=text">sexual selection</a> of traits that increase an animal’s chance of securing a mate and reproducing. He carefully distinguished between weapons such as horns, spurs, fangs and sheer size that are used to subdue competing rivals, and ornaments that are aimed at charming the opposite sex.</p>
<p>Darwin thought that sexually selected traits could be explained by uneven sex ratios – when there are more males than females in a population, or vice versa. <a href="http://darwin-online.org.uk/content/frameset?pageseq=1&itemID=F937.1&viewtype=text">He reasoned</a> that a male with fewer available females would have to work harder to secure one of them as a mate, and that this competition would drive sexual selection. </p>
<p>In a <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/evo.14273">new study</a>, my colleagues and I have confirmed a link between sexual selection and sex ratios, as Darwin suspected. But surprisingly, our findings suggest Darwin got things the wrong way round. We found that sexual selection is most pronounced not when potential mates are scarce, but when they’re abundant – and this means looking again at the selection pressures at play in animal populations that feature uneven sex ratios. </p>
<p>Since Darwin’s time, we’ve learned a lot about uneven sex ratios, which are common in wild animal populations. For instance, in many <a href="https://www.nature.com/articles/6883570/">butterflies</a> and <a href="https://www.journals.uchicago.edu/doi/abs/10.1086/415033">mammals</a>, including humans, the number of adult females exceeds the number of adult males.</p>
<p>This skew is most extreme <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jeb.12415">among marsupials</a>. In Australian antechinus, for instance, all males <a href="https://www.livescience.com/40229-marsupials-mate-to-death.html">abruptly die</a> after the mating season, so there are times when no adult males are alive and the entire adult population is made up of pregnant females. </p>
<p>In contrast, many birds parade more males than females in their populations. In some plovers, for example, the males <a href="https://www.onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2011.02305.x">outnumber females</a> by six to one.</p>
<p>So why do many birds species have more males, while mammals often have more females? The short answer is that we don’t know. But there are smoking guns. </p>
<h2>Explaining uneven sex ratios</h2>
<p>Some uneven sex ratios can be partially explained by <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2019.0867">lifespan differences</a>. <a href="https://pubmed.ncbi.nlm.nih.gov/32205429/">Female mammals</a>, including humans, usually outlive their male counterparts by a wide margin. In humans, females live on average about <a href="https://www.bbc.com/future/article/20151001-why-women-live-longer-than-men">5% longer</a> than males. In <a href="https://press.uchicago.edu/ucp/books/book/chicago/R/bo3620491.html">African lions</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/24317695/">killer whales</a>, the female lifespan is longer by up to 50%.</p>
<p>Predator preferences could also play a part. African lions kill approximately <a href="https://oxford.universitypressscholarship.com/view/10.1093/acprof:oso/9780199208784.001.0001/acprof-9780199208784">seven times more</a> male than female buffalo, because male buffalo tend to roam alone, whereas females are protected within herds. In contrast, cheetahs kill <a href="https://academic.oup.com/jmammal/article/80/4/1084/851830">many more female</a> Thompson’s gazelles than males, presumably because they can outrun female gazelles easier – especially the pregnant ones.</p>
<figure class="align-center ">
<img alt="A lion in front of a herd of buffalo" src="https://images.theconversation.com/files/406743/original/file-20210616-3862-g8e4ss.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406743/original/file-20210616-3862-g8e4ss.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=323&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406743/original/file-20210616-3862-g8e4ss.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=323&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406743/original/file-20210616-3862-g8e4ss.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=323&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406743/original/file-20210616-3862-g8e4ss.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=405&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406743/original/file-20210616-3862-g8e4ss.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=405&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406743/original/file-20210616-3862-g8e4ss.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=405&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Lions don’t appear to fancy their chances against a herd of female buffalo.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/african-buffalo-747035347">Seyms Brugger/Shutterstock</a></span>
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<p>Finally, males and females often <a href="https://pubmed.ncbi.nlm.nih.gov/8982783/">suffer differently</a> from parasites and diseases. The COVID-19 pandemic is a striking example of this: the number of infected men and women is similar in most countries, but male patients have <a href="https://theconversation.com/coronavirus-the-puzzle-of-why-the-risk-of-death-is-greater-for-men-and-for-the-elderly-135176">higher odds of death</a> compared to female ones.</p>
<h2>Sex ratios and sexual selection</h2>
<p>Despite our growing knowledge of uneven sex ratios, Darwin’s insight linking sex ratios with sexual selection has received little attention from scientists. Our study sought to address this, pulling together these two strands of evolutionary theory in order to revisit Darwin’s argument.</p>
<p>We looked in particular at the evolution of <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/evo.14273">large males</a> in different species, which are often several times larger than their female counterparts. We see this in <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.10011">male baboons</a>, <a href="https://link.springer.com/article/10.1007%2Fs00265-002-0507-x">elephant seals</a> and <a href="https://academic.oup.com/beheco/article/15/4/592/205890">migratory birds</a>, for example. </p>
<p>Sometimes, females are larger than males – as with some species of <a href="https://oxford.universitypressscholarship.com/view/10.1093/acprof:oso/9780199208784.001.0001/acprof-9780199208784-chapter-4">bird</a>, such as the African jacana. The scientific term for when one sex in a species is larger than the other is “<a href="https://www.oxfordbibliographies.com/view/document/obo-9780199941728/obo-9780199941728-0110.xml">sexual size dimorphism</a>”. </p>
<figure class="align-center ">
<img alt="A larger female African janaca and a smaller male" src="https://images.theconversation.com/files/406957/original/file-20210617-15-18mi7gu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406957/original/file-20210617-15-18mi7gu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406957/original/file-20210617-15-18mi7gu.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406957/original/file-20210617-15-18mi7gu.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406957/original/file-20210617-15-18mi7gu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406957/original/file-20210617-15-18mi7gu.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406957/original/file-20210617-15-18mi7gu.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The female African jacana, on the left, is larger than the male.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/berniedup/6001942849/">Bernard DUPONT/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>It’s clear how <a href="https://academic.oup.com/condor/article/112/1/183/5152556">sexual selection</a> can sometimes create size dimorphism. Knocking out an enemy requires muscular power, while fight endurance requires stamina. So being bigger often means dominating rivals, thereby winning the evolutionary lottery of reproduction.</p>
<p>Analysing 462 different species of reptiles, mammals and birds, our study found a tight association between sexual size dimorphism and sex ratios, vindicating Darwin’s conjectures. </p>
<p>But the trend was the opposite to the one Darwin predicted with his limited evidence. It turns out the most intense sexual selection – indicated by larger males relative to females – occurred in species where there were plenty of females for males to choose from, rather than a scarcity of females as Darwin suggested.</p>
<h2>Implications for sexual selection</h2>
<p>This in no way invalidates Darwin’s theories of natural selection and sexual selection. Our finding simply shows that a different mechanism to the one Darwin proposed is driving mating competition for animals living in sex-skewed populations.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-slam-dunk-creationists-when-it-comes-to-the-theory-of-evolution-81581">How to slam dunk creationists when it comes to the theory of evolution</a>
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<p>Darwin’s assumption was based on the idea that the most intense competition for mates should occur when there’s a shortage of mating partners. But <a href="https://www.pnas.org/content/106/Supplement_1/10001">more recent theories</a> suggest this logic may not be correct, and that sexual selection is actually a system in which the winner takes all. </p>
<p>That means that when there are many potential partners in the population, a top male – in our study, the largest and heaviest – enjoys a disproportionately high payout, fertilising a large number of females at the expense of smaller males, who may not reproduce at all.</p>
<p>We need further studies to help us understand how males and females seek out new partners in male-skewed and female-skewed populations, and in what circumstances ornaments, armaments and sheer size are particularly useful. Such studies could provide us with unprecedented new insights into how nature works, building on Darwin’s original theory of sexual selection.</p><img src="https://counter.theconversation.com/content/162711/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tamas Szekely receives funding from The Royal Society and theELVONAL programme of Hungarian Research Foundation (NKFIH).</span></em></p>The sexual selection of larger males may be driven by an abundance – not a scarcity – of females.Tamas Szekely, Professor of Biodiversity at The Milner Centre for Evolution, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1553052021-02-24T19:06:02Z2021-02-24T19:06:02ZGuide to the classics: Darwin’s The Descent of Man 150 years on — sex, race and our ‘lowly’ ape ancestry<figure><img src="https://images.theconversation.com/files/385987/original/file-20210223-20-1arcghr.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6709%2C4476&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Jared Rice/Unsplash</span></span></figcaption></figure><p>When Charles Darwin’s theory of evolution was first published in <a href="http://darwin-online.org.uk/EditorialIntroductions/Freeman_OntheOriginofSpecies.html">On the Origin of Species</a> in 1859, the book was conspicuously silent about how his theory applied to humans. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=919&fit=crop&dpr=1 600w, https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=919&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=919&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1155&fit=crop&dpr=1 754w, https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1155&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/386025/original/file-20210224-21-6xn2rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1155&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<p>Darwin believed the subject of human evolution was so “<a href="https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-2192.xml;query=surrounded%20with%20prejudices;brand=default">surrounded with prejudices</a>” he was determined to avoid it entirely. </p>
<p>It was only when he became frustrated by the way others conceived of human evolution that he took up the subject himself. His two-volume <a href="http://darwin-online.org.uk/EditorialIntroductions/Freeman_TheDescentofMan.html">The Descent of Man, and Selection in Relation to Sex</a> was published on 24 February 1871.</p>
<p>Revisiting this work 150 years on, it is striking how some of Darwin’s most radical claims — such as humanity’s ape-like ancestry — are now taken for granted while some of his other views were clearly embedded in Victorian racial and gender stereotypes.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/guide-to-the-classics-darwins-on-the-origin-of-species-96533">Guide to the classics: Darwin's On the Origin of Species</a>
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<h2>Sexual selection</h2>
<p>Darwin’s objective in Descent was threefold: to consider whether humans were descended from a pre-existing form; to consider the nature of human development; and to consider the differences between the “human races”. </p>
<p>In coming to terms with these issues, Darwin focused on the theory of sexual selection.</p>
<p>Darwin’s earlier theory of natural selection explained how the struggle for limited resources led to adaptations that were beneficial to certain individuals of the same species at the expense of others. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Black and white illustration" src="https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=520&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=520&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=520&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=654&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=654&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385736/original/file-20210223-17-ymykv1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=654&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">An illustration of a peacock feather as published in The Descent of Man.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>Sexual selection, in contrast, explained how the struggle for mates led to adaptations with no survival benefit. The bright plumages of male birds of paradise and the spectacular tail of the peacock were a product of mate choice by female birds, he wrote.</p>
<p>A similar process, he theorised, explained the development of specialised weapons for battle, such as the large horns of beetles: a result of males struggling against one another to secure mates.</p>
<p>Applying this principle to humans, Darwin argued that in the early stages of humanity’s development, men took the power of selection away from women. Men struggled against other men to select their mates, he wrote, and so became stronger and more intelligent over time, while women became more nurturing in their pursuit to attract mates through the cultivation of fashion. </p>
<p>It is not difficult to see how this theory of sexual selection naturalised Victorian gender relations.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-darwins-sexual-selection-theory-co-stars-in-the-handmaids-tale-127664">How Darwin's sexual selection theory co-stars in 'The Handmaid's Tale'</a>
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<h2>The development of the races</h2>
<p>For Darwin, sexual selection also explained how different human races had developed. </p>
<p>While he was committed to the theory of <a href="https://en.wikipedia.org/wiki/Monogenism">monogenism</a>, believing humans were a single species, he also adhered to a racial hierarchy. As historian of science Evelleen Richards shows in her <a href="https://press.uchicago.edu/ucp/books/book/chicago/D/bo25338514.html">recent book</a>, Darwin’s encounters with Indigenous peoples during his <a href="https://www.darwinproject.ac.uk/commentary/voyage-hms-beagle">Beagle voyage</a>, circumnavigating the globe between 1831 and 1836, led him to perceive vast physical and intellectual differences between the human races. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Black and white illustration" src="https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/386027/original/file-20210224-19-11kp300.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">RT Pritchett’s drawing of a catamaran off the Brazilian state of Bahia, as seen on the Beagle Voyage.</span>
<span class="attribution"><span class="source">Freshwater and Marine Image Bank at the University of Washington</span></span>
</figcaption>
</figure>
<p>He came to believe many of those differences could be explained by the processes of sexual selection. Differences in skin colour were, for Darwin, the result of diverse aesthetic preferences, which subsequently led to the development of distinct races. And as the races diverged, they were further shaped by inherited customs and social practices. </p>
<p>By accepting a racial hierarchy in this scheme, Darwin believed Indigenous peoples, or “savages” as he called them, represented “early stages” in human development. </p>
<p>In the final observation of the book, Darwin confessed he would rather be related to a “heroic little monkey” than to a “savage who delights to torture his enemies”.</p>
<p>His deeper message, however, was that readers should be consoled by the fact some of the nobler qualities of humans were shared by many of the great apes — even if they seemed to be absent from humanity’s “early stages”.</p>
<h2>What makes humans moral?</h2>
<p>The Descent of Man included three chapters dedicated to the subject of mind and morals. Darwin aimed to show there was “no fundamental difference between man and higher mammals” in their moral and mental faculties. </p>
<p>His moral theory relied heavily on animal observations, including those of dogs, apes, and even bees. He insisted humans shared the capacity to feel guilt, shame, and compassion with other social animals — therefore moral conscience was not unique to humans. </p>
<p>Darwin’s theory rejected essentialist and religious categories of “right” and “wrong”. He postulated different animals developed different moral systems depending on their environment and social structures, famously using bees as an example.</p>
<blockquote>
<p>If, for instance, to take an extreme case, men were reared under precisely the same conditions as hive-bees […] our unmarried females would, like the workerbees, think it a sacred duty to kill their brothers, and mothers would strive to kill their fertile daughters; and no one would think of interfering.</p>
</blockquote>
<p>Morality was the product of factors related to the struggle for survival and reproduction, and not divinely ordained.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Bees!" src="https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/386020/original/file-20210224-23-1c8k2n9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Morality, wrote Darwin, was not absolute: if humans evolved like bees, our understanding of right and wrong would be very different.</span>
<span class="attribution"><span class="source">Eric Ward/Unsplash</span></span>
</figcaption>
</figure>
<h2>Reception</h2>
<p>Even though plant and animal evolution was largely accepted by the scientific community at the time, the subject of human evolution was still highly contentious. Darwin’s views were heatedly debated in the press and in public. </p>
<p>A reviewer for the <a href="https://babel.hathitrust.org/cgi/pt?id=uc1.aa0000296905&view=1up&seq=9">Edinburgh Review</a> observed:</p>
<blockquote>
<p>no book of science has excited a keener interest than Mr. Darwin’s new work on the ‘Descent of Man.’ In the drawingroom it is competing with the last new novel, and in the study it is troubling alike the man of science, the moralist, and the theologian. On every side it is raising a storm of mingled wrath, wonder, and admiration.</p>
</blockquote>
<p>By the end of 1871, the work was translated into Dutch, German, Italian and Russian.</p>
<p>Despite its commercial success, The Descent of Man was heavily criticised. At the beginning of 1872, Darwin lamented “<a href="https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-8199.xml;query=hardly%20any;brand=default">hardly any naturalists</a>” agreed with him on sexual selection. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Charles Darwin, as an ape, holds a mirror up to another ape." src="https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1003&fit=crop&dpr=1 600w, https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1003&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1003&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1260&fit=crop&dpr=1 754w, https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1260&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/386001/original/file-20210223-23-dxudff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1260&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Darwin was frequently caricatured in the press as an ape, as here in a colour lithograph by F. Betbeder.</span>
<span class="attribution"><span class="source">Wellcome Collection</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Most naturalists felt Darwin attributed too much power to female choice, and they rejected the idea other animals could possess an <a href="http://darwin-online.org.uk/content/frameset?itemID=A69&viewtype=text&pageseq=1">aesthetic sensibility</a>.</p>
<p>It was Darwin’s analysis of morality, however, that caused the greatest outrage. He stood accused of undermining the foundation of Christian society by advocating moral relativism.</p>
<p>Leading feminist Frances Power Cobbe rejected Darwin’s theory of morality as “<a href="http://darwin-online.org.uk/converted/pdf/1871_Cobbe_A1034.pdf">simious</a>”, while The Times <a href="https://trove.nla.gov.au/newspaper/article/13241212">thundered</a> Darwin’s ideas could encourage “the most murderous revolutions”.</p>
<p>Darwin received hate mail from offended readers like Mr. D. Thomas, who referred to him as a “<a href="https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-13849.xml;query=old%20Ape;brand=default">venerable old Ape</a>”. Darwin began to be regularly caricatured as an ape in the press.</p>
<h2>Descent today</h2>
<p>Certain aspects of Descent hold up well, such as Darwin’s speculation humans originated from Africa, as evidenced by multiple fossil <a href="https://www.simonandschuster.com/books/Ancestral-Passions/Virginia-Morell/9780684824703">discoveries</a> in the mid-20th century, notably by Mary and Louis Leakey.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=765&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=765&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=765&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=961&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=961&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385740/original/file-20210223-20-1cbk5jr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=961&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Charles Darwin.</span>
<span class="attribution"><span class="source">Wellcome Collection</span></span>
</figcaption>
</figure>
<p>Many of his controversial insights in relation to morality have been central to <a href="https://www.cambridge.org/core/books/cambridge-handbook-of-evolutionary-ethics/F61CC795F8DC662B0177EA90EA7EBE46#fndtn-information">recent debates</a> about “evolutionary ethics” among moral philosophers considering the relationship between our understanding of morality and evolution.</p>
<p>And his theory of mind and morals informed the development of multiple scientific disciplines in the 20th century, including evolutionary psychology, <a href="https://press.princeton.edu/books/hardcover/9780691191140/a-most-interesting-problem">neuroscience</a>, and <a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674323353">psychoanalysis</a>.</p>
<p>The same cannot be said about Darwin’s theory of sexual selection. While the idea of “female choice” has been <a href="https://jhupbooks.press.jhu.edu/title/looking-few-good-males">revived several times</a>, such as in Robert Trivers’s <a href="https://en.wikipedia.org/wiki/Parental_investment">parental investment theory</a> which argues the sex that takes on the primary caring role has the greatest choice in a mate, there is very little consensus on the relationship between <a href="https://www.springer.com/gp/book/9789401795845">mate choice and beauty</a>. </p>
<p>Moreover, <a href="https://press.uchicago.edu/ucp/books/book/chicago/D/bo25338514.html">most evolutionists</a> consider male combat — as Darwin wrote about in horned beetles — a form of natural selection, rather than sexual selection. </p>
<p>And when it comes to Darwin’s general views of race and gender, he very much appears a man of his time and social background.</p>
<p>Today, what is most compelling about The Descent of Man is how Darwin’s portrayal of humans was made within the context of a system of evolution that applied equally to all of nature. At a time when other evolutionists stressed humanity’s uniqueness, Darwin instead sought to uncover man’s “lowly nature”.</p><img src="https://counter.theconversation.com/content/155305/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Hesketh receives funding from the Australian Research Council (grant number FT170100194). </span></em></p><p class="fine-print"><em><span>Henry-James Meiring does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>First published 150 years ago, this work is shaped by Victorian-era sexual and racial stereotypes. But at a time when other evolutionists stressed humanity’s uniqueness, Darwin emphasised our ‘lowly nature’.Ian Hesketh, ARC Future Fellow and Association Professor, The University of QueenslandHenry-James Meiring, PhD Candidate, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1444652021-01-15T13:16:30Z2021-01-15T13:16:30ZFrancis Galton pioneered scientific advances in many fields – but also founded the racist pseudoscience of eugenics<figure><img src="https://images.theconversation.com/files/377066/original/file-20210104-17-54ld8q.jpg?ixlib=rb-1.1.0&rect=5%2C263%2C3449%2C2891&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A man of genius – but his ideas were not to the benefit of all humankind.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/united-kingdom-london-national-portrait-gallery-whole-news-photo/843192936">Mondadori Portfolio/Hulton Fine Art Collection via Getty Images</a></span></figcaption></figure><p>A popular pseudoscience was leaving its mark on American culture a century ago in everything from <a href="http://www.eugenicsarchive.org/html/eugenics/essay9text.html">massive reductions</a> in quotas for immigration to the U.S., to thousands of “<a href="http://www.eugenicsarchive.org/eugenics/topics_fs.pl?theme=8">fitter family” contests</a> at county fairs, to a growing acceptance of <a href="https://www.pbs.org/wgbh/americanexperience/features/pill-eugenics-and-birth-control/">birth control</a> by those who thought it could curtail the fertility of “undesirables.”</p>
<p>These are just a few examples of the influence of eugenics in the early 20th century. The idea of scientist Francis Galton, eugenics suggested that negative traits could be bred out of the human species by discouraging reproduction by those considered inferior. It laid the groundwork for <a href="https://www.npr.org/sections/health-shots/2016/03/07/469478098/the-supreme-court-ruling-that-led-to-70-000-forced-sterilizations">forced sterilization laws</a> in the U.S. and <a href="https://encyclopedia.ushmm.org/content/en/article/the-biological-state-nazi-racial-hygiene-1933-1939">Nazi “racial hygiene”</a> programs and the Holocaust. </p>
<p>While Galton is primarily remembered today, 110 years after his death, as the father of the shameful pseudoscience of eugenics, during his life he was considered one of the most influential thinkers of his day. He made seminal contributions in fields as diverse as statistics, geology, meteorology, anthropology, psychology, biology and psychometrics. My interest in Galton was renewed through my university’s decision to remove from buildings the name of one of its past presidents – <a href="https://www.insidehighered.com/news/2020/09/28/indiana-u-rename-landmarks-named-david-starr-jordan">David Starr Jordan</a> – who also happened to be a eugenicist.</p>
<h2>Scientific contributions</h2>
<p>Galton was a pioneer in meteorology, the study of weather. His 1863 book “<a href="http://galton.org/books/meteorographica/galton-1863-meteorographica-color-alt.pdf">Meteorographica</a>” was the first to describe weather on a continental scale. He developed instruments for measuring different weather parameters, described the use of barometric pressure in weather prediction, and devised systems for recording weather information. He <a href="http://galton.org/meteorologist.html">published the world’s first weather map</a> in a newspaper, showing the reported weather in England on March 31, 1875.</p>
<p>Galton was an innovator in the field of statistics, the first to recognize the “wisdom of the crowd.” He once attended a livestock fair where villagers were asked to guess the weight of an ox. Nearly 800 people participated. When Galton looked at their estimates, he found that while almost all the guesses were wrong, both the middle guess and the average of the guesses were almost exactly correct. From such observations he <a href="http://galton.org/statistician.html">helped to develop</a> the concepts of mean and variation, leading him to formulate the essential statistical concept of standard deviation.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scotland Yard detectives comparing fingerprints" src="https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=419&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=419&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=419&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377067/original/file-20210104-19-129kafb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Scotland Yard detectives pore over fingerprints.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/comparing-fingerprints-in-an-effort-to-identify-a-suspect-news-photo/514900860">Bettmann via Getty Images</a></span>
</figcaption>
</figure>
<p>Galton helped forge a new science of forensics. <a href="https://www.thecrimson.com/article/1968/1/10/confessions-of-a-palmist-pithe-name/">Fortune tellers</a> and others had long scrutinized the lines and creases on the palms and fingers, which had been described in general terms by scientists and physicians. But Galton was the first to suggest that they could be the basis for a new science that he called dermatoglyphics – or “skin carvings.” Galton <a href="https://www.criminaljustice.ny.gov/ojis/history/fp_sys.htm">demonstrated that fingerprints are unique</a>, stable over a lifetime, and could be classified and used to identify individuals who had left prints at the scene of a crime. Scotland Yard adopted his system.</p>
<p>Galton used scientific inquiry to investigate what proponents of religion had long preached was the <a href="https://www.washingtonpost.com/wp-dyn/content/article/2008/12/05/AR2008120502813.html">power of prayer</a>. Reasoning that if prayer works, it should be possible to measure its effects, Galton set out to discover “whether those who pray <a href="http://galton.org/essays/1870-1879/galton-1872-fortnightly-review-efficacy-prayer.html">attain their objects more frequently</a> than those who do not.” In 1872, he published “Statistical Inquiries into the Efficacy of Prayer,” in which he found that prayer produces no measurable difference in outcomes. This conclusion is supported, he argued, by the fact that insurance companies take no interest when setting their rates in whether their clients pray or not.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Galton's first anthropometric laboratory, 1884-1885." src="https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=589&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=589&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377069/original/file-20210104-13-101xbem.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=589&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Galton’s laboratory at the International Health Exhibition at the South Kensington Museum.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/galtons-laboratory-at-the-international-health-exhibition-news-photo/90735101">Science & Society Picture Library via Getty Images</a></span>
</figcaption>
</figure>
<h2>Classifying and enhancing human beings</h2>
<p>Galton founded the field that became known as psychometrics, the measurement of psychological faculties such as intelligence. One of Galton’s most famous works is “Hereditary Genius” (1870), in which he argues “each generation has enormous power over the <a href="https://www.branchcollective.org/?ps_articles=rebecca-n-mitchell-francis-galtons-hereditary-genius-1869-1892">natural gifts of those that follow</a>.” If people would only direct a fraction of the time they spend on improving on cattle to the human race, he lamented, “what a galaxy of genius might we not create!”</p>
<p>Galton credited reading his cousin Charles Darwin’s “On the Origin of Species” (1859) about the <a href="https://www.nationalgeographic.org/encyclopedia/natural-selection/">theory of natural selection</a> with initiating him into “<a href="https://www.darwinproject.ac.uk/francis-galton">an entirely new province of knowledge</a>,” paving the way for his studies of inheritance.</p>
<p>In 1884, Galton set up an “<a href="http://galton.org/anthropologist.htm">Anthropometric Laboratory</a>” at the International Health Exhibition in London. There he collected data on the physical characteristics and abilities of visiting members of the public. They paid to be measured, and he provided them with a copy of their data. He believed that such data could be used to compare individuals across different places of origin, residences, occupations, races and so on.</p>
<p>It was Galton who <a href="https://www.facinghistory.org/resource-library/origins-eugenics">coined the term eugenics</a>, from the Greek for “good stock.” He argued that the tendency of successful families to have few children relatively late in life was “dysgenic,” or bad for the stock, while capable people should be given incentive to marry early and have many children.</p>
<p>Galton thought he had discovered principles that would enhance human life, and he also spoke against what he regarded as “unreasonable” opposition to “the extinction of an inferior race.”</p>
<p>He himself had been born in 1822 into a prominent British family. He was a grandson of Erasmus Darwin, a physician, scientist and prominent abolitionist, and his family included multiple fellows of the Royal Society. His position of privilege likely influenced both his willingness to classify humankind into groups and his sense of what counted as good stock versus what sort of person belonged to an inferior race.</p>
<h2>Long legacy of Galton’s eugenics</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="photo of Galton circa 1890" src="https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=750&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=750&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=750&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=943&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=943&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377070/original/file-20210104-21-1h959ul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=943&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Galton, around 1890.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/francis-galton-british-man-of-science-born-in-sparkbrook-ca-news-photo/526673778">adoc-photos/Corbis Historical via Getty Images</a></span>
</figcaption>
</figure>
<p>Sir Francis Galton died in the U.K. on Jan. 17, 1911, but his work shaped government policies on both sides of the Atlantic for decades. Eugenics policies encouraged the most valued people to procreate in large numbers, while also aiming to prevent reproduction by those considered to be less fit.</p>
<p>Politicians including Theodore Roosevelt expressed the concern that failure of Anglo-Saxons to produce large families would result in “<a href="http://exhibits.hsl.virginia.edu/eugenics/2-origins/">race suicide</a>.” Many states enacted <a href="https://theconversation.com/forced-sterilization-policies-in-the-us-targeted-minorities-and-those-with-disabilities-and-lasted-into-the-21st-century-143144">forced sterilization laws</a>, later backed by a <a href="https://www.npr.org/2017/03/24/521360544/the-supreme-court-ruling-that-led-to-70-000-forced-sterilizations">Supreme Court ruling</a> declaring that “Three generations of imbeciles are enough.”</p>
<p>As ethically faulty as eugenics was, Galton made errors in the science as well. Traits such as intelligence are not the <a href="https://www.nature.com/scitable/topicpage/human-testing-the-eugenics-movement-and-irbs-724/">expression of single genes</a>, and the intelligence of children can differ markedly from that of their parents. Time after time, <a href="https://healthcare.utah.edu/the-scope/shows.php?shows=0_2afdowlt">eugenicists promoted traits</a> such as blond hair and blue eyes that reflected not objectively superior attributes but their own mirror images. The Nazi genocide programs, aimed at promulgating a “<a href="https://www.pbs.org/wgbh/peoplescentury/episodes/masterrace/description.html">master race</a>,” opened many eyes to eugenics’ sinister implications. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>Today Galton’s star has fallen. This past summer, University College London announced that it was <a href="https://www.ucl.ac.uk/news/2020/jun/ucl-denames-buildings-named-after-eugenicists">removing his name from a building</a>, for instance, with his role as the father of eugenics far outweighing his other scientific contributions.</p>
<p>Yet Galton’s legacy has not entirely vanished. It was recently announced that in Europe, the number of babies being born with <a href="https://www.cdc.gov/ncbddd/birthdefects/downsyndrome.html">Down syndrome</a> has <a href="https://www.sciencedaily.com/releases/2020/12/201218131911.htm">fallen by half</a>, the result of prenatal testing and selective pregnancy termination. People are still choosing who can and cannot be born based on genes.</p><img src="https://counter.theconversation.com/content/144465/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Gunderman does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Smart people can have really bad ideas – like selectively breeding human beings to improve the species. Put into practice, Galton’s concept proved discriminatory, damaging, even deadly.Richard Gunderman, Chancellor's Professor of Medicine, Liberal Arts, and Philanthropy, Indiana UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1513602020-12-14T19:02:05Z2020-12-14T19:02:05ZThe evolution of fairness will drive the distribution of COVID-19 vaccines, for better or worse<figure><img src="https://images.theconversation.com/files/374463/original/file-20201211-17-16upga7.jpg?ixlib=rb-1.1.0&rect=18%2C9%2C6020%2C4001&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Governments will need to determine how best to allocate COVID-19 vaccinations.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>As COVID-19 vaccines are approved, the world faces daunting distribution challenges. The top-of-mind question for many is one of fairness: <a href="https://globalnews.ca/news/7468036/canada-coronavirus-vaccine-rollout/">who should get a vaccine first</a>? Today’s fervent debates about an equitable vaccine rollout should not be surprising. </p>
<p>To meet the challenges of group living, humans have evolved a desire for fairness over the last million years. The peculiarities of this evolved desire can have an impact on our decision-making in unfortunate ways, including in how we distribute a vaccine.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/LVUlM8Od9-I?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">CBC The National looks at the debates related to the vaccination rollout plan.</span></figcaption>
</figure>
<h2>Co-operation and human evolution</h2>
<p>Humans are exceptionally co-operative animals. We are the only species that routinely chooses to help others and reacts strongly to <a href="http://doi.org/10.1126/science.1251776">perceived injustice</a>. Our desire to find fair solutions to co-operative dilemmas presents a vexing evolutionary problem.</p>
<p>Evolution through natural selection favours animals that look after <a href="https://doi.org/10.1016/0022-5193(64)90038-4">their own self-interest</a>. In theory, humans should therefore only routinely work with close family members since those who choose to help others will die out. Yet our species has flourished by creating ever <a href="https://upcolorado.com/university-press-of-colorado/item/3018-how-humans-cooperate">larger, and more enduring, collectives</a>.</p>
<p>Charles Darwin sought to solve this dilemma by suggesting that highly co-operative groups “<a href="http://darwin-online.org.uk/EditorialIntroductions/Freeman_TheDescentofMan.html">would flourish best and rear the greatest number of offspring</a>.” Although theories on how social groups form are <a href="https://www.discovermagazine.com/the-sciences/e-o-wilsons-theory-of-altruism-shakes-up-understanding-of-evolution">controversial</a>, primatologists and physical anthropologists have pieced together a story of human evolution that hinges on our increasing <a href="https://doi.org/10.1017/S0140525X03220057">ability to work together</a>. </p>
<p>Early humans and our immediate ancestors were slow, weak and lacked claws and fangs. To survive, we slowly developed a social brain built to <a href="https://doi.org/10.1080/03014460902960289">maintain close relationships</a> between highly mobile hunters, gatherers and scavengers. </p>
<p>By the time that <em>Homo sapiens</em> evolved, co-operation would be sustained via <a href="https://www.basicbooks.com/titles/christopher-boehm/moral-origins/9780465020485/">an evolved sense of fairness</a> that favoured both equalizing rewards across a group and punishing selfish behaviour. Selfishness, of course, still exists, but people feel guilty about actions that <a href="https://doi.org/10.1016/j.mehy.2015.03.015">run counter to group interests</a>. Studies confirm that this sense of fairness is <a href="https://global.oup.com/academic/product/why-humans-cooperate-9780195314236">cross-cultural</a> and in place <a href="https://doi.org/10.1111/j.1532-7078.2012.00129.x">before children can even talk</a>.</p>
<h2>Big groups break down</h2>
<p>Darwin was clear that <a href="http://darwin-online.org.uk/EditorialIntroductions/Freeman_TheDescentofMan.html">co-operation had its limits</a>. Being fair to other group members may feel right, but, evolutionarily speaking, we should draw the line when it comes to our interactions with outsiders.</p>
<p>History can be written as a confrontation between <a href="https://www.upress.umn.edu/book-division/books/the-morals-of-history">an “us” and the “other.”</a> My <a href="https://upf.com/book.asp?id=9780813066745">forthcoming book</a> details some of the ways our evolved sense of fairness shaped identity politics over the past 20,000 years.</p>
<p>Larger societies are formed by extending group memberships. If you want to make a few nuclear families into a cohesive unit, then put them together in a larger house or have them participate in a <a href="https://doi.org/10.1080/00438240701249686">shared ritual</a>. If you want people to identify with an empire, grant them citizenship and <a href="https://www.bloomsbury.com/us/the-toga-and-roman-identity-9781472571557/">something special to wear</a>. When people feel they are part of a group, they look out for each other and expect to be treated fairly.</p>
<p>The problem is that people belong to multiple social groups. Larger and more recent groupings tend to be more weakly held, and when times get tough, larger <a href="https://www.penguinrandomhouse.com/books/205014/why-nations-fail-by-daron-acemoglu-and-james-a-robinson/">collectives can break down</a>. These divorces, however, are neither transparent nor finalized. When group memberships get muddled, the “fairest” solutions to a given collective problem become hotly contested. </p>
<h2>Allocating immunity</h2>
<p>In early September, the World Health Organization (WHO) announced its <a href="http://doi.org/10.1126/science.abe8953">plan for global vaccine distribution</a>. Three per cent of each country’s population would initially receive vaccines, with 20 per cent being inoculated in subsequent phases. Although debates on the finer points of a “<a href="http://dx.doi.org/10.1126/science.abe2803">fair and equitable</a>” distribution continue, 172 countries are now in talks to be part of <a href="https://www.who.int/news/item/24-08-2020-172-countries-and-multiple-candidate-vaccines-engaged-in-covid-19-vaccine-global-access-facility">the WHO’s program</a>.</p>
<p>Yet countries remain in competition. As COVID-19 cases rise in many places in the world, countries strike <a href="https://www.theguardian.com/world/2020/nov/03/rich-states-covid-deals-may-deprive-poor-of-vaccine-for-years">their own distribution deals</a> with manufacturers, <a href="https://www.nytimes.com/2020/12/03/world/europe/UK-US-coronavirus-vaccine-nationalism.html">vaccine nationalism</a> is on the rise and nations are wavering in their WHO commitments. </p>
<p>Who should get the vaccine has narrowed to a national conversation. We take care of our own.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Christine Elliott stands at a podium with sign reading THE COVID-19 DISTRIBUTION TASK FORCE" src="https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374462/original/file-20201211-13-1n499jn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ontario Health Minister Christine Elliott answers questions during a briefing in Toronto on Dec. 1, 2020.</span>
<span class="attribution"><span class="source">THE CANADIAN PRESS/Frank Gunn</span></span>
</figcaption>
</figure>
<p>From an evolutionary perspective, the vaccine distribution debate is a new chapter in the same old story. If we repeatedly define our group during the pandemic as the nation-state rather than our global connections, then our feelings on fairness will inevitably follow. We will expect to be treated equitably by our fellow citizens, and expect to be in competition with everyone else.</p>
<p>Can we fairly distribute a COVID-19 vaccine amid fiercely competing states? <a href="https://www.cbc.ca/news/health/covid19-vaccine-nationalism-1.5752898">It seems unlikely</a>. Although a better distribution plan or a more heartfelt appeal to assist others might help, driving home the message that the world is in this together would engage with our instinct to help fellow group members. </p>
<p>If we think globally, fairness will follow.</p><img src="https://counter.theconversation.com/content/151360/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Justin Jennings receives funding from the Social Sciences and Humanities Research Council of Canada, National Geographic Society, Royal Ontario Museum, and University of Toronto.</span></em></p>When allocating resources, we prioritize members of the social groups we belong to, rather than including others in our allocations. This will determine how the COVID-19 vaccine is distributed.Justin Jennings, Associate Professor, Anthropology, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1508252020-12-14T13:20:34Z2020-12-14T13:20:34ZW.E.B. Du Bois embraced science to fight racism as editor of NAACP’s magazine The Crisis<figure><img src="https://images.theconversation.com/files/373656/original/file-20201208-21-huflu9.png?ixlib=rb-1.1.0&rect=17%2C17%2C2243%2C1613&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">W.E.B. Du Bois in his office at The Crisis in New York City, 1925.</span> <span class="attribution"><a class="source" href="http://credo.library.umass.edu/view/full/mums312-i0421">W. E. B. Du Bois Papers (MS 312). Special Collections and University Archives, University of Massachusetts Amherst Libraries</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>The NAACP – the most prominent interracial civil rights organization in American history – published the first issue of The Crisis, <a href="https://www.thecrisismagazine.com">its official magazine</a>, 110 years ago, in 1910. For almost two and a half decades, sociologist and civil rights activist W.E.B. Du Bois served as its editor, famously using this platform to dismantle scientific racism. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Yellowed print ad for The Crisis with photo of a young Black child and text." src="https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=853&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=853&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=853&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1072&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1072&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373621/original/file-20201208-20-w8p2rq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1072&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An advertisement for The Crisis, circa March 1925.</span>
<span class="attribution"><a class="source" href="https://credo.library.umass.edu/view/full/mums312-b170-i549">W.E.B. Du Bois Papers (MS 312). Special Collections and University Archives, University of Massachusetts Amherst Libraries</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>At the time, many widely respected <a href="https://doi.org/10.1086/211280">intellectuals gave credence to beliefs</a> that empirical evidence exists to justify a “natural” white superiority. Tearing down scientific racism was thus a necessary project for The Crisis. Under Du Bois’ leadership, the magazine laid bare the irrationality of scientific racism. </p>
<p>Less remembered, however, is how it also sought to help its readers understand and engage with contemporary science. </p>
<p>In nearly every issue, the magazine reported on scientific developments, recommended scientific works or featured articles on natural sciences. Du Bois’ time as editor of The Crisis was just as much about critically embracing careful, systematic, empirical science as it was about skewering the popular view that Blacks (and other nonwhites) were naturally inferior. </p>
<p>Sociologists <a href="https://as.vanderbilt.edu/sociology/bio/?who=patrick-greiner">Patrick Greiner</a> and <a href="https://faculty.utah.edu/u0847751-BRETT_CLARK/hm/index.hml">Brett Clark</a> <a href="https://arts-sciences.buffalo.edu/sociology/faculty/faculty-directory/besek-jordan.html">and I</a> recently pored through the magnificent <a href="https://credo.library.umass.edu/view/collection/mums312">W.E.B. Du Bois Papers</a> at the Special Collections and University Archives at the University of Massachusetts Amherst. <a href="https://doi.org/10.1177/1468795X20938624">We found that Du Bois not only drew from natural sciences</a>, but thought deeply about the ways in which The Crisis should and should not do so. He would even go so far as to critique allies for using science in ways he thought inappropriate.</p>
<h2>Case in point: Defending Darwin</h2>
<p>On Feb. 18, 1932, the Harlem pastor Adam Clayton Powell wrote to Du Bois, asking him to publish his recent address at a NAACP mass meeting in an upcoming issue of The Crisis.</p>
<p>A week later, <a href="http://credo.library.umass.edu/view/full/mums312-b192-i371">Du Bois responded</a> that while he’d read Powell’s address “with great interest,” he could not publish it as written. Why? It got biologist Charles Darwin and his theory of natural selection very wrong. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="excerpt of typewritten letter on yellowed paper" src="https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=286&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=286&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=286&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=359&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=359&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373628/original/file-20201208-23-1ibsv7w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=359&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An excerpt of Du Bois’ letter of Feb. 25, 1925 to Adam Clayton Powell.</span>
<span class="attribution"><a class="source" href="https://credo.library.umass.edu/view/full/mums312-b192-i371">W.E.B. Du Bois Papers (MS 312). Special Collections and University Archives, University of Massachusetts Amherst Libraries</a></span>
</figcaption>
</figure>
<p>Darwin, explained Du Bois, did not try to demonstrate “who ought to survive,” as Powell’s address assumed. Rather, Darwin’s work is “simply a scientific statement” that had been twisted to support eugenicist and other pseudo-scientific doctrines. </p>
<p>This short reply to the powerful pastor contains so much. It shows that Du Bois demanded a nuanced appreciation of Darwin’s theory of natural selection. Further, he insisted Darwin should not be held liable for the racist ideologues who misappropriated his work, cloaking their demagoguery in scientific objectivity. Darwin’s work is of clear value, but one must always remain aware that, like with all science, politics shaped its reception.</p>
<p>For Du Bois, how one understands and uses science were not minor issues. </p>
<h2>Science in The Crisis</h2>
<p>In the first section of <a href="https://modjourn.org/issue/bdr507789/">the first issue of The Crisis</a>, there is an archaeological report. It describes how “exploration of the African continent is yet in its infancy and will doubtless yield surprising results in establishing the advanced state of development attained by the black races in early times.” </p>
<p>According to the latest archaeology, in other words, African heritage is something to be proud of. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Subheading 'SCIENCE' above a column of text." src="https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=210&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=210&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=210&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=264&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=264&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373640/original/file-20201208-18-1w0t65r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=264&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">On page 6 of the inaugural issue of The Crisis, a subheading for ‘SCIENCE.’</span>
<span class="attribution"><a class="source" href="https://modjourn.org/issue/bdr507789/">The Crisis. Vol. 1, No. 1; 1910. The Modernist Journals Project. Brown and Tulsa Universities, ongoing. www.modjourn.org</a></span>
</figcaption>
</figure>
<p>Later in that issue, under the subheading “Science,” it is noted that a paper was read before the British Association for the Advancement of Science concluding that “all earlier human races were probably colored.” This same section notes a recent study providing evidence that, in a direct rebuke to scientific racism, “mere brain weight is no indication of mentality.”</p>
<p>In the second issue of The Crisis, the famed Columbia University anthropologist Franz Boas explained that there is no physical anthropological evidence “<a href="https://modjourn.org/issue/bdr507810/">showing inferiority of the Negro race</a>.” Later issues would highlight early African metallurgy and critique racist intelligence tests. Another would <a href="https://modjourn.org/issue/bdr507921/">recommend a work by Peter Kropotkin</a>, the great Russian anarchist and zoologist, which suggested that natural selection is more about cooperation among species than any fight for survival between them.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Article headlined 'Is the Negro Inferior?'" src="https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=255&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=255&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=255&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=321&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=321&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373652/original/file-20201208-20-8ogeie.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=321&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Crisis published articles by prestigious scholars who drew on science to refute racism.</span>
<span class="attribution"><a class="source" href="https://books.google.com/books?id=AVgEAAAAMBAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">The Crisis, Nov. 1932</a></span>
</figcaption>
</figure>
<p>The Crisis published this sort of work throughout Du Bois’ time as editor. The reason why is clear. Du Bois knew that a proper understanding of science does not lead to biological essentialism – the idea that biology limits who you are and what you can do. It leads to the exact opposite conclusion, that every population has the ability to make their own meaning and determine themselves as they see fit. The only constraints are social processes like colonialism and racism. Science, for Du Bois, was in this way necessary and liberating.</p>
<h2>Science for an emancipated politics</h2>
<p>Today’s political moment is different than Du Bois’, though there are some parallels. One is that a political life free of exploitation and enhanced by participatory democracy remains out of reach for many. Disenfranchisement still exists in many forms. As the Black Lives Matter movement and others have shown, racism is a big reason why.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="W.E.B. Du Bois in his office, ca. 1948" src="https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=688&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=688&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=688&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=864&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=864&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373659/original/file-20201208-22-1wfq5kt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=864&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">W.E.B. Du Bois in his office, ca. 1948, holding the first issue of The Crisis.</span>
<span class="attribution"><a class="source" href="http://credo.library.umass.edu/view/full/mums312-i0463">W.E.B. Du Bois Papers (MS 312). Special Collections and University Archives, University of Massachusetts Amherst Libraries</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>While only a piece of the puzzle, Du Bois’ insistence on critically embracing a careful, systematic and empirical view of science can be an important part of that struggle for an emancipated politics. A critical embrace of science can help people better tackle pressing issues like environmental justice, health care disparities and more. </p>
<p>To critically embrace science is to, as Du Bois did in the pages of The Crisis, remain unwavering in the fact that any scientific theory promoting racial and other forms of injustice is categorically wrong.</p>
<p>He demonstrated how to reject racist science without rejecting the ways that science can help people better understand our relationships with the world. In particular, engaging science shows how our relationships with each other are not determined by nature, but are under our own control.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p><img src="https://counter.theconversation.com/content/150825/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jordan Besek does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As editor of the magazine for 24 years, Du Bois featured articles about biology, evolution, archaeology in Africa and more to refute the rampant scientific racism of the early 20th century.Jordan Besek, Assistant Professor of Sociology, University at BuffaloLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1445322020-10-02T13:23:47Z2020-10-02T13:23:47ZEvolution on the smallest of scales smooths out the patchwork patterns of where plants and animals live<figure><img src="https://images.theconversation.com/files/361176/original/file-20201001-14-zoiiee.png?ixlib=rb-1.1.0&rect=0%2C25%2C1888%2C985&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In the Pacific Northwest, even though there are huge variations in environment, the Douglas fir grows everywhere.</span> <span class="attribution"><a class="source" href="https://images.nasa.gov/details-GSFC_20171208_Archive_e001450">NASA/NOAA</a></span></figcaption></figure><p>The Douglas fir is a tall iconic pine tree in Western North America forming a forest that winds unbroken from the Western spine of British Columbia all the way to the Mexican cordillera. The environmental conditions of Canada and Mexico are obviously very different, but even on much smaller scales – say, the top of a mountain compared with a valley below it – the rainfall, temperature, soil nutrients and dozens of other factors can vary quite a bit. The Douglas fir grows well in so many of these places that it turns a dramatically varied landscape into one smooth, continuous forest complete with all the species it supports. </p>
<p><a href="https://scholar.google.com/citations?user=8aJp2VQAAAAJ&hl=en&oi=ao">I am an ecologist</a> and used to think that the Douglas fir was simply a hardy tree, rarely hemmed in by environmental conditions or other species. But recent research done by my colleagues and me suggests that environmental conditions are not all that determines where plants and animals live in a landscape and the patchwork patterns of those distributions. These spatial patterns are also <a href="https://doi.org/10.1073/pnas.1918960117">influenced by evolution</a>.</p>
<p>Over time, species often <a href="https://doi.org/10.1111/j.1461-0248.2004.00684.x">adapt to local conditions</a>, and these adaptations alter how and where they can live. For example, Douglas fir trees might adapt through evolution to thrive on both a dry mountainside and in a wet valley nearby. But my colleagues and I have taken this idea a step further to explore not just how organisms adapt, but how the process of adaptation itself can have profound effects on the patterns of where organisms live in a landscape.</p>
<p>Without adaptation, you might find a mixed patchwork of where species live – a species of insect lives in the valley, but not on the mountains. When Douglas firs adapt to and grow on a dry mountain as well as in the wet valley, they create one continuous forest habitat where two very different landscapes used to exist. The birds, the insects, the deer, the flowers and all the other organisms that live in the forest can also now occupy both the valley and the mountaintop. Adaptation by the Douglas fir created a smoother distribution of species.</p>
<p>Adaptation, it seems, plays a larger role in <a href="https://doi.org/10.1073/pnas.1918960117">determining ecological patterns</a> than scientists previously thought.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A blue salamander with yellow spots sitting on a moss-covered log." src="https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361183/original/file-20201001-22-3l15li.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Yellow-spotted salamanders in some ponds get eaten by larger predators, but in others, they adapted to eat more and grow quickly so that they would not be eaten.</span>
<span class="attribution"><a class="source" href="http://hydrodictyon.eeb.uconn.edu/people/urban/">Mark Urban</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>A salamander mystery</h2>
<p>In 1999, when I was a beginning graduate student in Connecticut, I wanted to understand how a predator called the marbled salamander affected the survival of the smaller yellow-spotted salamander in small temporary ponds. Much like the famous <a href="https://doi.org/10.1016/j.biocon.2011.11.005">wolves in Yellowstone National Park</a>, the marbled salamander is a <a href="https://www.nature.com/scitable/knowledge/library/keystone-species-15786127/">keystone predator</a>, and just a few individuals in a pond can determine which other species live there.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A marbled salamander floating under the surface of the water." src="https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361177/original/file-20201001-13-175mmwi.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Marbled salamanders are keystone predators in New England ponds, but adaptation by the smaller spotted salamander can dramatically change the composition of the ponds.</span>
<span class="attribution"><a class="source" href="http://hydrodictyon.eeb.uconn.edu/people/urban/">Mark Urban</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>I spent months watching these ponds, but however much I tried, the patterns I saw just weren’t making sense. In one pond, the yellow-spotted salamanders survived alongside the marbled predator. But in the next pond over, under nearly identical conditions, the spotted salamanders were quickly reduced to predator poop. I couldn’t find an environmental explanation for this.</p>
<p>To figure out what was driving this unevenness of high and low survival, I collected salamander eggs from ponds where the small salamanders survived alongside the predator, as well as eggs from ponds without predators. I then raised these yellow-spotted salamanders in buckets and looked for differences between them.</p>
<p>I found one surprising difference. The salamanders from ponds with the predatory marbled salamander adapted to the predator by becoming gluttonous – eat and get big <a href="https://doi.org/10.1073/pnas.0704645104">so you don’t get eaten yourself</a>. </p>
<p>In these little New England ponds, local adaptation had created spotted salamander populations with very different behaviors to allow them to survive predation from the marbled salamander. But before I could find out more, I finished my doctorate and found myself driving far away from these salamanders to a new job in California. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dark gray salamander with black splotches sitting atop a fallen leaf." src="https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361178/original/file-20201001-22-1u4vej9.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Marbled salamanders were causing local adaptation in another species that was driving dramatic differences in ponds.</span>
<span class="attribution"><a class="source" href="http://hydrodictyon.eeb.uconn.edu/people/urban/">Mark Urban</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Adaptation, not environment, as a cause?</h2>
<p>Over the next few years, other ecologists were beginning to recognize that <a href="https://doi.org/10.1038/nature01767">evolution could happen very quickly</a>. In one classic experiment, scientists put algae and a microscopic grazer into a tank together. At first, there were cycles of boom and bust, but after only a few weeks, the algae evolved defenses that prevented them from being eaten and stopped the large swings in population numbers. </p>
<p>This was intriguing. My experience with the salamanders had taught me that evolution could happen not just quickly, but also differently in two nearby and otherwise similar ponds. If evolution affected population patterns in time, maybe it could also affect species distribution patterns in space.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Rows of large black cattle tanks." src="https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361179/original/file-20201001-14-12ncz4t.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Large cattle watering tanks make for effective experimental ponds.</span>
<span class="attribution"><a class="source" href="http://hydrodictyon.eeb.uconn.edu/people/urban/">Mark Urban</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>I returned to my salamanders after getting a job at the University of Connecticut. This time, I wasn’t interested just in how salamanders adapted to their ecosystem, but how their adaptations altered the ecosystem itself. I again raised salamanders from high- and low-predation ponds under the same conditions. But this time, I tracked what happened to other species in the artificial ecosystems I had created.</p>
<p>The predatory marbled salamanders eat small crustaceans. But the yellow–spotted salamanders adapted to the predators by eating more of these small crustaceans too. Adaptation by the yellow-spotted salamanders resulted in far fewer crustaceans in the ponds. My experiment showed that this adaptation <a href="https://doi.org/10.1098/rspb.2013.0859">amplified differences in the numbers of crustaceans</a> between ponds with and without the marbled predator. In this case, adaptation made two ponds more different than they would have been otherwise.</p>
<p>When I compared my experiments with what was happening in the natural ponds, I realized that I had discovered what was driving the perplexing patterns I’d seen years before. Local adaptation, not just the environment or other species, was amplifying the differences in these ponds. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Looking down into a canyon in southern Utah filled with Douglas fir trees." src="https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361180/original/file-20201001-16-2hsi2t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Just like the salamanders, Douglas firs undergo local adaptation that drives broad changes in where organisms live.</span>
</figcaption>
</figure>
<h2>Adaptation as a universal effect</h2>
<p>I began to wonder: If this effect was happening with salamanders, could local adaptation also amplify or dampen spatial ecological patterns in other species? Was this a widespread effect?</p>
<p>Answering this question would require evidence from creatures all around the world. I recruited a bunch of biologist friends to help me sort through thousands of past studies on everything from <a href="https://doi.org/10.1111/evo.12594">bacteria</a> to <a href="https://doi.org/10.2307/2409129">birds</a> and look for evidence that local adaptation was changing the spatial patterns of these species.</p>
<p>Our team gathered information from 500 studies over the past 100 years. We found that, as with my salamanders, adaptation sometimes makes existing differences between places <a href="https://doi.org/10.1073/pnas.1918960117">even greater than expected without evolution</a>.</p>
<p>Adaptation can also create patterns where none existed previously. Widespread plants like goldenrods and aspens often evolve chemical defenses that change which insects can eat them. Adaptation creates new patchwork patterns of <a href="https://doi.org/10.1007/BF00328428">insect abundances and diversity across fields and forests</a> where none would exist otherwise. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>However, we found that in 85% of cases, adaptation <a href="https://doi.org/10.1073/pnas.1918960117">dampened existing ecological spatial patterns</a>. Organisms ranging from the modest apple maggot fly to the grand Douglas fir adapted in ways that reduced the variability of the landscapes in which they lived. Adaptation on small spatial scales smoothed out the patchwork of forests and meadows, populating both hilltops and valleys with the same trees, birds, insects and other organisms. Thanks to adaptation, the world in general is more homogeneous than it would otherwise be.</p>
<p>So next time you find yourself counting down the hours for your car to reach its destination, notice the natural patterns scrolling by your window. Many of these patterns reflect the hidden hand of evolution, which has ironed out the wrinkles and left the world a smoother place.</p><img src="https://counter.theconversation.com/content/144532/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark C Urban receives funding from the U.S. National Science Foundation. </span></em></p>Local adaptation allows plants and animals to thrive in a diversity of places. Sometimes adaptation sharpens patterns of where organisms live, but 85% of the time, it creates a more homogeneous world.Mark C. Urban, Director, Center of Biological Risk; Professor of Ecology and Evolutionary Biology, University of ConnecticutLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1320552020-02-26T11:28:15Z2020-02-26T11:28:15ZThe eugenics debate isn’t over – but we should be wary of people who claim it can fix social problems<figure><img src="https://images.theconversation.com/files/316881/original/file-20200224-24685-1khngqd.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C2901&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/genetic-engineering-gene-manipulation-concept-hand-607718810">vchal/Shutterstock</a></span></figcaption></figure><p>Andrew Sabisky, a UK government adviser, <a href="https://www.theguardian.com/politics/2020/feb/17/boris-johnson-adviser-quits-over-race-and-eugenics-writings">recently resigned</a> over comments supporting eugenics. Around the same time, the evolutionary biologist Richard Dawkins – best known for his book The Selfish Gene – provoked controversy when <a href="https://twitter.com/RichardDawkins/status/1228943686953664512">tweeting</a> that, while eugenics is morally deplorable, it “would work”. </p>
<p>Eugenics can be described as the science and practice of improving the human race through the selection of “good” hereditary traits. Eugenics inevitably brings to mind the atrocities committed by the Nazis, who used eugenic ideology as the rationale for large-scale forced sterilisation, involuntary euthanasia and the Holocaust. Given this sinister history, it’s bound to be alarming when government officials endorse eugenic ideas.</p>
<p>The eugenics movement of the past has been thoroughly discredited on both moral and scientific grounds. But questions about the ethics of genetically improving humans remain relevant.</p>
<p>The emergence of new genetic technologies often prompts renewed debate. Can eugenic ideas about improving the human race be divorced from the evils of the past and pursued through benign means? Or is there something inherently morally problematic about the idea of genetically improving humans?</p>
<p>A new, morally responsible eugenics may well be <a href="https://www.cambridge.org/core/journals/cambridge-quarterly-of-healthcare-ethics/article/why-we-should-defend-gene-editing-as-eugenics/00B15AEB625379F8543C43E286160B87">defensible</a>, and new genetic technologies must be assessed on their own terms. But we also need to consider the broader political context. If the betterment of individual traits were to be presented as a key strategy to improve human welfare, this would look very much like the individualisation of social problems that was such a central feature of the old eugenics. </p>
<h2>Dark past</h2>
<p>The father of the eugenics movement was the English explorer and scientist <a href="https://www.cambridge.org/core/journals/british-journal-for-the-history-of-science/article/from-political-economy-to-sociology-francis-galton-and-the-socialscientific-origins-of-eugenics/D554ED0C9027F4E646D072C664529F2F">Francis Galton</a> (1822-1911). Influenced by his cousin Charles Darwin’s work The Origin of Species, Galton was interested in ideas about the heritability of different traits. He was particularly interested in the heritability of intelligence and how to increase society’s diminished stock of talent and character. He also believed that social problems such as poverty, vagrancy and crime were ultimately caused by the inheritance of degenerate traits from parent to child.</p>
<p>Galton embarked on an ambitious research programme with the explicit goal to “improve human stock” through selective human breeding. <a href="https://www.cambridge.org/core/journals/british-journal-for-the-history-of-science/article/from-political-economy-to-sociology-francis-galton-and-the-socialscientific-origins-of-eugenics/D554ED0C9027F4E646D072C664529F2F">In 1883</a> he named this research programme “eugenics”, meaning “good in birth”.</p>
<p>Galton’s ideas quickly became influential and were widely embraced, first in Britain but subsequently in many other countries, including the US, Germany, Brazil and Scandinavia. At a time coloured by widespread concerns about the state of the nation, lack of social progress and the “degeneration” of the population, Galton’s ideas inspired a popular movement for social reform through selective human reproduction.</p>
<p>The first half of the 20th century saw the enactment of a variety of eugenic policies. “Positive” eugenics focused on encouraging those of “good stock” to reproduce, such as through the “fitter family” contests put on across the US. “Negative” eugenics involved discouraging or preventing reproduction among those deemed “unfit”, such as the poor, criminals or the “feeble-minded”, predominantly by coercive means. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/316887/original/file-20200224-24690-uptmqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316887/original/file-20200224-24690-uptmqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=473&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316887/original/file-20200224-24690-uptmqg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=473&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316887/original/file-20200224-24690-uptmqg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=473&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316887/original/file-20200224-24690-uptmqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=595&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316887/original/file-20200224-24690-uptmqg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=595&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316887/original/file-20200224-24690-uptmqg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=595&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Eugenics Fitter Families contest winners in Topeka, Kansas.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/w/index.php?curid=30135414">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Eugenics is often equated with Nazi atrocities, but many other brutal acts were committed in its name, usually targeting disadvantaged and vulnerable groups, such as the poor, disabled and ill. As part of the negative eugenic effort, forced sterilisation was conducted on a large scale, not only in Nazi Germany but also in the Scandinavian countries (in <a href="http://news.bbc.co.uk/1/hi/health/background_briefings/international/290661.stm">Sweden</a>, this practice continued until the 1970s) and in the US (where it was revealed that <a href="https://www.theguardian.com/commentisfree/2013/nov/08/california-female-prisoner-sterilization">involuntary sterilisation of female prisoners</a> occurred as late as 2010). The US combined eugenic ideology with ideas about racial hierarchy and applied eugenic thinking to immigration. This led to the passing of the 1924 Immigration Restriction Act in order to curb the entry of “inferior” ethnic groups.</p>
<h2>New genetic technologies</h2>
<p>After the second world war and the exposure of the Nazi regime’s atrocities, eugenics fell out of favour. But worries about eugenics often resurface with the introduction of new genetic technologies that allow us to “improve” humans in some way, most notably gene editing, such as <a href="https://ghr.nlm.nih.gov/primer/genomicresearch/genomeediting">CRISPR-Cas9</a>, and reproductive technologies, such as <a href="https://www.hfea.gov.uk/treatments/embryo-testing-and-treatments-for-disease/pre-implantation-genetic-diagnosis-pgd/">pre-implantation genetic diagnosis</a>. Reproductive technologies mainly help prospective parents to have children free from genetically based disabilities and disorders, but as our knowledge of the human genome advances, the range of traits we may be able to select away or select for will probably increase, prompting fears of “designer babies”.</p>
<p>Such technologies are sometimes labelled “eugenic” by sceptics as a means to discredit them. Arguments then ensue about whether these technologies represent a form of “old” eugenics and are therefore unethical, or whether they represent a “new”, benign form of eugenics. Questions about the ethics of genetic technologies and the new eugenics are far from settled.</p>
<p>But even if our ethical analysis should deem such new genetic technologies permissible, it would be disingenuous to present these technological advances as “solutions” to complex problems such as poverty, unemployment, or poor physical or mental health. We should be wary of biological determinist narratives that blame various forms of disadvantage on individual traits, without acknowledging the importance of social and political factors. This kind of thinking is very much in line with the old eugenics.</p>
<p>We are right to be worried when government officials endorse eugenic ideas. It is reassuring that Sabisky’s comments provoked such outrage and that he was forced to resign. But in some respects, in the current age of austerity policies, the individualisation of social problems is an all too familiar theme.</p><img src="https://counter.theconversation.com/content/132055/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gry Wester does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>CRISPR isn’t a tool to fix social problems.Gry Wester, Lecturer in Bioethics and Global Health Ethics, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1276642020-01-28T17:52:18Z2020-01-28T17:52:18ZHow Darwin’s sexual selection theory co-stars in ‘The Handmaid’s Tale’<figure><img src="https://images.theconversation.com/files/311680/original/file-20200123-162194-13sgd8u.jpg?ixlib=rb-1.1.0&rect=29%2C119%2C4962%2C3128&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The role of women in futuristic drama TV series 'The Handmaid's Tale' makes references to Darwin's writings on evolution.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p><em>The Handmaid’s Tale</em> is a TV series based on the <a href="https://www.penguinrandomhouse.com/books/6125/the-handmaids-tale-by-margaret-atwood/">1985 novel of the same name by Margaret Atwood</a> that presents a dystopian vision of a male-dominated society known as Gilead.</p>
<p>Widespread infertility means that the few fertile women who remain have been enslaved as handmaids and assigned to Gilead’s leaders to produce their future offspring. The series follows the struggles of June, who was separated from her family and forced to become a handmaid.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RcTvQx1Wot0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A trailer for the third season of The Handmaid’s Tale.</span></figcaption>
</figure>
<p>But just what is a reference to the evolutionist Charles Darwin doing in an episode of <em>The Handmaid’s Tale</em>?</p>
<p>As a historian of science currently writing a book on the Darwinian Revolution, I am intrigued by Darwin’s connection with this fictional society. </p>
<p>The reference may have something to do with Darwin’s chief evolutionary mechanism: <a href="https://plato.stanford.edu/entries/natural-selection/">natural selection or the survival of the fittest</a>. But we’ll see that Darwin’s inclusion in <em>The Handmaid’s Tale</em> actually relates to his less well-known and secondary evolutionary mechanism, <a href="https://www.darwinproject.ac.uk/commentary/evolution/sexual-selection">sexual selection</a>.</p>
<h2>‘Women can be useful’</h2>
<p>The third episode of season 3, titled “Useful,” finds June assigned to Joseph Lawrence, a high-ranking commander in Gilead. As Lawrence hosts a meeting of Gilead’s leaders in his drawing room, the men discuss what to do about recently captured female insurgents. </p>
<p>Should they be forced into hard labour in the Colonies or be publicly executed? Commander Lawrence, however, finds neither of these options appealing. The realities of the widespread infertility that spurred the regime’s existence suggests that some of the intransigent women might be useful after all.</p>
<p>Lawrence then tells June to get a book from his bookcase that will help the leadership group better understand “an individual’s value in the world as it pertains to gender.” The book in question is Charles Darwin’s <a href="https://www.bl.uk/collection-items/the-descent-of-man-by-darwin"><em>Descent of Man</em></a>, which Lawrence calls “an oldie but a goodie.” </p>
<p>After June hands the book to Lawrence, he then exclaims to his powerful guests: “See? Women can be useful.”</p>
<h2>Darwin’s theory of sexual selection</h2>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=988&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=988&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=988&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1242&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1242&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311676/original/file-20200123-162185-1a7i68b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1242&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Title page of ‘The Descent of Man’ by Charles Darwin (London, John Murray, 1875).</span>
<span class="attribution"><span class="source">Wellcome Collection</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Far from being a throwaway remark, the reference to Darwin’s <em>Descent of Man</em> in this scene is highly suggestive. While Darwin’s 1859 <a href="http://darwin-online.org.uk/EditorialIntroductions/Freeman_OntheOriginofSpecies.html"><em>On the Origin of Species</em></a> is much more widely read and appreciated as establishing evolution as a science, Darwin did not write specifically about human evolution until 1871 when <a href="http://darwin-online.org.uk/contents.html#descent"><em>The Descent of Man and Selection in Relation to Sex</em></a> was published. In this book, Darwin put forward his theory of sexual selection.</p>
<p>Today, Darwin’s theory of sexual selection is often used to explain the bright and brilliant plumage typical of male birds of paradise, along with their often bizarre mating rituals meant to entice females. While Darwin spent several chapters discussing the esthetic senses of birds that led to such interesting evolutionary adaptations, he did not limit his application of sexual selection to birds alone.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/311678/original/file-20200123-162216-luienz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Darwin explained the ostentatious displays of male birds - like this lesser bird-of-paradise - as a way to attract females and ensure genetic continuation.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Science historian Evelleen Richards explains that Darwin believed that his theory of sexual selection could <a href="https://www.press.uchicago.edu/ucp/books/book/chicago/D/bo25338514.html">account for important aspects of human evolution as well, such as the physical and mental distinctions between men and women</a>. </p>
<p>As Richards shows, when it came to issues of gender (and race for that matter), Darwin was very much a man of his time, and this fact shaped his evolutionary views. He argued that <a href="https://www.icr.org/article/darwins-teaching-womens-inferiority/">there was a vast distinction between the intellectual capabilities of men and women, believing that men were ultimately superior</a>:</p>
<blockquote>
<p>“The chief distinction in the intellectual powers of the two sexes is shewn by man attaining to a higher eminence, in whatever he takes up, than woman can attain — whether requiring deep thought, reason or imagination, or merely the use of the senses and hands.”</p>
</blockquote>
<p>This distinction could be explained, according to Darwin, by the fact that men had to struggle against one another in the contest for mates, whereas women were largely passive. Through this struggle, men acquired certain intellectual capabilities late in their development, capabilities that were then only passed on to male offspring. </p>
<p>Because of this, the mental state of women was arrested in time and “characteristic,” as Darwin put it, “of the lower races, and therefore of a past and lower state of civilization.”</p>
<h2>Embracing maternity</h2>
<figure class="align-right zoomable">
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<span class="caption">Commander Joseph Lawrence is played by the actor Bradley Whitford; in the show, Commander Lawrence is a high-ranking official.</span>
<span class="attribution"><a class="source" href="https://www.hulu.com/press/actor/bradley-whitford/?show_id=1132">(Hulu Press)</a></span>
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<p>It followed for Darwin that it would be a waste of resources to bring women up to the intellectual level of men. Women should, therefore, fully embrace their maternal instincts, raise children and establish happy homes. </p>
<p>Darwin’s wife Emma did exactly that, creating a comfortable home for Darwin to pursue his scientific endeavours while giving birth to 10 children, <a href="https://www.darwinproject.ac.uk/emma-darwin">with the last one born when she was 48 years old</a>.</p>
<p>In many ways, <em>The Handmaid’s Tale</em> presents a society that is reduced to the gender stereotypes that were inscribed in Darwin’s theory of sexual selection. Women are useful only in so far as they can reproduce. And those who can, like June, are essentially made sexual slaves to the powerful. Men, meanwhile, are physically and intellectually in control of the levers of power. </p>
<p>When Commander Lawrence tells June to get <em>Descent of Man</em> from the bookshelf, he is reminding her that she can be useful, but only from within the narrow sphere defined by her biology. <em>The Handmaid’s Tale</em>, of course, is ultimately critical of such gender determinism, as the development of June herself makes clear. </p>
<p>But the politics of biology is not just a relic of the 19th century or the product of science fiction. Philosopher Cordelia Fine shows that <a href="https://www.wwnorton.co.uk/books/9780393082081-testosterone-rex">there are still many evolutionary scientists who hold that the inequality between the sexes is natural, not cultural</a>. </p>
<p>On the surface, therefore, Gilead may look like an unrealistic society that chose to embrace its most extreme views about gender in order to survive. But the brilliance of <em>The Handmaid’s Tale</em> is in showing that many of those views, in certain contexts, are actually not so radical, and can even be found in classic biology texts. </p>
<p>This all suggests that the reference to Darwin’s <em>Descent of Man</em> in <em>The Handmaid’s Tale</em> is not only relevant but even necessary.</p><img src="https://counter.theconversation.com/content/127664/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Hesketh holds an Australian Research Council Future Fellowship grant FT170100194, entitled "The Place of History in Science: Reassessing the Darwinian Revolution."</span></em></p>In the television show ‘The Handmaid’s Tale,’ Charles Darwin’s ‘Descent of Man’ makes a cameo — and its appearance makes a comment on how Gilead functions.Ian Hesketh, ARC Future Fellow, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.