tag:theconversation.com,2011:/us/topics/archaic-humans-53207/articlesArchaic humans – The Conversation2022-10-07T12:22:44Ztag:theconversation.com,2011:article/1919132022-10-07T12:22:44Z2022-10-07T12:22:44ZOur ‘Homo sapiens’ ancestors shared the world with Neanderthals, Denisovans and other types of humans whose DNA lives on in our genes<figure><img src="https://images.theconversation.com/files/488681/original/file-20221007-12-xnxe5b.jpg?ixlib=rb-1.1.0&rect=22%2C11%2C2320%2C1616&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hundreds of thousands of years ago, our *Homo sapiens* ancestors shared the landscape with multiple other hominins.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-exhibit-hall-includes-more-than-75-skulls-including-two-news-photo/129710842">The Washington Post via Getty Images</a></span></figcaption></figure><p>When the <a href="https://www.livescience.com/how-many-human-species.html">first modern humans arose</a> in East Africa sometime between 200,000 and 300,000 years ago, the world was very different compared to today. Perhaps the biggest difference was that we – meaning people of our species, <em>Homo sapiens</em> – were only one of several types of humans (or <a href="https://australian.museum/learn/science/human-evolution/hominid-and-hominin-whats-the-difference/">hominins</a>) that simultaneously existed on Earth.</p>
<p>From the well-known <a href="https://humanorigins.si.edu/evidence/genetics/ancient-dna-and-neanderthals">Neanderthals</a> and <a href="https://theconversation.com/fresh-clues-to-the-life-and-times-of-the-denisovans-a-little-known-ancient-group-of-humans-110504">more enigmatic Denisovans</a> in Eurasia, to the diminutive <a href="https://theconversation.com/the-hobbits-were-extinct-much-earlier-than-first-thought-56922">“hobbit” <em>Homo floresiensis</em></a> on the island of Flores in Indonesia, to <a href="https://theconversation.com/i-was-part-of-the-team-that-found-the-homo-naledi-childs-skull-how-we-did-it-171153"><em>Homo naledi</em> that lived in South Africa</a>, multiple hominins abounded.</p>
<p>Then, between 30,000 and 40,000 years ago, <a href="https://flexbooks.ck12.org/cbook/ck-12-college-human-biology-flexbook-2.0/section/7.6/primary/lesson/neanderthals-and-other-archaic-humans-chumbio/">all but one type of these hominins disappeared</a>, and for the first time we were alone.</p>
<p>Until recently, one of the mysteries about human history was whether our ancestors interacted and mated with these other types of humans before they went extinct. This fascinating question was the subject of great and often contentious <a href="https://www.sfgate.com/science/article/Neanderthal-love-Scientists-split-over-how-much-2626826.php">debates among scientists for decades</a>, because the data needed to answer this question simply didn’t exist. In fact, it seemed to many that the data would never exist.</p>
<p><a href="https://scholar.google.com/citations?user=_Urs-74AAAAJ&hl=en&oi=ao">Svante Pääbo</a>, however, paid little attention to what people thought was or was not possible. His persistence in developing tools to extract, sequence and interpret ancient DNA enabled sequencing the genomes of <a href="https://doi.org/10.1126/science.1188021">Neanderthals</a>, <a href="https://www.nature.com/articles/nature09710">Denisovans</a> and <a href="https://doi.org/10.1038/nature14558">early modern humans</a> who lived over 45,000 years ago.</p>
<p><a href="https://www.nobelprize.org/prizes/medicine/2022/press-release/">For developing this new field of paleogenomics</a>, Pääbo was awarded the 2022 Nobel Prize in Physiology or Medicine. This honor is not only well-deserved recognition for Pääbo’s triumphs, but also for evolutionary genomics and the insights it can contribute toward a more comprehensive understanding of human health and disease.</p>
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<a href="https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of human lineages diverging and interbreeding over time" src="https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=621&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=621&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=621&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=780&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=780&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488774/original/file-20221007-24-40vkma.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=780&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 simplified model of human evolution showing how humans are related to Neanderthals and Denisovans. Arrows between different branches show mating that occurred. Events that happened further back in time are closer to the top of the image.</span>
<span class="attribution"><span class="source">Joshua Akey</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>Mixing and mating, revealed by DNA</h2>
<p>Genetic studies of living people over the past several decades revealed the general contours of human history. Our species arose in Africa, dispersing out from that continent around 60,000 years ago, ultimately spreading to nearly all habitable places on Earth. Other types of humans existed as modern humans migrated throughout the world, but the genetic data showed little evidence that modern humans mated with other hominins.</p>
<p>Over the past decade, however, the study of ancient DNA, recovered from fossils up to around <a href="https://www.scientificamerican.com/article/oldest-ancient-human-dna-details-dawn-of-neandertals/">400,000 years old</a>, has revealed startling new twists and turns in the story of human history. </p>
<p>For example, the Neanderthal genome provided the data necessary to definitively show that humans and Neanderthals mated. Non-African people alive today inherited about <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5772775/">2% of their genomes</a> from Neanderthal ancestors, thanks to this kind of interbreeding.</p>
<p>In one of the biggest surprises, when Pääbo and his colleagues sequenced ancient DNA obtained from a small finger bone fragment that was assumed to be Neanderthal, it turned out to be an entirely <a href="https://doi.org/10.1038/nature09710">unknown type of human, now called Denisovans</a>. <a href="https://nautil.us/the-human-family-tree-it-turns-out-is-complicated-238239/">Humans and Denisovans also mated</a>, with the highest levels of Denisovan ancestry present today – between 4% and 6% – in individuals of Oceanic ancestry.</p>
<p>Strikingly, ancient DNA from a 90,000-year-old female revealed that she had <a href="https://doi.org/10.1038/d41586-018-06004-0">a Neanderthal mother and a Denisovan father</a>. Although there are still many unanswered questions, the picture emerging from analyses of ancient and modern DNA is that not only did multiple hominins overlap in time and space, but that matings were relatively common.</p>
<h2>Archaic genes you carry today</h2>
<p>Estimating the proportion of ancestry that modern individuals have from Neanderthals or Denisovans is certainly interesting. But ancestry proportions provide limited information about the consequences of these ancient matings.</p>
<p>For instance, does DNA inherited from Neanderthals and Denisovans influence biological functions that occur within our cells? Does this DNA influence traits like eye color or susceptibility to disease? Were DNA sequences from our evolutionary cousins ever beneficial, helping humans adapt to new environments?</p>
<p>To answer these questions, we need to identify the bits of Neanderthal and Denisovan DNA scattered throughout the genomes of modern individuals.</p>
<p>In 2014, <a href="https://akeylab.princeton.edu">my group</a> and <a href="https://reich.hms.harvard.edu">David Reich’s group</a> independently published the <a href="https://www.science.org/doi/10.1126/science.1245938">first maps of</a> <a href="https://www.nature.com/articles/nature12961">Neanderthal sequences</a> that survive in the DNA of modern humans. Today, roughly 40% of the Neanderthal genome has been recovered not by sequencing ancient DNA recovered from a fossil, but indirectly by <a href="https://doi.org/10.1016/j.cub.2022.08.027">piecing together the Neanderthal sequences</a> that persist in the genomes of contemporary individuals.</p>
<p>Similarly, in 2016 <a href="https://doi.org/10.1126/science.aad9416">my group</a> and <a href="https://doi.org/10.1016/j.cub.2016.03.037">David Reich’s group</a> published the first comprehensive catalogs of DNA sequences in modern individuals inherited from Denisovan ancestors. Surprisingly, when we analyzed the Denisovan sequences that persist in people today, we discovered they came from two distinct Denisovan populations, and therefore at least <a href="https://doi.org/10.1016/j.cell.2018.02.031">two separate waves of matings occurred between Denisovans and modern humans</a>. </p>
<p>The analysis of Neanderthal and Denisovan DNA in modern humans reveals that some of their sequence was harmful and rapidly got purged from human genomes. In fact, the initial fraction of Neanderthal ancestry in humans who lived approximately 45,000 years ago was around 10%. That amount rapidly declined over a small number of generations to the 2% <a href="https://doi.org/10.1073/pnas.1814338116">observed in contemporary individuals</a>.</p>
<p>The removal of deleterious archaic sequences also created large regions of the human genome that are significantly depleted of both Neanderthal and Denisovan ancestry. These deserts of archaic hominin sequences are interesting because they may help identify genetic changes that contribute to <a href="https://www.ncbi.nlm.nih.gov/books/NBK210023/">uniquely modern human traits</a>, such as our capacity for language, symbolic thought and culture, although there is debate about just <a href="https://doi.org/10.1098/rstb.2019.0424">how unique these traits are to modern humans</a>. </p>
<p>In contrast, there are also sequences inherited from Neanderthals and Denisovans that were advantageous, and helped modern humans adapt to new environments as they dispersed out of Africa. Neanderthal versions of several immune-related genes have risen to high frequency in several non-African populations, which likely <a href="https://www.quantamagazine.org/how-neanderthal-dna-helps-humanity-20160526/">helped humans fend off exposure to new pathogens</a>. Similarly, a version of the <em>EPAS1</em> gene, which contributes to <a href="https://www.nationalgeographic.com/science/article/sex-with-extinct-humans-passed-high-altitude-gene-to-tibetans">high-altitude adaptation</a> in Tibetan populations, was inherited from Denisovans.</p>
<p>It is also becoming clear that DNA sequences inherited from Neanderthal and Denisovan ancestors contribute to the burden of disease in present day individuals. Neanderthal sequences have been shown to <a href="https://doi.org/10.1038/s41586-020-2818-3">influence both susceptibility to</a> and <a href="https://doi.org/10.1073/pnas.2026309118">protection against severe COVID-19</a>. Archaic hominin sequences have also <a href="https://doi.org/10.1016/j.cub.2022.08.027">been shown to influence</a> susceptibility to depression, Type 2 diabetes and celiac disease among others. Ongoing studies will undoubtedly reveal more about how Neanderthal and Denisovan ancestry contributes to human disease.</p>
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<a href="https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="photo of man holding a human skull and looking at the face" src="https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488685/original/file-20221007-17489-agxzvz.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">Svante Pääbo’s work built the foundation of the new field of paleogenomics.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/svante-paabo-director-of-the-max-planck-institute-for-news-photo/1243699506">Jens Schluete via Getty Images News</a></span>
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<p>I was a graduate student when the <a href="https://www.genome.gov/11006929/2003-release-international-consortium-completes-hgp">Human Genome Project</a> was nearing completion a little over two decades ago. I was drawn to genetics because I found it fascinating that, by analyzing the DNA of present-day individuals, you could learn aspects about a population’s history that occurred tens of thousands of years ago.</p>
<p>Today, I am just as fascinated by the stories contained in our DNA, and the work of Svante Pääbo and his colleagues has enabled these stories to be told in a way that simply was not possible before.</p><img src="https://counter.theconversation.com/content/191913/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joshua Akey receives funding from NIH. </span></em></p>Ancient DNA helps reveal the tangled branches of the human family tree. Not only did our ancestors live alongside other human species, they mated with them, too.Joshua Akey, Professor at the Lewis-Sigler Institute for Integrative Genomics, Princeton UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1630842021-06-24T20:13:53Z2021-06-24T20:13:53Z‘Homo’ who? A new mystery human species has been discovered in Israel<figure><img src="https://images.theconversation.com/files/407818/original/file-20210623-15-156gf8w.jpeg?ixlib=rb-1.1.0&rect=10%2C20%2C3488%2C2308&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Yossi Zaidner</span></span></figcaption></figure><p>An international group of archaeologists have discovered a missing piece in the story of human evolution.</p>
<p>Excavations at the Israeli site of Nesher Ramla have recovered a skull that may represent a late-surviving example of a distinct <em>Homo</em> population, which lived in and around modern-day Israel from about 420,000 to 120,000 years ago. </p>
<p>As researchers Israel Hershkovitz, Yossi Zaidner and colleagues detail in two companion studies <a href="https://science.sciencemag.org/cgi/doi/10.1126/science.abh3169">published</a> <a href="https://science.sciencemag.org/cgi/doi/10.1126/science.abj3077">today</a> in Science, this archaic human community traded both their culture and genes with nearby <em>Homo sapiens</em> groups for many thousands of years.</p>
<h2>The new fossils</h2>
<p>Pieces of a skull, including a right parietal (towards the back/side of the skull) and an almost complete mandible (jaw) were dated to 140,000–120,000 years old, with analysis finding the person it belonged to wasn’t fully <em>H. sapiens</em>. </p>
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<a href="https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=313&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=313&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=313&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=394&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=394&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407817/original/file-20210623-27-pq5orw.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=394&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 Nesher Ramla mandible and skull.</span>
<span class="attribution"><span class="source">Avi Levin and Ilan Theiler, Sackler / Tel Aviv University</span></span>
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</figure>
<p>Nor were they Neanderthal, however, which was the only other type of human thought to have been living in the region at the time.</p>
<p>Instead, this individual falls right smack in the middle: a unique population of <em>Homo</em> never before recognised by science.</p>
<p>Through detailed comparison with many other fossil human skulls, the researchers found the parietal bone featured “archaic” traits that are substantially different from both early and recent <em>H. sapiens</em>. In addition, the bone is considerably thicker than those found in both Neanderthals and most early <em>H. sapiens</em>.</p>
<p>The jaw too displays archaic features, but also includes forms commonly seen in Neanderthals.</p>
<p>The bones together reveal a unique combination of archaic and Neanderthal features, distinct from both early <em>H. sapiens</em> and later Neanderthals.</p>
<h2>Are there are more of these people?</h2>
<p>The authors suggest fossils found at other Israeli sites, including the famous <a href="https://humanorigins.si.edu/evidence/human-fossils/fossils/tabun-1">Lady of Tabun</a>, might also be part of this new human population, in contrast to their previous Neanderthal or <em>H. sapiens</em> identification. </p>
<p>The “Lady of Tabun” (known to archaeologists as Tabun C1) was discovered in 1932 by pioneering archaeologist <a href="https://trowelblazers.com/yusra-expert-excavator-of-mount-carmel/">Yusra</a> and her field director, Dorothy Garrod.</p>
<p>Extensively studied, this important specimen taught us much about Neanderthal anatomy and behaviour in a time when very little was known about our enigmatic evolutionary cousins. </p>
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Read more:
<a href="https://theconversation.com/ancient-teenager-the-first-known-person-with-parents-of-two-different-species-101965">Ancient teenager the first known person with parents of two different species</a>
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<p>If Tabun C1 and others from the Qesem and Zuttiyeh Caves were indeed members of the Nasher Ramel <em>Homo</em> group, this reanalysis would explain some inconsistencies in their anatomy previously noted by researchers.</p>
<p>The mysterious Nesher Ramla <em>Homo</em> may even represent our most recent common ancestor with Neanderthals. Its mix of traits supports genetic evidence that early <a href="https://www.nature.com/articles/ncomms16046">gene flow between <em>H. sapiens</em> and Neanderthals</a> occurred between 400,000 and 200,000 years ago. In other words, that interbreeding between the different <em>Homo</em> populations was more common than previously thought.</p>
<p>Even more puzzling, the team also found a collection of some 6,000 stone tools at the Nesher Ramla site. </p>
<p>These tools were made the same way contemporaneous <em>H. sapiens</em> groups made their technology, with the similarity so strong it appears the two populations — Nesher Ramla <em>Homo</em> and <em>H. sapiens</em> — were hanging out on a regular basis. It seems they weren’t just exchanging genes, but also tips on tool-making. </p>
<h2>And there was fire!</h2>
<p>The site also produced bones of animals caught, butchered, and eaten on-site. These findings indicate Nesher Ramla <em>Homo</em> hunted a range of species, including tortoise, gazelle, aurochs, boar and ostrich. </p>
<p>Furthermore, they were using <a href="https://www.youtube.com/watch?v=Wpfwu__PF7Y&t=9s">fire to cook their meals</a>, evident through the uncovering of a campfire feature the same age as the fossils. Indeed, the Nesher Ramla <em>Homo</em> were not only collecting wood to make campfires and cook, but were also actively managing their fires as people do today. </p>
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<a href="https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407814/original/file-20210623-27-1aabcll.jpeg?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>
<figcaption>
<span class="caption">Exposure of animal bones and lithic artifacts in the layer with the Nesher Ramla Homo fossils.</span>
<span class="attribution"><span class="source">Yossi Zaidner</span></span>
</figcaption>
</figure>
<p>While the earliest indications of controlled use of fire is much older — perhaps one million years ago - the interesting thing about this particular campfire is the evidence that Nesher Ramla people tended to it as carefully as contemporary <em>H. sapiens</em> and Neanderthals did their own fires.</p>
<p>Most impressive is that the campfire feature survived, intact, outside of a protected cave environment for so long. It is now the oldest intact campfire ever found in the open air.</p>
<p>In sum, if we think of the story of human evolution like an Ikea bookcase that isn’t quite coming together, this discovery is effectively like finding the missing shelf buried at the bottom of the box. The new Nesher Ramla <em>Homo</em> allows for a better-fitting structure, although a few mysterious “extra” pieces remain to be pondered over. </p>
<p>For example, exactly how did the different <em>Homo</em> groups interact with each other? And what does it mean for the cultural and biological changes that were occurring for <em>Homo</em> populations in this period? </p>
<p>Continuing to work with these questions (the “extra pieces”) will help us build a better understanding of our human past.</p>
<img src="https://counter.theconversation.com/content/163084/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Michelle Langley is a Senior Research Fellow in the Australian Research Centre for Human Evolution and Lecturer in Archaeology in the School of Environment and Science at Griffith University. She receives funding from the Australian Research Council. </span></em></p>The 140,000-year-old skull fossils are leading to more questions than answers. Also found was the oldest intact campfire ever found in the open air.Michelle Langley, Senior Research Fellow, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1615852021-06-23T20:04:12Z2021-06-23T20:04:12ZDirty secrets: sediment DNA reveals a 300,000-year timeline of ancient and modern humans living in Siberia<figure><img src="https://images.theconversation.com/files/407374/original/file-20210621-35447-1spt3ea.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Collection of sediment DNA samples in the Main Chamber of Denisova Cave.</span> <span class="attribution"><span class="source">Bert Roberts</span>, <span class="license">Author provided</span></span></figcaption></figure><p>In the foothills of the Altai Mountains in southern Siberia lies Denisova Cave. It is the only site in the world known to have been inhabited by the eponymous Denisovans and their close relatives the Neanderthals (<em>Homo neanderthalensis</em>) — which <a href="https://www.nature.com/articles/d41586-018-06004-0">overlapped at times</a> — as well as by some of the earliest modern humans (<em>Homo sapiens</em>) to have dispersed into northern Asia.</p>
<p>Our <a href="https://www.nature.com/articles/s41586-021-03675-0">new study</a> pieces together the history of this site over the past 300,000 years from fragments of ancient DNA that survived in the cave sediments. Our findings reveal multiple turnovers of archaic and modern humans during this period, as well as major changes in the diversity of other animals.</p>
<p>We discovered Denisovans were the earliest toolmakers at the site, while Neanderthals were the sole human occupants between about 130,000 and 80,000 years ago. The first modern humans arrived much later, just as the last Denisovans and Neanderthals were leaving the scene.</p>
<p>We also detected marked changes in the types of human and animal DNA around 200,000 and 100,000 years ago, coincident with major shifts in climate and environmental conditions.</p>
<h2>Genetic ghosts</h2>
<p>Excavations in the cave by our Russian colleagues have unearthed about a dozen fossils of Denisovans and Neanderthals over the past 40 years, but none of modern humans. </p>
<p>Rather, the presence of modern humans at the cave has been surmised based on the recovery of artefacts made from stone, animal bones and teeth, mammoth ivory, ostrich eggshells, marble and gemstones.</p>
<p>The rarity of fossils at the site has also meant that questions persist about when different groups of humans occupied the cave, and which of them was responsible for making specific artefacts.</p>
<p>We managed to put flesh on the missing bones by using genetic traces of ancient humans and various other mammals preserved in the cave sediments. And we did so without having to find more fossils.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/403446/original/file-20210530-23-xbvsni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/403446/original/file-20210530-23-xbvsni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403446/original/file-20210530-23-xbvsni.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403446/original/file-20210530-23-xbvsni.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403446/original/file-20210530-23-xbvsni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403446/original/file-20210530-23-xbvsni.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403446/original/file-20210530-23-xbvsni.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Project leader, Matthias Meyer, in the ancient DNA clean lab at the Max Planck Institute for Evolutionary Anthropology.</span>
<span class="attribution"><span class="source">Max Planck Institute for Evolutionary Anthropology</span></span>
</figcaption>
</figure>
<p>Our latest work is the most comprehensive study yet of ancient DNA extracted from sediment at any single site in the world. It builds on our <a href="https://science.sciencemag.org/content/356/6338/605">trailblazing research</a> published in 2017.</p>
<p>We extracted mitochondrial DNA from more than 700 samples and anchored them to a <a href="https://www.nature.com/articles/s41586-018-0843-2">timeline</a> for Denisova Cave, generating a detailed picture of which humans and animals were present at this famous site at various times in the past.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fresh-clues-to-the-life-and-times-of-the-denisovans-a-little-known-ancient-group-of-humans-110504">Fresh clues to the life and times of the Denisovans, a little-known ancient group of humans</a>
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</p>
<hr>
<h2>Turbulent times</h2>
<p>We retrieved ancient human DNA from 175 sediment samples — more than ten times the number of human fossils found at the site. Several interesting findings emerged from our genetic analyses.</p>
<p>We found Denisovans were present at the cave, on and off, from 250,000 years ago until 60,000 years ago. And they were the only humans at the site between 250,000 and 200,000 years ago, so we can now say with more confidence they likely produced the stone tools recovered from these layers. </p>
<p>Denisovan fossils and ancient DNA have been found at only one <a href="https://theconversation.com/how-midnight-digs-at-a-holy-tibetan-cave-opened-a-window-to-prehistoric-humans-living-on-the-roof-of-the-world-148927">other site</a>, on the edge of the Tibetan Plateau.</p>
<p>Meanwhile, Neanderthals first appeared at Denisova Cave about 200,000 years ago, with a variety of DNA that was previously unknown. They vanished from the site about 40,000 years ago, around the same time Neanderthals disappeared in other parts of Eurasia.</p>
<p>Importantly, we could only find traces of Neanderthal DNA in sediments dated to between 130,000 and 80,000 years ago at Denisova Cave — and none of Denisovans.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/404606/original/file-20210605-27-1ye28kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/404606/original/file-20210605-27-1ye28kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=699&fit=crop&dpr=1 600w, https://images.theconversation.com/files/404606/original/file-20210605-27-1ye28kn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=699&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/404606/original/file-20210605-27-1ye28kn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=699&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/404606/original/file-20210605-27-1ye28kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=878&fit=crop&dpr=1 754w, https://images.theconversation.com/files/404606/original/file-20210605-27-1ye28kn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=878&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/404606/original/file-20210605-27-1ye28kn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=878&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Summary timeline of the different types of human, bear and hyaena DNA in sediments at Denisova Cave. White gaps indicate missing parts of the sedimentary sequence. The graph on the left shows the changes in climate between relatively cold and warm conditions recorded in drill cores from Lake Baikal, also in southern Siberia.</span>
<span class="attribution"><span class="source">Bert Roberts</span></span>
</figcaption>
</figure>
<p>This time interval coincides with a major change in Earth’s climate: the start of the last interglacial. This was a relatively warm period similar to the present. It marked a switch from one type of Denisovan DNA before 130,000 years ago to another after 80,000 years ago.</p>
<p>This matches previous findings from genetic analysis of Denisovan fossils, which indicated a possible turnover in Denisovan populations. It also coincides with a population replacement of <a href="https://science.sciencemag.org/content/372/6542/eabf1667.full">Neanderthals in Spain</a> about 100,000 years ago — again identified from ancient DNA in cave sediments.</p>
<p>We also recovered the ancient DNA of modern humans from sediments deposited at Denisova Cave within the last 60,000 years. No modern human fossils have been found at the site, so these traces of DNA — from the same layers as the jewellery and pendants made from stone, bone, tooth and ivory — are the first direct evidence of <em>Homo sapiens</em>’ presence at the cave.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/403456/original/file-20210530-15-1thvbk4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/403456/original/file-20210530-15-1thvbk4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=346&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403456/original/file-20210530-15-1thvbk4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=346&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403456/original/file-20210530-15-1thvbk4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=346&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403456/original/file-20210530-15-1thvbk4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403456/original/file-20210530-15-1thvbk4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403456/original/file-20210530-15-1thvbk4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=435&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Selection of stone tools and personal ornaments made from bone, tooth and ivory recovered from the same sediment layers as modern human ancient DNA.</span>
<span class="attribution"><span class="source">Institute of Archaeology and Ethnography of the Siberian Branch of the Russian Academy of Sciences.</span></span>
</figcaption>
</figure>
<h2>Denisova zoo</h2>
<p>We recovered other ancient animal DNA from 94% of the sediment samples. This is providing new vistas into cave use by more than 12 taxonomic families of mammals, including species such as bear, hyena, wolf and woolly mammoth.</p>
<p><a href="https://www.nature.com/articles/s41598-019-49930-3">Previous studies</a> have shown the cave was occupied at times by hyenas and bears. Our findings take this further, revealing cave bears dominated between 300,000 and 200,000 years ago, after which brown bears became more abundant.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/dishing-the-dirt-sediments-reveal-a-famous-early-human-cave-site-was-also-home-to-hyenas-and-wolves-122458">Dishing the dirt: sediments reveal a famous early human cave site was also home to hyenas and wolves</a>
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</p>
<hr>
<p>We also identified two major shifts in the types of hyena present at different times, with turnovers occurring when climatic conditions changed from relatively warm to cold 200,000 years ago, and from relatively cold to warm 100,000 years ago.</p>
<p>The timing of these turnovers, coupled with the patterns we discovered for Denisovans and Neanderthals, suggests these events were likely connected to environmental changes.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/aqdu2vjuCUY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A guided tour of our key findings, presented by the lead author of the study, Elena Zavala from the Max Planck Institute for Evolutionary Anthropology.</span></figcaption>
</figure>
<h2>Sediment diaries</h2>
<p>The power of sediment DNA lies in the fact that sediments are ubiquitous at archaeological and palaeontological sites. Even tiny samples can contain genetic traces of a variety of animals — including humans — in the absence of fossils.</p>
<p>Sediments also often contain plant remains and other materials that can be used to reconstruct ancient environments, with timelines obtained by <a href="https://www.nature.com/articles/520438a">directly dating</a> sediment grains.</p>
<p>By sampling sites with high densities of sediment DNA, the ebb and flow of humans and other animals can be compared to records of past environmental change. Making these crucial connections can help illuminate the dark corners of our planet’s history.</p><img src="https://counter.theconversation.com/content/161585/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elena Zavala receives funding from the Max Planck Society. </span></em></p><p class="fine-print"><em><span>Matthias Meyer receives funding from the Max Planck Society. </span></em></p><p class="fine-print"><em><span>Richard 'Bert' Roberts receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Zenobia Jacobs receives funding from the Australian Research Council. </span></em></p>Our research has also uncovered major long-term changes in ancient animal populations at Denisova Cave, and has provided the first direct evidence of Homo sapiens having lived there.Elena Zavala, PhD Student, Max Planck Institute for Evolutionary AnthropologyMatthias Meyer, Group Leader, Advanced DNA Sequencing Techniques Group, Max Planck Institute for Evolutionary AnthropologyRichard 'Bert' Roberts, Director, ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH), University of WollongongZenobia Jacobs, Professor, University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1266382019-11-21T15:33:10Z2019-11-21T15:33:10ZWere other humans the first victims of the sixth mass extinction?<figure><img src="https://images.theconversation.com/files/302005/original/file-20191115-66945-1ccxz9v.jpg?ixlib=rb-1.1.0&rect=5%2C291%2C830%2C485&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A Neanderthal skull shows head trauma, evidence of ancient violence</span> <span class="attribution"><a class="source" href="http://humanorigins.si.edu/evidence/human-fossils/fossils/saint-c%C3%A9saire">Smithsonian National Museum of Natural History</a></span></figcaption></figure><p>Nine human species walked the Earth 300,000 years ago. Now there is just one. The Neanderthals, <em>Homo neanderthalensis</em>, were <a href="https://theconversation.com/why-the-neanderthals-may-have-been-more-sophisticated-hunters-than-we-thought-new-study-98870">stocky hunters</a> adapted to Europe’s cold steppes. The related <a href="https://theconversation.com/fresh-clues-to-the-life-and-times-of-the-denisovans-a-little-known-ancient-group-of-humans-110504">Denisovans</a> inhabited Asia, while the more primitive <a href="https://theconversation.com/a-snapshot-of-our-mysterious-ancestor-homo-erectus-101122"><em>Homo erectus</em></a> lived in Indonesia, and <a href="https://www.nature.com/articles/108371a0.pdf"><em>Homo rhodesiensis</em></a> in central Africa. </p>
<p>Several short, small-brained species survived alongside them: <a href="https://theconversation.com/homo-naledi-fossil-discovery-a-triumph-for-open-access-and-education-47726"><em>Homo naledi</em></a> in South Africa, <a href="https://theconversation.com/how-much-evidence-is-enough-to-declare-a-new-species-of-human-from-a-philippines-cave-site-115139"><em>Homo luzonensis</em></a> in the Philippines, <a href="https://theconversation.com/fast-evolution-explains-the-tiny-stature-of-extinct-hobbit-from-flores-island-124747"><em>Homo floresiensis</em></a> (“hobbits”) in Indonesia, and the mysterious <a href="https://theconversation.com/bone-suggests-red-deer-cave-people-a-mysterious-species-of-human-52437">Red Deer Cave People</a> in China. Given how quickly we’re discovering new species, more are likely waiting to be found.</p>
<p>By 10,000 years ago, they were all gone. The disappearance of these other species resembles a mass extinction. But there’s no obvious environmental catastrophe – volcanic eruptions, climate change, asteroid impact – driving it. Instead, the extinctions’ timing suggests they were caused by the spread of a new species, evolving <a href="https://science.sciencemag.org/content/358/6363/652.abstract">260,000-350,000 years ago</a> in <a href="https://www.nature.com/articles/s41586-019-1714-1">Southern Africa</a>: <em>Homo sapiens</em>. </p>
<p>The spread of modern humans out of Africa has caused a <a href="https://www.theguardian.com/environment/2017/jul/10/earths-sixth-mass-extinction-event-already-underway-scientists-warn">sixth mass extinction</a>, a greater than 40,000-year event extending from the disappearance of Ice Age mammals to the destruction of rainforests by civilisation today. But were other humans the first casualties? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/302000/original/file-20191115-66925-p0qco1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Human evolution.</span>
<span class="attribution"><span class="source">Nick Longrich</span></span>
</figcaption>
</figure>
<p>We are a uniquely dangerous species. We hunted <a href="https://www.amazon.com/Quaternary-Extinctions-Prehistoric-Paul-Martin/dp/0816511004/ref=sr_1_3?keywords=prehistoric+extinctions+martin&qid=1573645985&sr=8-3">wooly mammoths, ground sloths</a> and <a href="https://science.sciencemag.org/content/287/5461/2250.full?_ga=2.156387641.382776719.1573642705-28080894.1573476299">moas</a> to extinction. We destroyed plains and forests for farming, modifying over <a href="https://www.geosociety.org/gsatoday/archive/22/12/article/i1052-5173-22-12-4.htm">half the planet’s land area</a>. We altered the planet’s climate. But we are most dangerous to other human populations, because we compete for resources and land.</p>
<p>History is full of examples of people warring, displacing and wiping out other groups over territory, from Rome’s destruction of Carthage, to the American conquest of the West and the British colonisation of Australia. There have also been recent genocides and ethnic cleansing in <a href="https://theconversation.com/remembering-srebrenica-more-than-20-years-on-99122">Bosnia</a>, Rwanda, <a href="https://theconversation.com/islamic-states-genocidal-crimes-demand-justice-how-can-it-be-done-97646">Iraq</a>, Darfur and <a href="https://theconversation.com/rohingya-crisis-this-is-what-genocide-looks-like-83924">Myanmar</a>. Like language or tool use, a capacity for and tendency to engage in genocide is arguably an intrinsic, <a href="https://www.amazon.com/Third-Chimpanzee-Evolution-Future-Animal/dp/0060845503/ref=sr_1_1?keywords=the+third+chimpanzee&qid=1573645399&sr=8-1">instinctive part of human nature</a>. There’s little reason to think that early <em>Homo sapiens</em> were less territorial, less violent, less intolerant – less human.</p>
<p>Optimists have painted early hunter-gatherers as peaceful, <a href="https://theconversation.com/explainer-the-myth-of-the-noble-savage-55316">noble savages</a>, and have argued that our culture, not our nature, creates violence. But field studies, historical accounts, and archaeology <a href="https://www.amazon.com/Constant-Battles-Why-We-Fight/dp/0312310900/ref=sr_1_1?keywords=constant+battles&qid=1573829278&sr=8-1">all show</a> that war in <a href="https://www.amazon.com/War-Before-Civilization-Peaceful-Savage/dp/0195119126">primitive cultures was intense, pervasive and lethal</a>. Neolithic weapons such as clubs, spears, axes and bows, combined with guerrilla tactics like raids and ambushes, were devastatingly effective. Violence was the leading cause of death among men in these societies, and wars saw higher casualty levels per person than World Wars I and II. </p>
<p>Old bones and artefacts show this violence is ancient. The 9,000-year-old Kennewick Man, from North America, has a spear point embedded in his pelvis. The 10,000-year-old <a href="https://www.nature.com/articles/nature16477">Nataruk site</a> in Kenya documents the brutal massacre of at least 27 men, women, and children. </p>
<p>It’s unlikely that the other human species were much more peaceful. The existence of <a href="https://www.nature.com/articles/nature13727">cooperative violence in male chimps</a> suggests that war predates the evolution of humans. Neanderthal skeletons show <a href="https://www.nature.com/articles/s41586-018-0696-8">patterns</a> of <a href="https://www.pnas.org/content/99/9/6444.short">trauma</a> consistent with warfare. But sophisticated weapons likely gave <em>Homo sapiens</em> a military <a href="http://www.paleoanthro.org/media/journal/content/PA20100100.pdf">advantage</a>. The arsenal of early <em>Homo sapiens</em> probably included <a href="https://www.sciencedirect.com/science/article/pii/S030544030500230X">projectile weapons</a> like javelins and <a href="http://digitallibrary.amnh.org/bitstream/handle/2246/2613/N2403.pdf?sequence=1">spear-throwers</a>, throwing sticks and <a href="https://www.nature.com/articles/nature16477">clubs</a>.</p>
<p>Complex tools and culture would also have helped us efficiently harvest a wider range of animals and plants, feeding larger tribes, and giving our species a strategic advantage in numbers.</p>
<h2>The ultimate weapon</h2>
<p>But cave <a href="https://theconversation.com/borneo-cave-discovery-is-the-worlds-oldest-rock-art-in-southeast-asia-106252?fbclid=IwAR38kVzZ5Pa1zSZH7ZGWz1jFwJBRt_m035lvW-H6coqc8evaHWD1Ba6HisI">paintings</a>, <a href="https://www.nature.com/articles/nature07995">carvings</a>, and <a href="https://www.nature.com/articles/nature08169">musical instruments</a> hint at something far more dangerous: a sophisticated capacity for abstract thought and communication. The ability to cooperate, plan, <a href="https://www.amazon.com/War-Carl-von-Clausewitz-ebook/dp/B005R9EB68/ref=sr_1_1?keywords=clausewitz+on+war&qid=1573644303&s=digital-text&sr=1-1">strategise</a>, <a href="http://www.gutenberg.org/ebooks/1232">manipulate</a> and <a href="https://www.amazon.com/Art-War-Sun-Tzu-ebook/dp/B07YRX3MBM/ref=sr_1_2?keywords=sun+tzu+giles&qid=1573644250&s=digital-text&sr=1-2">deceive</a> may have been our ultimate weapon.</p>
<p>The incompleteness of the fossil record makes it hard to test these ideas. But in Europe, the only place with a relatively complete archaeological record, fossils show that within <a href="https://www.nature.com/articles/nature13621">a few thousand years</a> of our arrival , Neanderthals vanished. Traces of <a href="https://science.sciencemag.org/content/328/5979/710/tab-pdf">Neanderthal DNA in some Eurasian people</a> prove we didn’t just replace them after they went extinct. We met, and we mated.</p>
<p>Elsewhere, DNA tells of other encounters with archaic humans. East Asian, Polynesian and Australian groups have <a href="https://www.nature.com/articles/nature09710">DNA</a> from <a href="https://www.cell.com/cell/fulltext/S0092-8674(19)30218-1">Denisovans</a>. DNA from <a href="https://www.nature.com/articles/ng.3621#ref23">another species</a>, possibly <em>Homo erectus</em>, occurs in many Asian people. African genomes <a href="https://www.pnas.org/content/108/37/15123">show traces of DNA</a> from yet another <a href="https://www.sciencedirect.com/science/article/pii/S0092867412008318">archaic species</a>. The fact that we interbred with these other species proves that they disappeared only after encountering us. </p>
<p>But why would our ancestors wipe out their relatives, causing a mass extinction – or, perhaps more accurately, a mass genocide?</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/301300/original/file-20191112-178506-5fhhk2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/301300/original/file-20191112-178506-5fhhk2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=639&fit=crop&dpr=1 600w, https://images.theconversation.com/files/301300/original/file-20191112-178506-5fhhk2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=639&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/301300/original/file-20191112-178506-5fhhk2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=639&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/301300/original/file-20191112-178506-5fhhk2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=803&fit=crop&dpr=1 754w, https://images.theconversation.com/files/301300/original/file-20191112-178506-5fhhk2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=803&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/301300/original/file-20191112-178506-5fhhk2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=803&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">13,000-year-old spear points from Colorado.</span>
<span class="attribution"><span class="source">Chip Clark, Smithsonian Institution</span></span>
</figcaption>
</figure>
<p>The answer lies in <a href="https://www.amazon.com/Constant-Battles-Why-We-Fight/dp/0312310900/ref=sr_1_1?keywords=constant+battles&qid=1573829278&sr=8-1">population growth</a>. Humans reproduce exponentially, like all species. Unchecked, we historically <a href="http://www.gutenberg.org/ebooks/4239">doubled our numbers every 25 years</a>. And once humans became cooperative hunters, we had no predators. Without predation controlling our numbers, and little family planning beyond <a href="http://www.gutenberg.org/ebooks/4239">delayed marriage</a> and <a href="https://www.annualreviews.org/doi/pdf/10.1146/annurev.es.06.110175.000543">infanticide</a>, populations grew to exploit the available resources.</p>
<p>Further growth, or food shortages caused by drought, harsh winters or overharvesting resources <a href="https://www.amazon.com/Constant-Battles-Why-We-Fight/dp/0312310900/ref=sr_1_1?keywords=constant+battles&qid=1573829278&sr=8-1">would inevitably lead tribes into conflict</a> over food and foraging territory. Warfare became a check on population growth, perhaps the most important one.</p>
<p>Our elimination of other species probably wasn’t a planned, coordinated effort of the sort practised by civilisations, but a war of attrition. The end result, however, was just as final. Raid by raid, ambush by ambush, valley by valley, modern humans would have worn down their enemies and taken their land. </p>
<p>Yet the extinction of Neanderthals, at least, took a long time – thousands of years. This was partly because early <em>Homo sapiens</em> lacked the advantages of later conquering civilisations: <a href="https://www.amazon.com/Third-Chimpanzee-Evolution-Future-Animal/dp/0060845503/ref=sr_1_1?keywords=the+third+chimpanzee&qid=1573645399&sr=8-1">large numbers, supported by farming</a>, and <a href="https://www.amazon.com/Plagues-Peoples-William-McNeill-ebook/dp/B0047747QK/ref=sr_1_1?keywords=plagues+and+peoples&qid=1573645434&sr=8-1">epidemic diseases like smallpox, flu, and measles</a> that <a href="https://theconversation.com/european-colonisation-of-the-americas-killed-10-of-world-population-and-caused-global-cooling-110549">devastated their opponents</a>. But while Neanderthals lost the war, to hold on so long they must have fought and won many battles against us, suggesting a level of intelligence close to our own.</p>
<p>Today we look up at the stars and wonder if we’re <a href="https://theconversation.com/evolution-tells-us-we-might-be-the-only-intelligent-life-in-the-universe-124706">alone in the universe</a>. In <a href="https://www.amazon.com/Hobbit-Lord-Rings-Fellowship-Towers/dp/0345538374/ref=sr_1_2?keywords=the+lord+of+the+rings&qid=1573645527&sr=8-2">fantasy</a> and <a href="https://www.imdb.com/title/tt0060028/">science fiction</a>, we wonder what it might be like to meet other intelligent species, like us, but not us. It’s profoundly sad to think that we once did, and now, because of it, they’re gone.</p><img src="https://counter.theconversation.com/content/126638/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicholas R. Longrich 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>300,000 years ago, there were lots of different species of human. Now it’s only us – and we’re probably the reason why.Nicholas R. Longrich, Senior Lecturer, Paleontology and Evolutionary Biology, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/958792018-05-02T20:23:30Z2018-05-02T20:23:30ZRhino fossil rewrites the earliest human history of the Philippines<figure><img src="https://images.theconversation.com/files/216997/original/file-20180501-135851-a9qsa0.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Excavations at Kalinga in Luzon's Cagayan Valley (Philippines). </span> <span class="attribution"><span class="source">G.D. van den Bergh</span>, <span class="license">Author provided</span></span></figcaption></figure><p>A dig in Luzon, an island in the northern Philippines, has uncovered fossils of an “Ice Age” rhinoceros that was butchered around 700,000 years ago. It’s the first evidence demonstrating the presence of archaic humans in the Philippines.</p>
<p>This exciting new finding, published today in <a href="https://www.nature.com/articles/doi:10.1038/s41586-018-0072-8">Nature</a>, suggests that early hominins were more widespread than previously thought in <a href="https://theconversation.com/wallacea-a-living-laboratory-of-evolution-85602">Wallacea</a> – the vast network of islands located east of continental Eurasia.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/217001/original/file-20180501-135803-j4f8ud.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/217001/original/file-20180501-135803-j4f8ud.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/217001/original/file-20180501-135803-j4f8ud.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/217001/original/file-20180501-135803-j4f8ud.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/217001/original/file-20180501-135803-j4f8ud.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/217001/original/file-20180501-135803-j4f8ud.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/217001/original/file-20180501-135803-j4f8ud.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">The near-complete skeleton of an extinct rhino from Kalinga in Luzon.</span>
<span class="attribution"><span class="source">G.D. van den Bergh</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The work is published by an international research team, including French, Filipino, Australian and Dutch scientists. </p>
<p>They discovered the now-extinct rhino carcass during excavations at Kalinga in Luzon’s Cagayan Valley. Marks on the bones indicate slicing with sharp-edged stone tools, showing that hominins removed flesh and fat from this large animal which they either killed or found recently deceased. Simple stone tools were found near the rhino.</p>
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<em>
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Read more:
<a href="https://theconversation.com/ancient-stone-tools-found-on-sulawesi-but-who-made-them-remains-a-mystery-92277">Ancient stone tools found on Sulawesi, but who made them remains a mystery</a>
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<p>The rhino and tools were buried in river sediments. The team, co-led by <a href="https://cas.uow.edu.au/members/UOW094227.html">Gerrit (“Gert”) van den Bergh</a> from the University of Wollongong, has proposed an age of between 777,000 to 631,000 years ago for their discovery. We can be confident in these results because they used several independent dating methods that are all in agreement. </p>
<h2>Who butchered the rhino?</h2>
<p>In archaeological sciences, the term “archaic hominin” is generally used to refer to extinct forms of humans. </p>
<p>Prior research shows that archaic hominins had reached the islands of <a href="http://www.abc.net.au/news/science/2016-01-14/stone-tools-date-earliest-occupations-of-humans-on-sulawesi/7086308">Sulawesi</a> and <a href="http://www.sciencemag.org/news/2010/03/hobbit-ancestors-arrived-flores-early">Flores</a> to the south of Luzon by at least 200,000 years ago and one million years ago, respectively. Like Luzon, Sulawesi and Flores are large Wallacean islands located relatively close to the edge of the southeastern tip of continental Asia (“Sundaland”). </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216998/original/file-20180501-135848-1t7vdj0.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216998/original/file-20180501-135848-1t7vdj0.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216998/original/file-20180501-135848-1t7vdj0.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216998/original/file-20180501-135848-1t7vdj0.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216998/original/file-20180501-135848-1t7vdj0.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216998/original/file-20180501-135848-1t7vdj0.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216998/original/file-20180501-135848-1t7vdj0.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">The research team in Cagayan Valley, Luzon, Phillipines.</span>
<span class="attribution"><span class="source">G.D. van den Bergh</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Given that archaic hominins were able to colonise Sulawesi and Flores, it stands to reason that they also could have made it to the Philippines – but until now conclusive evidence for this has been lacking. </p>
<p>At this stage we don’t know which species the early tool-makers in Luzon belonged to, owing to the lack of hominin fossils from the rhino site.</p>
<p>However, the most likely candidate is <a href="https://australianmuseum.net.au/homo-erectus"><em>Homo erectus</em></a>, a widespread species that inhabited Java from 1.2 million years ago, and was also in China – this would also include “<a href="https://australianmuseum.net.au/homo-floresiensis">the Hobbit</a>” (<em>Homo floresiensis</em>) from Flores, which may be a <a href="https://theconversation.com/a-700-000-year-old-fossil-find-shows-the-hobbits-ancestors-were-even-smaller-60192">dwarfed <em>Homo erectus</em></a>. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-700-000-year-old-fossil-find-shows-the-hobbits-ancestors-were-even-smaller-60192">A 700,000-year-old fossil find shows the Hobbits’ ancestors were even smaller</a>
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<p>That said, it is now clear that Wallacea is a highly enigmatic region with a complex role in the human evolutionary story, so I would not rule out the possibility that an entirely unknown species inhabited Luzon.</p>
<h2>How did hominins get to Luzon?</h2>
<p>The Luzon team <a href="https://www.nature.com/articles/doi:10.1038/s41586-018-0072-8">concludes</a> that hominins of some kind had established a presence in the northern Philippines during the Middle Pleistocene epoch (between 781,000 and 126,000 years ago), that they must have come originally from Borneo to the southwest or Taiwan to the north, and that they could <em>potentially</em> have used boats. </p>
<p>I think most scientists will be reluctant to accept the idea of archaic hominins paddling beyond Eurasia in purpose-built watercraft, even very rudimentary ones. This is not to say that such a scenario is impossible, but I think if it were so then we would already have evidence that archaic hominins got to more remote parts of the region, including Australia. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/217000/original/file-20180501-135825-ce9xar.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/217000/original/file-20180501-135825-ce9xar.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/217000/original/file-20180501-135825-ce9xar.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/217000/original/file-20180501-135825-ce9xar.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/217000/original/file-20180501-135825-ce9xar.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/217000/original/file-20180501-135825-ce9xar.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/217000/original/file-20180501-135825-ce9xar.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">Excavations at the Kalinga site in the Cagayan Valley of Luzon.</span>
<span class="attribution"><span class="source">G.D. van den Bergh</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>It is more likely that rare events are the mechanism behind hominin populations taking root on oceanic islands near Asia, like Flores, Sulawesi, and Luzon: for instance, hominins may have been swept out to sea by tsunamis and survived ocean crossings by clinging to floating vegetation.</p>
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Read more:
<a href="https://theconversation.com/debris-from-the-2011-tsunami-carried-hundreds-of-species-across-the-pacific-ocean-84773">Debris from the 2011 tsunami carried hundreds of species across the Pacific Ocean</a>
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<h2>What this means for the “Hobbit” story</h2>
<p>The oldest stone tools on Flores <a href="http://www.abc.net.au/radionational/programs/scienceshow/tools-show-humans-in-flores-one-million-years-ago/3115264">date back at least one million years</a>. The earliest hominin fossils from this island <a href="https://www.theguardian.com/science/2016/jun/08/new-fossils-shed-light-evolution-hobbits-flores">are 700,000 years old</a> and belong to a Hobbit-like population that may be directly ancestral to <em>Homo floresiensis</em>. </p>
<p>The Luzon find is important to the Hobbit story because it now looks like the northern part of Wallacea was the source of origin for the hominin population that first reached Flores (via Sulawesi) on the southern fringes of Wallacea. </p>
<p>The “Hobbit trail” may begin in the Philippines!</p>
<p>The Flores fossils suggest that hominins cut off on this Wallacean island survived for hundreds of millennia and underwent unexpected evolutionary changes, including shrinking dramatically in both body and brain size. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=433&fit=crop&dpr=1 600w, https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=433&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=433&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=544&fit=crop&dpr=1 754w, https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=544&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/217175/original/file-20180502-153873-1rc6eh6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=544&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map of Southeast Asia and the wider region during the Late Pleistocene period.</span>
<span class="attribution"><span class="source">Adam Brumm</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>It is possible a similar story of hominins evolving in genetic isolation took place in Luzon; but, that said, the Luzon environments are distinct from those of Flores, so we can’t easily predict the outcome of a new evolutionary “experiment” with different parameters in this Wallacean island. </p>
<p>There may be some real surprises in store when a hominin fossil record is available in Luzon.</p>
<h2>Did “archaics” meet “moderns” in the Philippines?</h2>
<p>Finally, the biggest of big picture questions is whether archaic hominins in Flores and Luzon (and Sulawesi) persisted for long enough to come face-to-face with modern humans, who probably migrated into this area around <a href="https://www.nature.com/articles/nature23452">70,000 years ago</a>. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/worlds-scientists-turn-to-asia-and-australia-to-rewrite-human-history-88697">World's scientists turn to Asia and Australia to rewrite human history</a>
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<p>We now know from ancient DNA studies that our species <a href="https://theconversation.com/worlds-scientists-turn-to-asia-and-australia-to-rewrite-human-history-88697">interbred</a> with at least two (but probably more) archaic hominin species encountered by modern humans outside Africa: Neanderthals and Denisovans. </p>
<p>Could there have been other gene flow events involving unique populations of archaic humans scattered throughout Wallacea? </p>
<p>We don’t yet know the answer to that question.</p><img src="https://counter.theconversation.com/content/95879/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Brumm receives funding from the Australian Research Council.</span></em></p>Humans butchered a rhino in a remote part of the Philippines 700,000 years ago, but who were they and how did they get there?Adam Brumm, ARC Future Fellow, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.