tag:theconversation.com,2011:/uk/topics/woolly-mammoth-1837/articles
Woolly mammoth – The Conversation
2023-06-14T12:35:28Z
tag:theconversation.com,2011:article/205556
2023-06-14T12:35:28Z
2023-06-14T12:35:28Z
Forensic evidence suggests Paleo-Americans hunted mastodons, mammoths and other megafauna in eastern North America 13,000 years ago
<figure><img src="https://images.theconversation.com/files/528316/original/file-20230525-21-no8djo.jpg?ixlib=rb-1.1.0&rect=556%2C160%2C3570%2C2456&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Animals that shared the landscape with humans disappeared as the ice age ended.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Ice_age_fauna_of_northern_Spain_-_Mauricio_Antón.jpg">Mauricio Antón/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>The earliest people who lived in North America shared the landscape with huge animals. On any day these hunter-gatherers might encounter a giant, snarling saber-toothed cat ready to pounce, or a group of elephantlike mammoths stripping tree branches. Maybe a herd of giant bison would stampede past.</p>
<p>Obviously, you can’t see any of these ice age megafauna now. They’ve all been extinct for about 12,800 years. Mammoths, mastodons, huge bison, horses, camels, very large ground sloths and giant short-faced bears all died out as the huge continental ice sheets disappeared at the end of the ice age. What happened to them?</p>
<p>Scientists have pointed to various potential causes for the extinctions. Some suggest <a href="https://doi.org/10.1038/s41467-021-21201-8">environmental changes happened faster</a> than the animals could adapt to them. Others posit a <a href="https://doi.org/10.1073/pnas.0706977104">catastrophic impact of a fragmented comet</a>. Maybe it was <a href="https://doi.org/10.1073/pnas.0501947102">overhunting on the part of humans</a>, or <a href="https://doi.org/10.1146/annurev.ecolsys.34.011802.132415">some combination of all these factors</a>.</p>
<p><a href="https://sc.edu/study/colleges_schools/artsandsciences/sc_institute_archeology_and_anthropology/faculty-staff/moore_christopher.php">One of my major interests as an archaeologist</a> has been to understand how the earliest Paleo-Americans lived and interacted with megafauna species. Just how implicated should humans be in the extinction of these ice age animals? In a new study, my colleagues and I used a forensic technique more commonly used to identify blood on objects at crime scenes <a href="https://doi.org/10.1038/s41598-023-36617-z">to investigate this question</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Artist's rendition of Paleoamerican Clovis encampment with people sitting around campfire under night sky" src="https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528320/original/file-20230525-19-5p0no3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Clovis hunter-gatherers lived in small, mobile groups, likely following animal migrations over long distances.</span>
<span class="attribution"><span class="source">Martin Pate/Southeast Archeological Center, National Park Service</span></span>
</figcaption>
</figure>
<h2>Testing stone tools like murder weapons</h2>
<p>Archaeologists have uncovered a sparse scattering of stone tools left at the campsites of Paleo-American Clovis hunter-gatherers who lived around the time of the megafauna extinctions. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="line drawing of two stone points" src="https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=682&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=682&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=682&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=857&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=857&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531835/original/file-20230614-25-wuuy96.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=857&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Early Paleo-American Clovis points (left) and Middle Paleo-American redstone points (right) have a distinct fluted shape, highlighted in yellow, likely designed to facilitate hafting onto a spear or knife handle for use in hunting and butchery.</span>
<span class="attribution"><span class="source">Darby Erd</span></span>
</figcaption>
</figure>
<p>These include iconic <a href="https://www.britannica.com/topic/Clovis-complex">Clovis spearpoints</a> with their distinctive flutes – concave areas left behind by removed stone flakes that extend from the base to the middle of the point. People most likely made the points this way so they could easily affix them to a spear shaft.</p>
<p>Based on <a href="https://www.heritagedaily.com/2016/02/an-afternoon-walk-and-a-mammoth-find-second-clovis-people-kill-site-found-in-new-mexico/109750">sites excavated in the western United States</a>, archaeologists know Paleo-American Clovis hunter-gatherers who lived around the time of the extinctions at least occasionally killed or scavenged ice age megafauna such as mammoths. There they’ve found preserved bones of megafauna together with the stone tools used for killing and butchering these animals. These sites are crucial for understanding the possible role that early Paleo-Americans played in the extinction event.</p>
<p>Unfortunately, many areas in the Southeastern United States lack sites with preserved bone and associated stone tools that might indicate whether megafauna were hunted there by Clovis or other Paleo-American cultures. Without evidence of preserved bones of megafauna, archaeologists have to find other ways to examine this question.</p>
<p>Forensic scientists have used an <a href="https://www.ojp.gov/ncjrs/virtual-library/abstracts/use-crossover-immunoelectrophoresis-detect-human-blood-protein-soil">immunological blood residue analysis</a> technique called <a href="https://doi.org/10.1016/0379-0738(78)90025-7">immunoelectrophoresis</a> for over 50 years to identify blood residue sticking to objects found at crime scenes. In recent years, researchers have applied this method to identify <a href="https://doi.org/10.1016/j.jasrep.2022.103785">animal blood proteins preserved within ancient stone tools</a>. They compare aspects of the ancient blood with blood antigens derived from modern relatives of extinct animals.</p>
<p>Residue analysis does not rely on the presence of nuclear DNA, but rather on preserved, identifiable proteins that sometimes survive <a href="https://doi.org/10.1006/jasc.2000.0628">within the microscopic fractures and flaws of stone tools</a> created during their manufacture and use. Typically, only a small percentage of artifacts produce <a href="https://library-archives.canada.ca/eng/services/services-libraries/theses/Pages/item.aspx?idNumber=27681369">positive blood residue results</a>, indicating a match between the ancient residue and antiserum molecules from modern animals.</p>
<p><a href="https://www.postandcourier.com/aikenstandard/news/a-lot-of-unknowns/article_95d93585-8455-5af6-b9e1-536b629f49ee.html">A previous blood residue study</a> of a small number of Paleo-American artifacts in South Carolina and Georgia failed to provide evidence that these people had hunted or scavenged extinct megafauna. The researchers found evidence of bison and other animals such as deer, bear and rabbit, but no evidence of Proboscidean (mammoth or mastodon) or of an extinct species of North American horse.</p>
<h2>Identifying ancient prey of human hunters</h2>
<p>My colleagues and I realized we needed a much larger sample of Paleo-American stone tools for testing. Since Clovis points and other Paleo-American artifacts are rare, I relied heavily on local museums, private collectors, collections housed at state universities and even military installations to amass a sample of 120 Paleo-American stone tools from all over North Carolina and South Carolina.</p>
<p>Because these artifacts are irreplaceable, I personally carried all 120 Clovis spearpoints and tools inside a protective case on a flight from South Carolina to the blood residue lab in Portland, Oregon. I coordinated in advance with the Transportation Security Administration so my collection of 13,000-year-old weaponry would make it through the screening process.</p>
<p>The blood residue analysis provided unambiguous proof that the tools had had contact with ancient animal blood proteins. The results included the first direct evidence on ancient stone tools of the blood of extinct mammoth or mastodon (Proboscidean) and the extinct North American horse (Equidae) on Paleo-American artifacts in eastern North America. This evidence is significant because it proves that these animals were present in the Carolinas, and they were hunted or scavenged by early Paleo-Americans.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="artist's rendition of prehistoric people hitting a mastodon with spears" src="https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528323/original/file-20230525-23-9vbnei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It likely would have taken a group of hunters to take down a mastodon.</span>
<span class="attribution"><a class="source" href="https://georgiainfo.galileo.usg.edu/gastudiesimages/Mastodon%20Hunt%201.htm">Ed Jackson</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>In addition to Proboscidean and horse, bison (Bovidae) blood residues were most common, adding to earlier blood residue research <a href="https://doi.org/10.7183/0002-7316.81.1.132">suggesting a focus on bison hunting</a> by Clovis and other Paleo-American cultures. Bison in North America did not go extinct but <a href="https://en.wikipedia.org/wiki/Bison_antiquus">instead became smaller</a>, most likely as a result of climate change as the last ice age ended and the climate warmed.</p>
<p>So, what do these results suggest for the extinction debate? While this study does not prove humans were responsible for the extinctions, it does show that early Paleo-Americans across the continent likely hunted or scavenged these animals, at least occasionally. The results also indicate that Proboscideans and horses were around when Clovis people were here – only a few hundred years before their eventual extinction in North America.</p>
<p>Another interesting finding is that while Proboscidean blood residues are found on Clovis artifacts, blood residues for horses (Equidae) are found on both Clovis and Paleo-American points that are slightly more recent younger than Clovis. This may suggest the extinction of Proboscidean was complete in the Carolinas by the end of the Clovis period, and the extinction of ice age horse species took longer.</p>
<p>Testing an even larger sample of Paleo-American stone tools from different regions of North America could help pin down the timing and geographic variability in the extinction of megafauna species and provide more clues about why these animals disappeared when they did.</p><img src="https://counter.theconversation.com/content/205556/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher R. Moore is affiliated with the the non-profit Comet Research Group (CRG).</span></em></p>
A forensic technique more often used at modern crime scenes identified blood residue from large extinct animals on spearpoints and stone tools used by people who lived in the Carolinas millennia ago.
Christopher R. Moore, Research Professor and Director of the Southeastern Paleoamerican Survey (SEPAS) at the South Carolina Institute for Archaeology and Anthropology, University of South Carolina
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/190146
2022-09-09T06:37:38Z
2022-09-09T06:37:38Z
Curious Kids: did humans hunt and eat woolly mammoths or dinosaurs?
<figure><img src="https://images.theconversation.com/files/483641/original/file-20220909-16-m8wj9l.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C1610%2C802&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Blue Sky Studios/AP</span></span></figcaption></figure><blockquote>
<p>Did humans hunt and eat woolly mammoths or dinosaurs? – Jasmine, age 10, Central Coast NSW</p>
</blockquote>
<p>Hi Jasmine, </p>
<p>Thanks for this great question! </p>
<p>Humans can be blamed for a lot of things: chopping down rainforests, worsening climate change, and driving precious species like the Tasmanian Tiger to extinction. But can we add hunting and eating woolly mammoths and dinosaurs to the list?</p>
<p>Well, we can safely assume dinosaurs never fell prey to humans – mainly because the two never even met (despite what the Jurassic Park films suggest). Dinosaurs had already been extinct for about 62 million years by the time modern humans started roaming the planet!</p>
<p>But what about woolly mammoths? In this case, the movie Ice Age was actually correct. Humans and woolly mammoths lived side by side for <a href="https://doi.org/10.1016/S0277-3791(02)00026-4">at</a> <a href="https://doi.org/10.1002/evan.21478">least</a> 15,000 years.</p>
<h2>Mammoth findings in the fossil record</h2>
<p>So did humans hunt woolly mammoths to extinction? To answer this question we must look at clues in the fossil record, which is made up of the preserved remains of ancient life.</p>
<p>In the case of the dodo, a large flightless bird that went <a href="https://www.newscientist.com/article/mg24432611-300-the-curious-life-and-surprising-death-of-the-last-dodo-on-earth/">extinct</a>, documents from 1690 make it clear that over-hunting by humans was the cause.</p>
<figure class="align-right ">
<img alt="A model of a dodo stand atop a museum display." src="https://images.theconversation.com/files/483687/original/file-20220909-16-5ynav2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/483687/original/file-20220909-16-5ynav2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=621&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483687/original/file-20220909-16-5ynav2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=621&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483687/original/file-20220909-16-5ynav2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=621&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483687/original/file-20220909-16-5ynav2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=780&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483687/original/file-20220909-16-5ynav2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=780&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483687/original/file-20220909-16-5ynav2.jpeg?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">
<figcaption>
<span class="caption">The dodo was first discovered on the island of Mauritius in the late 1500s.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Dodo#/media/File:Oxford_Dodo_display.jpg">Wiki Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>But woolly mammoths were around long before we had paper to write on. They existed from about 300,000 years ago – a time when ice covered the northern parts of the world. </p>
<p>As for when they went extinct, a small number of dwarf mammmoths <a href="https://www.nature.com/articles/362337a0">survived</a> on a little isolated island in the Arctic until about 4,000 years ago. But the full-sized species disappeared from an area called Beringia (located between Siberia and Alaska) some 12,000 years ago – after living alongside humans for at least 15,000 years.</p>
<p>Did humans kill them off? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=325&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=325&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=325&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=408&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=408&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483640/original/file-20220909-12-1uq3wz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=408&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 2002 film Ice Age showed a face-off between Manny the woolly mammoth and a human.</span>
<span class="attribution"><span class="source">Twentieth Century Fox/IMDB</span></span>
</figcaption>
</figure>
<h2>Hunting for clues</h2>
<p>When early humans hunted, they tended to kill many animals at the same time. This created “kill sites”, which are literally huge piles of animal bones. And when they pulled the meat off the bones to eat, they used stone tools that created cut marks or small notches in the bones.</p>
<p>These marks now provide vital clues. In Beringia, there is fossil evidence for mammoth kill sites, and cut marks on mammoth bones – so all the clues point to humans having hunted woolly mammoths. </p>
<p>But the strongest evidence <a href="https://www.sciencedirect.com/science/article/abs/pii/S0277379118308588">was found</a> in southern Poland in 2019. A small part of a stone tool, made into a spear blade by a human, was found in the rib bone of a woolly mammoth. If this was evidence presented in a murder trial, that human would be locked up straight away!</p>
<p>Even so, does that mean humans alone were responsible for wiping out all the full-sized woolly mammoths?</p>
<p>Some scientists <a href="https://doi.org/10.1371/journal.pbio.0060079">suggest</a> the climate also played a role. </p>
<p>It could be that climate conditions at the time shifted away from what woolly mammoths preferred and caused a large drop in their numbers.
This may have made the remaining mammoths more vulnerable to increasing hunting as the human population grew.</p>
<h2>Australia’s own ‘mammoths’</h2>
<p>Australia didn’t have woolly mammoths. They would have gotten very hot in those thick coats! But we did have giant animals known as megafauna, which went extinct between 5,000 and 17,000 years (depending on the species) after the First Peoples arrived.</p>
<p>Interestingly, we don’t find any reliable fossil evidence of these people hunting Australia’s <a href="https://theconversation.com/meet-the-giant-wombat-relative-that-scratched-out-a-living-in-australia-25-million-years-ago-141296">ancient</a> <a href="https://theconversation.com/this-giant-kangaroo-once-roamed-new-guinea-descended-from-an-australian-ancestor-that-migrated-millions-of-years-ago-185778">megafauna</a>. There are no known kill sites, no cut marks on the animal bones, and no evidence of spear blades being lodged in ribs.</p>
<p>Was the megafauna’s disappearance related to human activity? Or did climate change play a part here as well? </p>
<p>The jury is still out on this one! But the more fossils we find, and the better we get at studying them, the closer we’ll come to understanding what happened all those years ago.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-could-dinosaurs-evolve-back-into-existence-148623">Curious Kids: could dinosaurs evolve back into existence?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/190146/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kira Westaway receives funding from the Australian Research Council</span></em></p>
All the evidence points to one thing: humans and woolly mammoths certainly lived side by side. But did humans hunt mammoths too?
Kira Westaway, Associate Professor, School of Natural Sciences, Macquarie University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/178425
2022-03-08T19:01:13Z
2022-03-08T19:01:13Z
Can we resurrect the thylacine? Maybe, but it won’t help the global extinction crisis
<figure><img src="https://images.theconversation.com/files/450572/original/file-20220308-85746-1gwxayr.jpeg?ixlib=rb-1.1.0&rect=208%2C343%2C3660%2C2618&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">NFSA</span></span></figcaption></figure><p>Last week, researchers at the University of Melbourne <a href="https://findanexpert.unimelb.edu.au/news/40441-the-9-steps-to-de-extincting-australia%E2%80%99s-thylacine">announced</a> that <a href="https://www.nma.gov.au/explore/collection/highlights/thylacine">thylacines</a> or Tasmanian tigers, the Australian marsupial predators extinct since the 1930s, could one day be ushered back to life. </p>
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<img alt="" src="https://images.theconversation.com/files/450201/original/file-20220306-83366-zqlo3y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/450201/original/file-20220306-83366-zqlo3y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=725&fit=crop&dpr=1 600w, https://images.theconversation.com/files/450201/original/file-20220306-83366-zqlo3y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=725&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/450201/original/file-20220306-83366-zqlo3y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=725&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/450201/original/file-20220306-83366-zqlo3y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=911&fit=crop&dpr=1 754w, https://images.theconversation.com/files/450201/original/file-20220306-83366-zqlo3y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=911&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/450201/original/file-20220306-83366-zqlo3y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=911&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 thylacine (<em>Thylacinus cynocephalus</em>), also known as the ‘Tasmanian tiger’ (it was neither Tasmanian, because it was once common in mainland Australia, nor was it related to the tiger), went extinct in Tasmania in the 1930s from persecution by farmers and habitat loss. Art by Eleanor (Nellie) Pease, University of Queensland.</span>
<span class="attribution"><span class="source">Centre of Excellence for Australian Biodiversity and Heritage</span></span>
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<p>The main reason for the optimism was the receipt of a <a href="https://about.unimelb.edu.au/newsroom/news/2022/march/no-longer-science-fiction-$5m-gift-brings-de-extinction-of-the-thylacine-one-step-closer">A$5 million philanthropic donation</a> to the <a href="https://findanexpert.unimelb.edu.au/profile/4401-andrew-pask">research team</a> behind the endeavour.</p>
<p>Advances in <a href="https://www.nature.com/articles/s41559-017-0417-y">mapping the genome of the thylacine</a> and its living relative <a href="https://theconversation.com/weve-decoded-the-numbat-genome-and-it-could-bring-the-thylacines-resurrection-a-step-closer-176528">the numbat</a> have made the prospect of re-animating the species seem real. As an ecologist, I would personally relish the opportunity to see a living specimen.</p>
<p>The announcement led to some <a href="https://www.dailymail.co.uk/news/article-10567003/Tasmanian-tiger-brought-LIFE-new-plan.html">overhyped headlines</a> about the imminent resurrection of the species. But the idea of “<a href="https://e360.yale.edu/features/the_case_against_de-extinction_its_a_fascinating_but_dumb_idea">de-extinction</a>” faces a variety of technical, ethical and ecological challenges. Critics (like myself) argue it diverts attention and resources from the urgent and achievable task of preventing still-living species from becoming extinct.</p>
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<h2>The rebirth of the bucardo</h2>
<p>The idea of de-extinction goes back at least to the creation of the San Diego <a href="https://science.sandiegozoo.org/resources/frozen-zoo%C2%AE">Frozen Zoo</a> in the early 1970s. This project aimed to freeze blood, DNA, tissue, cells, eggs and sperm from exotic and endangered species in the hope of one day recreating them.</p>
<p>The notion gained broad public attention with the first of the <a href="https://www.imdb.com/title/tt0107290/">Jurassic Park</a> films in 1993. The famous <a href="https://www.nature.com/articles/385810a0">cloning of Dolly the sheep</a> reported in 1996 created a sense that the necessary know-how wasn’t too far off.</p>
<p>The next technological leap came in 2008, with the <a href="https://www.pnas.org/doi/10.1073/pnas.0806166105">cloning of a dead mouse</a> that had been frozen at –20°C for 16 years. If frozen individuals could be cloned, re-animation of a whole species seemed possible.</p>
<p>After this achievement, de-extinction began to look like a potential way to tackle the modern <a href="https://conservationbytes.com/2022/03/02/the-sixth-mass-extinction-is-happening-now-and-it-doesnt-look-good-for-us/">global extinction crisis</a>.</p>
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<strong>
Read more:
<a href="https://theconversation.com/worried-about-earths-future-well-the-outlook-is-worse-than-even-scientists-can-grasp-153091">Worried about Earth's future? Well, the outlook is worse than even scientists can grasp</a>
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<p>Another notable advance came in 2009, when a subspecies of Pyrenean ibex known as the <em>bucardo</em> (<em>Capra pyrenaica pyrenaica</em>) which had been extinct since 2000 was cloned using <a href="https://www.sciencedirect.com/science/article/pii/S0093691X08007784?via%3Dihub">frozen tissue</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/450198/original/file-20220306-16533-13t9ba2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/450198/original/file-20220306-16533-13t9ba2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/450198/original/file-20220306-16533-13t9ba2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/450198/original/file-20220306-16533-13t9ba2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/450198/original/file-20220306-16533-13t9ba2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/450198/original/file-20220306-16533-13t9ba2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/450198/original/file-20220306-16533-13t9ba2.jpeg?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">Iberian ibex (<em>Capra pyrenaica</em>), or <em>cabra montés</em> in Spanish. Author: Juan Lacruz.</span>
<span class="attribution"><span class="source">https://commons.wikimedia.org/wiki/File:Cabra_mont%C3%A9s_4.jpg</span></span>
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<p>The newborn bucardo died only a few minutes after birth. But it could no longer be argued that de-extinction was limited to the imagination.</p>
<h2>Leaving no stone unturned</h2>
<p>There are still some technical reasons to think genuine de-extinction <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2435.12705">might never be possible for many species</a>. But even if these are overcome, the debate over pros and cons will continue. </p>
<p><a href="https://cosmosmagazine.com/nature/evolution/thylacine-tasmanian-tiger-de-extinction/">Proponents argue</a> that with the accelerating loss of species today, we must exploit all options. In isolation, de-extinction seems like a sensible tool to add to our anti-extinction kit.</p>
<p>But it’s far from that simple. Opponents have a long list of reasons why de-extinction won’t help to save biodiversity.</p>
<h2>An expensive project</h2>
<p>One of the main arguments against de-extinction is the huge expense required for research and technology. The A$5 million donated to the University of Melbourne is only a drop in the bucket.</p>
<p>Ecologists and conservation biologists argue the money would be <a href="https://www.nature.com/articles/s41559-016-0053">better spent on initiatives to prevent extinction</a> in the first place. These include <a href="https://www.bushheritage.org.au/what-we-do/buying-land">purchasing land to conserve entire ecosystems</a>, removing <a href="https://theconversation.com/invasive-species-are-australias-number-one-extinction-threat-116809">invasive species</a>, <a href="https://theconversation.com/australia-could-green-its-degraded-landscapes-for-just-6-of-what-we-spend-on-defence-168807">restoring damaged habitats</a>, and programs to <a href="https://theconversation.com/zoos-arent-victorian-era-throwbacks-theyre-important-in-saving-species-78533">breed</a> and <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/species-reintroduction">re-introduce</a> threatened species.</p>
<p>On the other hand, if someone wants to <a href="http://doi.org/10.21425/F5FBG19504">spend the money on the tech</a>, why not let it happen? After all, people <a href="https://www.bbc.com/news/science-environment-42992143">waste a lot more</a> on arguably sillier ventures.</p>
<p>However, modelling suggests spending limited resources on de-extinction <a href="https://www.nature.com/articles/s41559-016-0053">could lead to net biodiversity loss</a>.</p>
<h2>Prevention is better than cure</h2>
<p>Another common argument is that <a href="https://www.discovermagazine.com/environment/maybe-extinction-isnt-forever-is-that-a-good-thing">prevention is better than cure</a>; we should put all our efforts into avoiding extinction in the first place. </p>
<p>If we believe we can somehow “fix extinction later”, we risk becoming ambivalent. Planning for conservation after the fact could be a dangerous road to apathy and higher net extinction rates.</p>
<h2>‘Playing God’</h2>
<p>Some have argued that the mere concept of de-extinction <a href="https://link.springer.com/article/10.1007/s11569-014-0201-2">tests the limits of our ethical notions</a>. </p>
<p>“Playing God” with the existence of whole species is inherently contentious. Research and implementation depend on <a href="https://link.springer.com/article/10.1007/s11569-014-0201-2">value judgements</a>, with those in power realising their values above those of others. </p>
<p>Will the voices of Indigenous peoples be heard when deciding on what species to resurrect? Will the dispossessed and poor also have a say?</p>
<p>There are also serious questions of <a href="https://link.springer.com/article/10.1007/s10806-018-9755-2">animal welfare</a> both along the pathway to de-extinction, as well as what happens to the organisms once created (including in captivity and after re-introduction to the wild).</p>
<h2>A question of numbers</h2>
<p>Perhaps the most important practical argument against de-extinction, but also the most overlooked, is that creating one or two animals won’t be nearly enough to bring back a species.</p>
<p>To have any real chance of surviving in the wild, introduced populations need to <a href="http://doi.org/10.1016/j.biocon.2013.12.036">number in the hundreds, if not thousands</a>. Could we make enough individuals to do this?</p>
<p>We would also need to <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/zsc.12212">increase the genetic diversity</a> of the individuals via <a href="https://www.newscientist.com/definition/what-is-crispr/">gene editing</a>, as has been done in a limited way for <a href="https://academic.oup.com/hr/article/doi/10.1038/s41438-020-0258-8/6445456">a few species of crop plants</a>. </p>
<p>But even so, we know <a href="https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1111/acv.12534">most re-introductions of threatened species fail</a> because of insufficient numbers. </p>
<h2>Living space</h2>
<p>Let’s say we ignore the technological challenges, the costs, the ethics, the lack of genetic diversity, and so on. Assume we can make new thylacines, <a href="https://ucmp.berkeley.edu/mammal/mammoth/about_mammoths.html">mammoths</a>, <a href="https://australian.museum/learn/australia-over-time/extinct-animals/diprotodon-optatum/">diprotodons</a>, or <a href="http://www.prehistoric-wildlife.com/species/s/smilodon.html">sabre-tooth cats</a>. Great. Now where do we put them?</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/450186/original/file-20220306-44826-s70knx.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"></a>
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<span class="caption"><em>Diprotodon optimum</em>. The rhino-sized ‘wombat’ from Australia that died out over 40,000 years ago. Art by Eleanor (Nellie) Pease, University of Queensland.</span>
<span class="attribution"><span class="source">Centre of Excellence for Australian Biodiversity and Heritage</span></span>
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<p>Humans have destroyed <a href="https://www.nature.com/articles/nature25138">at least half of Earth’s vegetation</a> since the agricultural revolution. We have altered almost <a href="https://ipbes.net/global-assessment">two-thirds of Earth’s land surface</a> to some degree. </p>
<p>As a result, about <a href="https://www.un.org/sustainabledevelopment/blog/2019/05/nature-decline-unprecedented-report/">1 million</a> plant and animal species are threatened with extinction, and the total number of vertebrates in the wild has fallen by <a href="https://www.worldwildlife.org/publications/living-planet-report-2020">two-thirds</a> since the 1970s. </p>
<p>Available living space is in short supply, especially for big species that require a lot of intact territory to survive.</p>
<p>Not to mention human-wildlife conflicts. </p>
<p>What happens if a major predator (such as the thylacine) is put back? Will pastoralists welcome them with open arms, or <a href="https://theconversation.com/the-tasmanian-tiger-was-hunted-to-extinction-as-a-large-predator-but-it-was-only-half-as-heavy-as-we-thought-144599">shoot them to extinction as they did last time</a>? </p>
<p>From <a href="https://africageographic.com/stories/human-lion-conflict-in-a-key-lion-population-area/">lions</a> to <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.12117">bears</a>, <a href="https://www.conservationindia.org/articles/human-tiger-conflict-cause-consequence-and-mitigation">tigers</a> to <a href="https://www.sciencedirect.com/science/article/abs/pii/S0006320716307625">jaguars</a>, and <a href="https://theconversation.com/will-we-hunt-dingoes-to-the-brink-like-the-tasmanian-tiger-19982">dingoes</a>, predators the world over are still heavily persecuted because they compete with human enterprise.</p>
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<strong>
Read more:
<a href="https://theconversation.com/will-we-hunt-dingoes-to-the-brink-like-the-tasmanian-tiger-19982">Will we hunt dingoes to the brink like the Tasmanian tiger?</a>
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<h2>The world has changed</h2>
<p>If we did return extinct species to the places where they used to live, there is no guarantee they would survive there in modern conditions. Climate change and other processes mean that <a href="http://doi.org/10.3897/rethinkingecology.4.32570">many past environmental states no longer exist</a>. </p>
<p>Just because a mammoth lived in Siberia 20,000 years ago doesn’t mean it could necessarily do so today.</p>
<h2>Diseases and invasions</h2>
<p>There are already debates underway about moving threatened species to new habitats to increase their chances of survival. Opponents of this “<a href="https://theconversation.com/why-climate-change-is-forcing-conservationists-to-be-more-ambitious-by-moving-threatened-species-to-pastures-new-163749">assisted migration</a>” point out the risk of spreading disease or parasites, or that the moved species will harm other species in their new home.</p>
<p>Now imagine you want to introduce a species that has long been extinct to an area. Would it spread disease or knock off other species?</p>
<p>On the flip side, most species rely on highly specialised microbiomes for survival. Recently resurrected species might be <a href="https://www.sciencedirect.com/science/article/pii/S1617138120300844">missing these organisms</a> or succumb to the ones living in the area where they are released.</p>
<h2>The debate isn’t going away</h2>
<p>As technology continues to advance, we will likely see many leaps toward the holy grail of resurrecting extinct species. Chances are it will be a recently extinct species rather than something like a diprotodon, or dare I say, a dinosaur.</p>
<p>But even so, de-extinction is unlikely to offer any real value to the overall conservation of biodiversity.</p>
<p>Should we therefore continue to pursue de-extinction? The debate isn’t going to disappear anytime soon. As long as there are punters willing to fund the technological research, the pursuit will continue. </p>
<p>But even the most amazing technological advances are unlikely to help the <a href="https://www.frontiersin.org/articles/10.3389/fcosc.2020.615419/full">catastrophic worldwide loss of biodiversity</a>.</p><img src="https://counter.theconversation.com/content/178425/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Corey J. A. Bradshaw receives funding from the Australian Research Council. </span></em></p>
‘De-extinction’ seems like a way to save dying or dead species - but in reality it’s an expensive and impractical waste of time.
Corey J. A. Bradshaw, Matthew Flinders Professor of Global Ecology and Models Theme Leader for the ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/146073
2022-01-23T13:44:19Z
2022-01-23T13:44:19Z
Ancient DNA suggests woolly mammoths roamed the Earth more recently than previously thought
<figure><img src="https://images.theconversation.com/files/442067/original/file-20220123-17253-1q5eenk.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6607%2C2106&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Genetic material found in permafrost sediments from the Yukon contains rich information about ancient ecosystems.</span> <span class="attribution"><span class="source">(Julius Csotonyi/Government of Yukon)</span>, <span class="license">Author provided</span></span></figcaption></figure><iframe style="width: 100%; height: 175px; border: none; position: relative; z-index: 1;" allowtransparency="" src="https://narrations.ad-auris.com/widget/the-conversation-canada/ancient-dna-suggests-woolly-mammoths-roamed-the-earth-more-recently-than-previously-thought" width="100%" height="400"></iframe>
<p>In 2010, small cores of permafrost sediments were collected by a team at the <a href="https://cms.eas.ualberta.ca/froeselab/">University of Alberta</a> from <a href="https://www.nps.gov/yuch/learn/historyculture/placer-mining.htm">gold mines</a> in the Klondike region of central Yukon. They had remained in cold storage until paleogeneticists at the <a href="https://socialsciences.mcmaster.ca/mcmaster-ancient-dna-centre">McMaster Ancient DNA Centre</a> applied new genomics techniques to better understand the <a href="https://doi.org/10.1002/gj.2633">global extinction of megafauna that had culminated in North America some 12,700 years ago</a>.</p>
<p>These tiny sediment samples contain an immense wealth of ancient environmental DNA from innumerable plants and animals that lived in those environments over millennia. These genetic microfossils originate from all components of an ecosystem — including bacteria, fungi, plants and animals — and serve as a time capsule of long-lost ecosystems, such as the <a href="https://pleistocenepark.ru/science/">mammoth-steppe</a>, which disappeared around 13,000 years ago.</p>
<p>How exactly these ecosystems restructured so significantly, and why large animals seem to have been the most impacted by this shift has been an <a href="https://doi.org/10.2307/1005126">active area of scientific debate since the 18th century</a>. </p>
<p>We can now use environmental DNA to help fill the gaps that have driven this debate.</p>
<h2>Ancient DNA, cutting-edge technologies</h2>
<p>Bacterial, fungal and unidentifiable DNA make up over 99.99 per cent of an environmental sample. In our case, we wanted a way to selectively recover the much smaller fraction of ancient plant and animal DNA that would help us better understand the collapse of the mammoth-steppe ecosystem.</p>
<p>For my <a href="http://hdl.handle.net/11375/26197">doctoral research</a>, I was part of a team that developed a <a href="https://doi.org/10.1017/qua.2020.59">a new technique to extract, isolate, sequence and identify tiny fragments of ancient DNA from sediment</a>.</p>
<p>We analyzed these DNA fragments to track the shifting cast of plants and animals that lived in central Yukon over the past 30,000 years. <a href="https://doi.org/10.1017/qua.2020.59">We found evidence</a> for the late survival of woolly mammoths and horses in the Klondike region, some 3,000 years later than expected.</p>
<p>We then <a href="https://doi.org/10.1038/s41467-021-27439-6">expanded our analysis</a> to include 21 previously collected permafrost cores from four sites in the Klondike region that date between 4,000 to 30,000 years ago.</p>
<p>With current technologies, we not only could identify which organisms a set of genetic microfossils came from. But we <a href="https://doi.org/10.1016/j.cub.2021.12.023">were also able to reassemble</a> those fragments into genomes to study their evolutionary histories — solely from sediment.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Synthesis of genetic and fossil evidence" src="https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=496&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=496&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=496&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=624&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=624&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442016/original/file-20220121-17-1wtpnht.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=624&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Synthesis of dated bones, ancient environmental DNA and archaeological sites in Yukon and Alaska.</span>
<span class="attribution"><span class="source">(Tyler J. Murchie)</span></span>
</figcaption>
</figure>
<h2>Tremendous environmental change</h2>
<p>The <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/pleistocene-holocene-boundary">Pleistocene-Holocene transition, which occurred about 11,700 years ago,</a> was a period of tremendous change across the globe. In <a href="https://www.beringia.com/exhibits/beringia">eastern Beringia (the former Eurasian land bridge and unglaciated regions of Yukon and Alaska)</a>, this period saw the collapse of the <a href="https://doi.org/10.1016/j.quascirev.2012.10.005">mammoth-steppe biome</a> and its gradual replacement with the <a href="https://www.nrcan.gc.ca/our-natural-resources/forests/sustainable-forest-management/boreal-forest/13071">boreal forest</a> as we know it today. </p>
<p>This brought about the loss of iconic ice age megaherbivores like the <a href="https://www.beringia.com/exhibit/ice-age-animals/woolly-mammoth">woolly mammoth</a>, <a href="https://www.beringia.com/exhibit/ice-age-animals/yukon-horse">Yukon horse,</a> and <a href="https://www.beringia.com/exhibit/ice-age-animals/steppe-bison">steppe bison</a>, along with predators such as the <a href="https://www.beringia.com/exhibit/ice-age-animals/american-scimitar-cat">American scimitar cat</a> and <a href="https://www.beringia.com/exhibit/ice-age-animals/beringian-lion">Beringian lion</a>, among many others.</p>
<p>We found ancient environmental DNA from a diverse spectrum of ancient fauna, <a href="https://doi.org/10.1038/s41467-021-27439-6">including woolly mammoths, horses, steppe bison, caribou, rodents, birds and many other animals</a>.</p>
<p>We were also able to observe how ecosystems shifted with the rise of woody shrubs around 13,500 years ago, and how that correlated with a decline of DNA from woolly mammoths, horses and steppe bison. With this remarkably rich dataset, we observed four main findings.</p>
<ol>
<li><p>There was a surprising consistency in the signal between sites, suggesting our data was representative of ecological trends in the region.</p></li>
<li><p>Woolly mammoth DNA declines prior to the <a href="https://doi.org/10.1029/2005JD006079">Bølling–Allerød warming</a>, a warm period at the end of the last ice age, suggesting that megafaunal losses may have been staggered. </p></li>
<li><p><a href="https://albertaplantid.ca/forb-species/">Forbs (herbaceous flowering plants)</a> make up a substantial component of the mammoth-steppe ecosystem alongside grasses. </p></li>
<li><p>There is a consistent signal of woolly mammoth and Yukon horse persistence into the Holocene, as much as 7,000 years after their disappearance from fossil records.</p></li>
</ol>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Comparing equid genomes reconstructed from sediments and bone" src="https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=698&fit=crop&dpr=1 600w, https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=698&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=698&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=877&fit=crop&dpr=1 754w, https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=877&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/439574/original/file-20220105-27-1e1pnkn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=877&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 evolutionary tree showing the location and relationship of horses and their relatives with genomes reconstructed from bones and sediment.</span>
<span class="attribution"><span class="source">(Tyler J.Murchie)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>When paired with other records, our genetic reconstructions suggest that the transition out of the last glacial period may have been more drawn out than dated bones alone would suggest.</p>
<p>Mammoths, for example, may have declined in local population abundance thousands of years earlier than other megafauna, which is potentially correlated with the first <a href="https://doi.org/10.1371/journal.pone.0169486">controversial evidence</a> of humans in the area. Further, <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/refugium">grassland grazing animals may have persisted for thousands of years in refugia (habitats that support the existence of an isolated population)</a>, despite the environmental shift.</p>
<h2>Woolly mammoths alongside humans</h2>
<p>Our data suggest that horses and woolly mammoths may have persisted in the Klondike until approximately 9,000 years ago and perhaps as recently as 5,700 years ago, outliving their supposed disappearance from <a href="https://doi.org/10.1073/pnas.2107977118">local fossil records by 7,000 years</a>. However, it is possible for <a href="https://doi.org/10.1111/j.1502-3885.2010.00181.x">ancient environmental DNA to survive erosion and re-deposition</a>, which could mix the genetic signals of different time periods, necessitating a degree of caution in our interpretations. </p>
<p>Until recently, there was no evidence of mammoth survival into the mid-Holocene. But studies have now shown that mammoths survived until <a href="https://doi.org/10.1073/pnas.1604903113">5,500</a> and <a href="https://doi.org/10.1016/j.yqres.2008.03.005">4,000</a> years ago on Arctic islands.</p>
<p>Researchers at the <a href="https://globe.ku.dk/research/geogenetics/">Centre for GeoGenetics in Copenhagen</a> found evidence for the late survival of horses and mammoths in Alaska until as recently as as <a href="https://doi.org/10.1038/s41586-021-04016-x">7,900 years ago</a>. They also found evidence of mammoths surviving as recently as 3,900 years ago in Siberia, alongside <a href="https://globe.ku.dk/newslist/2021/geneticists-map-the-rhinoceros-family-tree/">woolly rhinoceros</a> to at least 9,800 years ago. </p>
<p>Steppe bison, which were thought to have disappeared and been replaced by the <a href="https://www.hww.ca/en/wildlife/mammals/north-american-bison.html">American bison</a> during the Pleistocene, have likewise been found to have survived even as recently as perhaps just <a href="https://doi.org/10.1073/pnas.1601077113">400 years ago</a>. We were able to observe <a href="https://doi.org/10.1016/j.cub.2021.12.023">the presence of distinct genetic lineages of both woolly mammoths and steppe bison</a> in the same sediment samples, which suggests that there were likely distinct populations of these animals living in the same area.</p>
<p>There is a growing body of evidence that many ice age megafauna probably survived well into recorded human history, roaming the north during the <a href="https://www.britannica.com/event/Bronze-Age">Bronze Age</a> and while builders worked on the <a href="https://www.worldhistory.org/Old_Kingdom_of_Egypt/">pyramids of Egypt</a>.</p>
<figure class="align-center ">
<img alt="illustration of a woolly rhinoceros" src="https://images.theconversation.com/files/441832/original/file-20220120-9089-elhtg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441832/original/file-20220120-9089-elhtg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441832/original/file-20220120-9089-elhtg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441832/original/file-20220120-9089-elhtg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441832/original/file-20220120-9089-elhtg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441832/original/file-20220120-9089-elhtg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441832/original/file-20220120-9089-elhtg.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">Researchers in Denmark found evidence of woolly rhinoceroses surviving in Siberia at least 9,800 years ago.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Genetic archives of our ecological past</h2>
<p>The growing sophistication of environmental DNA methods to study ancient genetic microfossils highlights just how much information is buried in sediments. </p>
<p>Permafrost is ideal for preserving ancient DNA, but as this <a href="https://www.canadiangeographic.ca/article/arctic-permafrost-thawing-heres-what-means-canadas-north-and-world">perennially frozen ground thaws and degrades with a warming Arctic</a>, so too will the genetic material preserved within, and the evolutionary mysteries they once held. </p>
<p>Advances in paleogenetics continues to push the boundaries of what was once relegated to science fiction. Who knows what undiscovered evolutionary information remains frozen in ordinary sediments, hidden in microfossils of ancient DNA?</p><img src="https://counter.theconversation.com/content/146073/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tyler J. Murchie currently receives funding from the CANA Foundation, a non-profit organization with horse rewilding initiatives.</span></em></p>
Permafrost in the Yukon is a treasure trove of ancient environmental DNA, but climate change threatens these rich historical archives.
Tyler J. Murchie, Postdoctoral fellow, Anthropology, McMaster University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/167892
2021-09-15T06:37:54Z
2021-09-15T06:37:54Z
Bringing woolly mammoths back from extinction might not be such a bad idea — ethicists explain
<figure><img src="https://images.theconversation.com/files/421270/original/file-20210915-21-fombac.jpeg?ixlib=rb-1.1.0&rect=14%2C37%2C4977%2C3458&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>US startup Colossal Biosciences has <a href="https://www.theguardian.com/science/2021/sep/13/firm-bring-back-woolly-mammoth-from-extinction">announced plans</a> to bring woolly mammoths, or animals like them, back from extinction and into the frosty landscape of the Siberian <a href="https://www.nationalgeographic.com/environment/article/tundra-biome">tundra</a>.</p>
<p>Colossal has received US$15 million in initial funds to support research conducted by <a href="https://wyss.harvard.edu/team/core-faculty/george-church/">Harvard geneticist George Church</a>, among other work. The proposed project is exciting, with laudable ambitions — but whether it is a practical strategy for conservation remains unclear.</p>
<p>Colossal proposes to use CRISPR gene editing technology to modify Asian elephant embryos (the mammoth’s closest living relative) so their genomes resemble those of woolly mammoths. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Asian elephants" src="https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/421279/original/file-20210915-26-1830agd.jpeg?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">The Asian elephant is an endangered species found across the Indian subcontinent and Southeast Asia.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-crispr-the-gene-editing-technology-that-won-the-chemistry-nobel-prize-147695">What is CRISPR, the gene editing technology that won the Chemistry Nobel prize?</a>
</strong>
</em>
</p>
<hr>
<p>These embryos could then theoretically develop into elephant-mammoth hybrids (mammophants), with the appearance and behaviour of extinct mammoths. According to Colossal, the ultimate aim is to release herds of these mammophants into the Arctic, where they will fill the ecological niche mammoths once occupied. </p>
<p>When mammoths disappeared from the Arctic some <a href="https://www.businessinsider.com.au/woolly-mammoths-arctic-island-last-to-go-extinct-2019-10">4,000 years ago</a>, shrubs overtook what was previously grassland. Mammoth-like creatures could help restore this ecosystem by trampling shrubs, knocking over trees, and fertilising grasses with their faeces. </p>
<p>Theoretically, this could help reduce climate change. If the current Siberian permafrost melts, it will release potent greenhouse gases. Compared to tundra, grassland might <a href="https://www.statnews.com/2021/09/13/woolly-mammoths-george-church-colossal-launches/">reflect more light and keep the ground cooler</a>, which Colossal hopes will prevent the permafrost from melting.</p>
<p>While the prospect of reviving extinct species has long been discussed by groups such as <a href="https://reviverestore.org/">Revive and Restore</a>, advances in genome editing have now brought such dreams close to reality. But just because we have the tools to resurrect mammoth-like creatures, does this mean we should? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Siberian tundra landscape" src="https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/421278/original/file-20210915-23-aha9vq.jpeg?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">Mammoth-like beasts with thick fur and dense fat would in theory be able to survive the harsh polar climate of the Siberian tundra.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>A cause worth considering</h2>
<p>De-extinction is a controversial field. Critics have referred to such practices as “<a href="https://www.huffpost.com/entry/extinct-species_b_3188392">playing god</a>” and accused scientists in favour of de-extinction of <a href="https://www.youtube.com/watch?v=h7vpNv_mK5I&t=767s">hubris</a>. </p>
<p>A common worry is that bringing back extinct species, whose ecological niches may no longer exist, will upset existing ecosystems. But when it comes to mammophants, this critique lacks bite. </p>
<p>Colossal says it aims to recreate the steppe ecosystem (a large, flat grassland) that flourished in Siberia until about 12,000 years ago. It has been estimated the total mass of plants and animals in Siberia’s tundra is now <a href="https://www.sciencedirect.com/science/article/pii/S0277379112003939">100-fold less than when it was a steppe</a>. </p>
<p>Simply, this ecosystem is already compromised, and it’s hard to see how reintroducing mammophants would lead to further damage. </p>
<p>Reintroducing species can transform ecosystems for the better. A well-known example is the reintroduction of wolves to Yellowstone National Park in the 1990s, which started a <a href="https://www.theguardian.com/environment/2020/jan/25/yellowstone-wolf-project-25th-anniversary">cascade of positive changes for local flora and fauna</a>. Mammophants may do the same.</p>
<p>Furthermore, climate change is one of the great moral <a href="https://theconversation.com/there-are-10-catastrophic-threats-facing-humans-right-now-and-coronavirus-is-only-one-of-them-136854">challenges of our time</a>. The melting of the Siberian permafrost is expected to accelerate climate change and exacerbate ecological disaster. </p>
<p>This is such a serious problem that even ambitious projects with a low probability of success can be ethically justified. Often our moral intuitions are clouded when considering new technologies and interventions.</p>
<p>But technologies which originally seemed scary and unnatural can slowly become accepted and valued. One tool that is sometimes used to overcome these tendencies is called the <a href="https://www.nickbostrom.com/ethics/statusquo.pdf">reversal test</a>, which was originally developed by Oxford philosophers Nick Bostrom and Toby Ord as a way to tackle <a href="https://www.behavioraleconomics.com/resources/mini-encyclopedia-of-be/status-quo-bias/">status quo bias</a>.</p>
<p>This test involves assuming the new thing already exists, and the novel proposal is to take it away. Imagine an endangered population of mammophants currently inhabits Siberia, where it plays an important role in maintaining the ecosystem and protecting the permafrost. </p>
<p>Few would argue attempts to save these mammophants are “unethical”. So if we would welcome efforts to save them in this hypothetical scenario, we should also welcome efforts to introduce them in real life.</p>
<p>So according to the reversal test, the key ethical objections to Colossal’s project should not relate to its aims, but rather to its means. </p>
<h2>The main ethical concerns</h2>
<p>Let’s look at two ethical concerns related to de-extinction. The first is that de-extinction could distract from more cost-effective efforts to protect biodiversity or mitigate climate change. The second relates to the possible moral hazards that may arise if people start believing extinction is not forever.</p>
<p><strong>1. Opportunity costs</strong></p>
<p>Some critics of de-extinction projects hold that while de-extinction may be an admirable goal, in practice it constitutes a waste of resources. Even if newly engineered mammophants contain mammoth DNA, there is no guarantee these hybrids will adopt the behaviours of ancient mammoths. </p>
<p>For instance, we inherit more than just DNA sequences from our parents. We inherit epigenetic changes, wherein the environment around us can affect <a href="https://academic.oup.com/beheco/article/24/2/311/249051">how those genes are regulated</a>. We also inherit our parents’ microbiome (colonies of gut bacteria), which plays an <a href="https://www.nature.com/articles/s41579-018-0014-3">important role in our behaviours</a>. </p>
<p>Also important are the behaviours animals learn from observing other members of their species. The first mammophants will have no such counterparts to learn from. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Rendering of woolly mammoths on field." src="https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/421272/original/file-20210915-25-ec4utj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">If mammoth-like beasts were introduced to Siberia today, they would not have parents from which to learn behaviours.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>And even if de-extinction programs are successful, they will likely <a href="https://www.nature.com/articles/s41559-016-0053">cost more</a> than saving existing species from extinction. The programs might be a poor use of resources, especially if they attract funding that could have otherwise gone to more promising projects.</p>
<p>The opportunity costs of de-extinction should be carefully scrutinised. As exciting as it may be to see herds of wild mammophants, we shouldn’t let this vision distract us from more cost-effective projects. </p>
<p>That said, we also shouldn’t rule out de-extinction technologies altogether. The costs will eventually come down. In the meantime, some highly expensive projects might be worth considering.</p>
<p><strong>2. Broader implications for conservation</strong></p>
<p>The second concern is more subtle. <a href="https://e360.yale.edu/features/the_case_against_de-extinction_its_a_fascinating_but_dumb_idea?utm_source=pocket_mylist">Some</a> <a href="https://slate.com/technology/2014/12/de-extinction-ethics-why-extinct-species-shouldnt-be-brought-back.html?utm_source=pocket_mylist">environmentalists</a> argue once de-extinction becomes possible, the need to protect species from extinction will seem less urgent. Would we still worry about preventing extinctions if we can just reverse them at a later date?</p>
<p>Personally, however, we are not convinced by these concerns. Extinction is currently irreversible, yet humans continue to <a href="https://www.popularmechanics.com/science/animals/a32743456/rapid-mass-extinction/">drive an era of mass extinction</a> that shows no sign of slowing. In other words, moving towards increasing extinctions is the status quo, and this status quo is not worth preserving.</p>
<p>Also, de-extinction is not the only conservation strategy that seeks to undo otherwise irreversible losses. For example, “rewilding” involves reintroducing locally-extinct species into an ecosystem it once inhabited. If we welcome these efforts — and we should — then we should also welcome novel strategies to restore lost species and damaged ecosystems.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/who-guidelines-on-human-genome-editing-why-countries-need-to-follow-them-164895">WHO guidelines on human genome editing: why countries need to follow them</a>
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</em>
</p>
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<img src="https://counter.theconversation.com/content/167892/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julian Koplin, via his affiliation with the Murdoch Children's Research Institute, received funding from the Victorian State Government via the Operational Infrastructure Support program.</span></em></p><p class="fine-print"><em><span>Christopher Gyngell, via his affiliation with the Murdoch Children's Research Institute, received funding from the Victorian State Government via the Operational Infrastructure Support Program</span></em></p>
While the prospect of reviving extinct species has long been discussed, advances in genome editing have now brought such dreams close to reality.
Julian Koplin, Resarch Fellow in Biomedical Ethics, Melbourne Law School and Murdoch Children's Research Institute, The University of Melbourne
Christopher Gyngell, Research Fellow in Biomedical Ethics, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/155485
2021-02-17T16:08:17Z
2021-02-17T16:08:17Z
We sequenced the oldest ever DNA, from million-year-old mammoths
<figure><img src="https://images.theconversation.com/files/384700/original/file-20210217-23-1tad8h0.jpeg?ixlib=rb-1.1.0&rect=52%2C27%2C1992%2C1122&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Current view of the steppe mammoth, an ancestor to the woolly mammoth.</span> <span class="attribution"><span class="source">Beth Zaiken/Centre for Palaeogenetics</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Most people think of mammoths as the iconic woolly species from the last Ice Age, which ended around 12,000 years ago. But mammoths originated in Africa around 5 million years ago, then spread and diversified across Eurasia and North America. </p>
<p>About a million years ago there was one known species of mammoth inhabiting Siberia, the steppe mammoth. This was thought to be the ancestor of later species such as the woolly and Columbian mammoths. But was it?</p>
<p><a href="https://dx.doi.org/10.1038/s41586-021-03224-9">In a new study</a>, we show mammoth DNA as old as 1.2 million years can be recovered from remains found in permafrost deposits. By sequencing this DNA – studying the make up of its genetic information – we found a lineage of mammoths never described before, the hybrid origin of a mammoth species, and more. </p>
<h2>Sequencing million-year-old DNA</h2>
<p>Back in 2017, we received samples from extremely old mammoth teeth, that had been frozen in time in Siberian permafrost. A few days later, our colleague Patrícia Pečnerová was heading into the lab with a clear job – to extract DNA from some of the oldest known mammoth samples. She succeeded.</p>
<p>Some weeks later, we were looking at millions of DNA sequences that undoubtedly matched the African savannah elephant genome, the model we use to assemble the jigsaw puzzle of each mammoth genome we sequence. Pečnerová built some quick phylogenetic trees – like a family tree for the evolution of mammoths – and showed them to us. It was not quite a “Eureka!” moment like in the movies, but close.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fossil-footprints-the-fascinating-story-behind-the-longest-known-prehistoric-journey-147520">Fossil footprints: the fascinating story behind the longest known prehistoric journey</a>
</strong>
</em>
</p>
<hr>
<p>It took a long time to make sure these sequences were actually very old mammoth DNA. For example, ancient DNA shows a characteristic, well known, pattern of chemical damage. While this can cause trouble for some genetic analyses, it also helps disentangle true ancient DNA from modern contaminants, which don’t show such a pattern. Our mammoth sequences did show the expected pattern.</p>
<p>The DNA sequences also had another characteristic of very old DNA – they were extremely fragmented. Instead of the longer DNA sequences found in younger, better preserved mammoth samples from the permafrost, we only had short ones. </p>
<p>This caused another problem, because shorter sequences are increasingly difficult to place in their correct position of the genome. They can also be confused with contamination. To avoid this we had to discard all the sequences below a certain length threshold, which was painful but necessary. </p>
<figure class="align-center ">
<img alt="Woolly mammoth tusk emerging from permafrost." src="https://images.theconversation.com/files/384702/original/file-20210217-17-npuw77.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/384702/original/file-20210217-17-npuw77.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/384702/original/file-20210217-17-npuw77.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/384702/original/file-20210217-17-npuw77.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/384702/original/file-20210217-17-npuw77.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/384702/original/file-20210217-17-npuw77.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/384702/original/file-20210217-17-npuw77.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Woolly mammoth tusk in Siberia.</span>
<span class="attribution"><span class="source">Love Dalén</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Lost lineages and hybrid origins</h2>
<p>We tried to put our samples in the context of all known mammoth species. Our results clearly indicated the 1.1 million-year-old specimen – which we named Adycha – was ancestral to the woolly mammoths. But placing the lineage of another sample, dating to 1.2 million years ago, which we named Krestovka, proved to be much more difficult. It sometimes seemed closely related to the Columbian mammoth, sometimes to the woolly mammoth.</p>
<p>It took several genetic analyses and hours of discussion and whiteboard drawing to finally uncover the reason for this. The Columbian mammoth had a hybrid origin – not just one ancestor lineage, but two.</p>
<p>Our results paint a picture in which roughly half of the ancestry of the Columbian mammoth could be traced to the Krestovka lineage and the other half to the woolly mammoth lineage. </p>
<p>This could finally explain a long-lasting mammoth mystery, why all Columbian mammoths sequenced so far had mitochondrial genomes – genetic information entirely inherited from an animal’s mother –closely related to those of woolly mammoths. Now, we think the Columbian mammoths likely obtained their mitochondria by reproducing with woolly mammoth females.</p>
<figure class="align-center ">
<img alt="Two of the study authors holding a mammoth tusk." src="https://images.theconversation.com/files/384764/original/file-20210217-15-rizlah.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/384764/original/file-20210217-15-rizlah.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/384764/original/file-20210217-15-rizlah.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/384764/original/file-20210217-15-rizlah.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/384764/original/file-20210217-15-rizlah.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/384764/original/file-20210217-15-rizlah.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/384764/original/file-20210217-15-rizlah.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">
<figcaption>
<span class="caption">Love Dalén and Patrícia Pečnerová with a mammoth tusk.</span>
<span class="attribution"><span class="source">Gleb Danilov</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Evolution: caught in the act</h2>
<p>If we were to ask what makes a woolly mammoth a woolly mammoth, most people would refer to their furriness. But there are also many other characteristic adaptations of the woolly mammoth to arctic environments such as increased fat deposits, higher tolerance for cold temperatures, modified circadian rhythms and more. We looked at how many of those adaptations we could find already existing more than one million years ago. Surprisingly, we found a majority of these adaptations were already present in the genome of Adycha.</p>
<p>We think this finding could have wide implications in the study of how species evolve. There’s an open question in evolutionary biology, whether the rate of adaptation is accelerated during a speciation event – when populations become separate species – or if it’s a more gradual process. </p>
<p>Our data support the latter scenario, where there is no evidence of faster natural selection acting during the origin of the woolly mammoth. And most adaptations characteristic of the woolly mammoth were already present in its ancestral species that roamed the Siberian steppe over a million years ago.</p>
<h2>Where’s the limit?</h2>
<p>Until now, the oldest DNA sequenced belonged to <a href="https://www.nature.com/articles/nature12323">a horse specimen</a> dated to between 560,000 and 780,000 years old and recovered from the permafrost deposits of Thistle Creek in the Yukon, Canada.</p>
<p>Our million-year-old mammoth samples share a crucial characteristic with the Thistle Creek horse, they were preserved in subzero permafrost deposits. Frozen at death, or soon thereafter, the degradation of the DNA molecules in these remains was slowed down for hundreds of thousands of years until we recovered and sequenced them. </p>
<p>We think permafrost preserved material holds the promise of even older DNA. However, since the oldest permafrost deposits are dated to the Early Pleistocene – around 2.6 million years ago – this may, sadly, put an upper limit on what is possible.</p><img src="https://counter.theconversation.com/content/155485/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Díez-del-Molino receives funding from the Carl Tryggers Foundation. </span></em></p><p class="fine-print"><em><span>Love Dalén receives funding from the Swedish Research Council, the research council FORMAS and Tryggers Foundation. </span></em></p>
Our results have revolutionised the previously held view of the evolution of mammoths.
David Díez-del-Molino, Postdoctoral Researcher, Centre for Palaeogenetics, Stockholm University
Love Dalén, Professor in Evolutionary Genetics, Centre for Palaeogenetics, Stockholm University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/147520
2020-10-09T10:35:35Z
2020-10-09T10:35:35Z
Fossil footprints: the fascinating story behind the longest known prehistoric journey
<figure><img src="https://images.theconversation.com/files/362656/original/file-20201009-23-b05p16.jpg?ixlib=rb-1.1.0&rect=32%2C0%2C10751%2C4381&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A prehistoric woman with a child have left behind the world's longest trackway.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Every parent knows the feeling. Your child is crying and wants to go home, you pick them up to comfort them and move faster, your arms tired with a long walk ahead – but you cannot stop now. Now add to this a slick mud surface and a range of hungry predators around you. </p>
<p>That is the story the longest trackway of fossil footprints in the world tells us. Our new discovery, <a href="https://www.sciencedirect.com/science/article/pii/S0277379120305722?dgcid=author">published in Quaternary Science Reviews</a>, comes from <a href="http://www.nps.gov/whsa">White Sands National Park</a> in New Mexico, US, and was made by an international team working in collaboration with staff from the <a href="https://www.nps.gov/index.htm">National Park Service</a>. </p>
<p>The footprints were spotted in a dried-up lakebed known as a playa, which contains literally hundreds of thousands of footprints dating from the end of the last ice age (about 11,550 years ago) to sometime before about 13,000 years ago. </p>
<p>Unlike many <a href="https://theconversation.com/our-controversial-footprint-discovery-suggests-human-like-creatures-may-have-roamed-crete-nearly-6m-years-ago-82326">other known footprint trackways</a>, this one is remarkable for its length – over at least 1.5km – and straightness. This individual did not deviate from their course. But what is even more remarkable is that they followed their own trackway home again a few hours later.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Photo showing the footprints." src="https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=287&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=287&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=287&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=361&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=361&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361670/original/file-20201005-14-1c8gub2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=361&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 section of the double trackway. Outward and homeward journeys following each other. Central Panel: Child tracks in the middle of nowhere. Left Panel: One of the tracks with little slippage.</span>
<span class="attribution"><span class="source">M Bennett, Bournemouth University.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Each track tells a story: a slip here, a stretch there to avoid a puddle. The ground was wet and slick with mud and they were walking at speed, which would have been exhausting. We estimate that they were walking at over 1.7 metres per second – a comfortable walking speed is about 1.2 to 1.5 metres per second on a flat dry surface. The tracks are quite small and were most likely made by a woman, or possibly an adolescent male. </p>
<h2>Mysterious journey</h2>
<p>At several places on the outward journey there are a series of small child tracks, made as the carrier set a child down perhaps to adjust them from hip to hip, or for a moment of rest. Judging by the size of the child tracks, they were made by a toddler maybe around two years old or slightly younger. The child was carried outward, but not on the return. </p>
<p>We can see the evidence of the carry in the shape of the tracks. They are broader due to the load, more varied in morphology often with a characteristic “banana shape” – something that is caused by outward rotation of the foot.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=492&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=492&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=492&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=619&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=619&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361672/original/file-20201005-24-outyqb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=619&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Colour depth rendered 3D scans of some of the footprints. Note the distinctive curved shape which seems to be a feature of load carrying.</span>
<span class="attribution"><span class="source">Bournemouth University.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The tracks of the homeward journey are less varied in shape and have a narrower form. We might even go as far as to tentatively suggest that the surface had probably dried a little between the two journeys. </p>
<h2>Dangerous predators</h2>
<p>The playa was home to many extinct ice age animals, perhaps hunted to extinction by humans, perhaps not. Tracks of these animals helped determine the age of the trackway. </p>
<p>We found the tracks of mammoths, giant sloths, sabre-toothed cats, dire wolves, bison and camels. We have <a href="https://theconversation.com/how-to-hunt-a-giant-%20sloth-according-to-ancient-human-footprints-95344">produced footprint evidence</a> in the past of how these animals may have been hunted. What’s more, research yet to be published tells of children playing in puddles formed in giant sloth tracks, jumping between mammoth tracks and of hunting and butchery.</p>
<p>Between the outward and return journeys, a sloth and a mammoth crossed the outward trackway. The footprints of the return journey in turn cross those animal tracks. </p>
<p>The sloth tracks show awareness of the human passage. As the animal approached the trackway, it appears to have reared-up on its hind legs to catch the scent – pausing by turning and trampling the human tracks before dropping to all fours and making off. It was aware of the danger. </p>
<p>In contrast, the mammoth tracks, at one site made by a large bull, cross the human trackway without deviation, most likely not having noticed the humans.</p>
<p>The trackway tells a remarkable story. What was this individual doing alone and with a child out on the playa, moving with haste? Clearly it speaks to social organisation, they knew their destination and were assured of a friendly reception. Was the child sick? Or was it being returned to its mother? Did a rainstorm quickly come in catching a mother and child off guard? We have no way of knowing and it is easy to give way to speculation for which we have little evidence. </p>
<p>What we can say is that the woman is likely to have been uncomfortable on that hostile landscape, but was prepared to make the journey anyway. So next time you are rushing around in the supermarket with a tired child in your arms, remember that even prehistoric parents shared these emotions.</p><img src="https://counter.theconversation.com/content/147520/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Robert Bennett receives funding from UK Natural Environment Research Council. </span></em></p><p class="fine-print"><em><span>Sally Christine Reynolds 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>
Some 13,000 years ago, an adult carrying in a child walked 1.5km in mud at great speed in the presence of hungry predators.
Matthew Robert Bennett, Professor of Environmental and Geographical Sciences, Bournemouth University
Sally Christine Reynolds, Principal Academic in Hominin Palaeoecology, Bournemouth University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/138142
2020-09-07T09:23:47Z
2020-09-07T09:23:47Z
Mammoth task: the Russian family on a resurrection quest to tackle the climate crisis
<figure><img src="https://images.theconversation.com/files/354337/original/file-20200824-22-paj4at.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Zimovs take some permafrost depth readings.</span> <span class="attribution"><span class="source">© Charlotte Wrigley</span>, <span class="license">Author provided</span></span></figcaption></figure><p>On the banks of the River Kolyma, deep into the Arctic circle in north-east Siberia, lies a gently rusting Soviet-era tank. It doesn’t look out of place here. After all, just down the river is the hull of a half-sunken ship and the remains of an Aeroflot aeroplane fuselage that met an unfortunate end. </p>
<p>The tank isn’t working at the moment – it’s hard to find parts – but until recently, it was driven by a bearded Russian wearing a beret, a cigarette clamped permanently between his jaws, taking a sort of macabre delight in destroying trees and churning up soil.</p>
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<img alt="A picture of a tank." src="https://images.theconversation.com/files/353408/original/file-20200818-24-c3slq9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353408/original/file-20200818-24-c3slq9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353408/original/file-20200818-24-c3slq9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353408/original/file-20200818-24-c3slq9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353408/original/file-20200818-24-c3slq9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353408/original/file-20200818-24-c3slq9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353408/original/file-20200818-24-c3slq9.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">
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<span class="caption">The obvious replacement for a mammoth.</span>
<span class="attribution"><span class="source">© Charlotte Wrigley</span>, <span class="license">Author provided</span></span>
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<p>This is Sergey Zimov who, together with his son Nikita, is carrying out an experiment on this scrubby patch of Arctic tundra: they want to restore the prehistoric “mammoth steppe” ecosystem and see if it proves their hypothesis that a grassland grazed by large herbivores has an effect on slowing down – or even reversing – the thawing permafrost.</p>
<p>Currently the landscape is mostly larch forest with very low biodiversity. There are no animals, save for the odd moose and millions of mosquitoes. Meanwhile, Arctic temperatures are increasing <a href="https://www.npr.org/2014/12/18/371438087/arctic-is-warming-twice-as-fast-as-world-average">twice as quickly</a> as those in the rest of the planet, and the permafrost that covers 65% of Russia <a href="https://www.nature.com/articles/s41558-019-0592-8?fbclid=IwAR1GLrQiGpH_25nIjqH_ih4zp24YpbtvhF2nec3bUK8e9Hi8zYaD151Irws">is thawing</a>. Fast. Many of the buildings in the town of Chersky – where the Zimov experiment is based – sport deep cracks (some have collapsed altogether), roads are buckled and the ground is humped and hollowed.</p>
<p>The clue to what counts as permafrost is in the name – permanently frozen ground. As with anything frozen, it is liable to thaw if temperatures get too hot. That is precisely what is happening all across the Arctic. </p>
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<img alt="Buildings sit to either side of a road under a blue sky." src="https://images.theconversation.com/files/353409/original/file-20200818-16-5ar3hs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353409/original/file-20200818-16-5ar3hs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353409/original/file-20200818-16-5ar3hs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353409/original/file-20200818-16-5ar3hs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353409/original/file-20200818-16-5ar3hs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353409/original/file-20200818-16-5ar3hs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353409/original/file-20200818-16-5ar3hs.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">
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<span class="caption">The town of Chersky.</span>
<span class="attribution"><span class="source">© Charlotte Wrigley</span>, <span class="license">Author provided</span></span>
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<p>Permafrost is difficult to define. It covers almost a quarter of the Northern Hemisphere and sequesters <a href="https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle">double</a> the carbon found in the atmosphere today. When frozen, the microbes that feed on the organic material found in permafrost are “asleep”. When it thaws, they wake up and the anaerobic respiration produced releases greenhouse gases. </p>
<p>Officially, it’s soil that has been frozen for two years or more, with an “active layer” that thaws seasonally. But thanks to global warming, permafrost has been thawing with increasing magnitude, with all sorts of disruptive effects. A process called a “<a href="https://epic.awi.de/id/eprint/31461/">thermokarst megaslump</a>” has opened up huge holes across the tundra and the bodies of mammoths are being found with <a href="https://www.nytimes.com/2019/08/04/world/europe/russia-siberia-yakutia-permafrost-global-warming.html">greater frequency</a>, their flesh decomposing in the Arctic sun. Strange things are awakening. A couple of years ago, a team of Russian scientists reportedly found <a href="https://www.smithsonianmag.com/smart-news/ancient-roundworms-allegedly-resurrected-russian-permafrost-180969782/">30,000-year-old worms</a> in the permafrost which, upon being warmed up gently in a Moscow laboratory, began to wriggle around. </p>
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<img alt="" src="https://images.theconversation.com/files/351063/original/file-20200804-24-g44qjh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/351063/original/file-20200804-24-g44qjh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=347&fit=crop&dpr=1 600w, https://images.theconversation.com/files/351063/original/file-20200804-24-g44qjh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=347&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/351063/original/file-20200804-24-g44qjh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=347&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/351063/original/file-20200804-24-g44qjh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=436&fit=crop&dpr=1 754w, https://images.theconversation.com/files/351063/original/file-20200804-24-g44qjh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=436&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/351063/original/file-20200804-24-g44qjh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=436&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">Global map of permafrost regions.</span>
<span class="attribution"><span class="source">Hugo Ahlenius</span></span>
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<p>Almost ironically, the mammoths exposed by the thawing of permafrost are what sparked Sergey Zimov’s hypothesis: that large herbivores are necessary to maintain the integrity of permafrost. The Zimovs use their tank to mimic the tread and destructiveness of the woolly mammoth in a 144km² fenced off area they call “<a href="https://pleistocenepark.ru/">Pleistocene Park</a>”. </p>
<p>Recreating the mammoth’s former ecosystem might seem like an impossible task given the creature has been extinct for 4,000 years, but for the Zimovs this is a minor detail. They are concerned with ecological processes – the web of connection that produces a functioning ecosystem. The tank will do just fine as a mammoth-stand in, destroying trees and stimulating grass growth in its wake. </p>
<p>There are animals in the park that play a similar role. Yakutian horses and reindeer have been purchased from local indigenous herders, and other creatures that haven’t lived in the region for a long time (yak, sheep, Kalmykian cow, musk ox, bison) have come from much further afield. There are around 120 animals in total, although deaths and births happen with regularity. Last summer, Nikita Zimov undertook a perilous journey by truck to transport 12 baby bison all the way from Denmark. The roads are dreadful for most of Northern Siberia, and then they disappear completely. Travelling by barge along the Kolyma is the only way in. </p>
<p>A few seasons before that, an expedition to Wrangel Island in the Arctic Ocean to find musk oxen almost ended in disaster after their boat hit a storm. The discovery on return that all the oxen were males was a particularly frustrating one. The animals in the park roam where they please, encouraged to breed and forage so their behaviours <a href="https://www.journals.uchicago.edu/doi/abs/10.1086/285824">have an effect</a> on the permafrost: trampling compacts ground and keeps it frozen, while grassland reflects solar radiation.</p>
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<img alt="" src="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.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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<p><strong><em>This article is part of Conversation Insights</em></strong>
<br><em>The Insights team generates <a href="https://theconversation.com/uk/topics/insights-series-71218">long-form journalism</a> derived from interdisciplinary research. The team is working with academics from different backgrounds who have been engaged in projects aimed at tackling societal and scientific challenges.</em> </p>
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<p>Even though the tank remains out of commission, the Zimovs are hoping that soon they won’t need it at all. They’re hoping that one day a mammoth will return to the Arctic.</p>
<h2>Resurrecting the dead</h2>
<p>Sometime in the early 2000s, rumblings began in the scientific community of a new form of conservation that would potentially fix a growing problem. What if, instead of fighting what seemed to be an <a href="https://www.theguardian.com/environment/2017/jul/10/earths-sixth-mass-extinction-event-already-underway-scientists-warn">increasingly losing battle</a> against extinction, you could potentially resurrect an extinct creature through cloning methods? </p>
<p>Still reeling from the implications of Dolly the sheep in 1997, in 2003 a team of scientists in Zaragoza, Spain, managed to <a href="https://www.theatlantic.com/technology/archive/2013/03/the-10-minutes-when-scientists-brought-a-species-back-from-extinction/274118/">successfully produce</a> a clone of the extinct Pyrenean ibex, having previously collected genetic material from the last remaining individual of the species. Although the cloned calf only lived for ten minutes, the genie was out of the bottle: extinction didn’t have to be forever. </p>
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Read more:
<a href="https://theconversation.com/produce-mammoth-stem-cells-says-creator-of-dolly-the-sheep-16335">Produce mammoth stem cells, says creator of Dolly the sheep</a>
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<p>Advances in genetic technology saw the arrival of CRISPR, a type of gene editing software that allowed for swift and cheap splicing of genomes. Now it didn’t matter if you didn’t have a viable cell for cloning – you could simply create a complete genome in a laboratory. This is what happened with <a href="https://reviverestore.org/projects/woolly-mammoth/progress/">the mammoth</a>, whose genome was sequenced in 2015, becoming the first extinct creature to be catalogued. </p>
<p>While preserved mammoth bodies are common finds in Siberia, their flesh prevented from decomposition by permafrost, living cells begin to degrade at the point of death so a certain amount of cell degradation is inevitable. But by using CRISPR, a scientist is able to plug, say, the genome of an Asian elephant with the genes that make the physical traits of a mammoth (cold adapted blood, thick hair, small ears). Theoretically, if that genome was implanted into an egg and then fertilised, the Asian elephant in question would give birth to a mammoth, albeit one that is genetically a hybrid. </p>
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<p>De-extincting the mammoth in the future is a possibility, but the follow up question must surely be: what does one do with such a creature? Enter the Pleistocene Park. The vast expanse of tundra and cold temperatures, not to mention the ready-made connotations with a similar de-extinction “project”, Jurassic Park, mean it is the obvious place for any newly “resurrected” (hybridised, to be exact) mammoth to go.</p>
<p>All this talk of restoration, rebirth and resurrection raises further questions: one of them being the ethical implications of “playing God”. But the other, larger question regards the role of humanity on the planet. We are now <a href="https://www.nature.com/articles/d41586-019-01641-5">unofficially</a> living in the Anthropocene – a new epoch that designates humans as top geological agents, leaving our mark in the rock and influencing just about every planetary process. Most of our actions are not positive ones, evidenced by the tide of environmental destruction, global warming and explosive levels of extinction left in our wake. </p>
<p>Would resurrecting the mammoth be a way for humans to right past wrongs, or would it be an extension of the power and control we wield over a ravaged planet?</p>
<h2>‘We are as gods’</h2>
<p>I visited the Pleistocene Park in the summer of 2018 to attempt to answer this question. The mammoth is a bit of a thorny conversation topic to the Zimovs. Yes, Sergey Zimov strides around the tundra wearing a t-shirt sporting a stylised cartoon of the massive hairy elephant, but his son is quick to shoot me down when I ask about their level of involvement in de-extinction. </p>
<p>“You have a lot of people believing in God,” he says. “And they don’t like this mammoth return. So I try and use it to bring attention to the park, but I don’t want any of the criticism!” But the relationship between de-extinction scientists and the park is difficult to ignore. A few weeks after I leave the park, the Zimovs are visited by the geneticist <a href="https://wyss.harvard.edu/team/core-faculty/george-church/">George Church</a>, probably the biggest proponent of mammoth de-extinction, and <a href="http://sb.longnow.org/SB_homepage/Home.html">Stewart Brand</a>, lifelong environmentalist and now supporter of what is termed a “good Anthropocene” (the idea that humans should use their power to benevolently steward the planet). “We are as gods,” Brand <a href="https://www.edge.org/conversation/stewart_brand-we-are-as-gods-and-have-to-get-good-at-it#:%7E:text=Stewart%20Brand%20Talks%20About%20His%20Ecopragmatist%20Manifesto&text=Forty%20years%20ago%2C%20I%20could,to%20get%20good%20at%20it">famously quipped</a>: “And we have to get good at it.” </p>
<p>I’m sceptical of this viewpoint. The Anthropocene concept is a <a href="https://theconversation.com/anthropocene-doesnt-exist-and-species-of-the-future-will-not-recognise-it-111762">flattening one</a>: it categorises all humans as the same, separated from nature, wreaking havoc on a lifeless Earth. It distributes blame equally, rather than directed towards the worst polluters. It ignores the uneven and ongoing effects of climate change on different parts of the globe. Planetary stewardship – no matter how benevolent – reinforces this idea. It suggests things can, and should, be controlled.</p>
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<img alt="Brown bracken hides a figure in front of a river." src="https://images.theconversation.com/files/353411/original/file-20200818-20-wgtgkp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353411/original/file-20200818-20-wgtgkp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353411/original/file-20200818-20-wgtgkp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353411/original/file-20200818-20-wgtgkp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353411/original/file-20200818-20-wgtgkp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353411/original/file-20200818-20-wgtgkp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353411/original/file-20200818-20-wgtgkp.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">
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<span class="caption">Sergey Zimov camouflaged on the tundra.</span>
<span class="attribution"><span class="source">© Charlotte Wrigley</span>, <span class="license">Author provided</span></span>
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<p>But I don’t see much evidence of this control during my time at the park. The first day I’m taken there (it’s a 30 minute boat ride away from the science station that houses visitors) Nikita Zimov is informed by his rangers that the herd of musk oxen hasn’t been seen for days so he heads into the undergrowth to find the animals. I’m left alone, surrounded by flooded plains, no animals to be seen save for a blind yak. </p>
<p>A few days later, the permafrost tunnel floods. A sort of underground laboratory dug to house permafrost cores, scientific equipment and frozen fish, it was supposedly placed at a high enough level that the annual floodwaters of the Kolyma would never reach the entrance - until they did. We spend a day pumping the water out and dislodging the items that had stuck fast to the frozen ceiling. A little way down the river, the expensive scientific equipment owned by a well-funded contingent of German permafrost scientists is submerged under water. </p>
<p>Meanwhile, the Zimovs are furious about the 12 baby bison they have purchased from an Alaskan herder, still stuck in their pen. They’re unable to find a pilot willing to fly them over in the creaky, old DC-4 plane they have found. Everything that seemingly can go wrong, does go wrong. The Pleistocene Park is showing encouraging signs of becoming a grassland ecosystem, and <a href="https://www.nature.com/articles/s41598-020-60938-y?sf232308455=1">initial tests</a> show the permafrost is thawing less within the park’s boundaries. </p>
<p>But on the summer solstice (a swelteringly hot June day in the Arctic) we take a drill and some thaw depth probes to do some readings outside of the park, and the prognosis for the permafrost is not good. “We are fighting global warming,” Nikita Zimov says. “But global warming is fighting back.”</p>
<h2>Tusk hunts</h2>
<p>When permafrost makes the news, it’s never good. In early June, a fuel tank at the Norilsk power plant in Siberia <a href="https://www.bbc.co.uk/news/world-europe-52977740">collapsed</a> because of thawing permafrost and 17,500 tonnes of diesel spilled into the river. A lot of people live and work on top of permafrost in Russia, and at the time of the Soviet Union, thousands of people were lured to the Arctic on the promise of highly paid jobs and cheap houses as part of a plan to “master the North”. Now the Soviet Union is long gone, along with all the perks, and thawing permafrost is making Arctic life very difficult. </p>
<p>A sort of black-market industry has emerged, with groups of men heading out onto the tundra for months at a time to look for mammoth bodies that thawing permafrost has exposed. <a href="https://www.nationalgeographic.com/magazine/2013/04/tracking-mammoths1/">They’re after the tusks</a> that can be sold for a hefty profit to China, by far the world’s top market for ivory goods. These tusk hunts are often dangerous, with the men using illegal high-powered water cannons to blast holes and tunnels in permafrost, hundreds of miles away from towns or hospitals. Those who find a tusk have struck white gold, but those that don’t (most of them) will lose money. </p>
<p>There’s another tension too. To many Siberian indigenous groups, the mammoth is a sacred beast and mustn’t be disturbed – to do so could mean death. Tusk hunters face an often-agonising decision: to betray their belief system or to feed their family.</p>
<p>I became aware of an uneasy relationship between tusk hunters and scientists when I visited the Mammoth Museum in Yakutsk, where I spent the winter in 2018. Yakutsk is the world’s coldest and largest city built on permafrost, and it has no roads in or out – in the summer you take the plane, in the winter the frozen rivers become ice roads and a thriving trucking network ferries supplies to and from the Arctic towns.</p>
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<img alt="A bridge, buildings and frozen plains." src="https://images.theconversation.com/files/353412/original/file-20200818-24-15p1z30.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353412/original/file-20200818-24-15p1z30.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353412/original/file-20200818-24-15p1z30.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353412/original/file-20200818-24-15p1z30.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353412/original/file-20200818-24-15p1z30.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353412/original/file-20200818-24-15p1z30.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353412/original/file-20200818-24-15p1z30.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">
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<span class="caption">The city of Yakutsk in winter.</span>
<span class="attribution"><span class="source">© Charlotte Wrigley</span>, <span class="license">Author provided</span></span>
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<p>The Mammoth Museum and the Melnikov Permafrost Institute are institutions dedicated to understanding permafrost and tundra flora and fauna. This includes the mammoth. Since the collapse of the Soviet Union, the funding for these institutions has dried up. The scientists at the permafrost institute can only wait for international researchers with big grants to show up. </p>
<p>The museum has struck up an awkward partnership with a biotechnology company in Seoul, South Korea. Sooam Biotech is known for <a href="https://www.vanityfair.com/style/2018/08/dog-cloning-animal-sooam-hwang">cloning pets</a> (most famously, Barbara Streisand’s dog) and has made no secret of its desire to clone a mammoth. The Mammoth Museum is informed of any mammoth finds by tusk hunters and Sooam Biotech is offered first dibs on collecting genetic material from the body. In exchange, Sooam Biotech has financed a state-of-the-art laboratory and equipment for the museum.</p>
<p>Meanwhile, the Yakutian government has recently passed <a href="https://phys.org/news/2018-12-siberian-region-permafrost-planet.html">a law that protects permafrost</a>, enshrining the rights of Yakuts to live on top of solid ground. This law is mostly symbolic. Permafrost thaw is a result of global warming, yet it is Arctic Siberia that bears the brunt.</p>
<p>These smaller, messier permafrost interactions say something important. The Pleistocene Park and the designs of scientists wanting to resurrect the mammoth work very much within a global narrative. The <a href="https://www.kickstarter.com/projects/907484977/pleistocene-park-an-ice-age-ecosystem-to-save-the">promotional material</a> for the park involve references to “the world’s best plan” and “saving the world”. Similarly to the way the Anthropocene concept flattens humanity, constructing the Earth on a purely global scale produces a potential future catastrophe that hasn’t happened yet. Think about any Hollywood disaster movie – we must do something to prevent it.</p>
<p>Curating apocalypse in this way means the more local catastrophic events become seen as harbingers of a threat to come, rather than catastrophes in their own right. Permafrost makes the news as a “<a href="https://eos.org/articles/the-ticking-time-bomb-of-arctic-permafrost#:%7E:text=An%20Arctic%20ecosystem%20is%20in,than%20a%20decade%20to%20recover.">ticking time bomb</a>”, something that will blow up unless we do something about it. Yet the people who live in the Arctic, particularly indigenous groups and fragile communities like Chersky, are already dealing with an apocalypse and have been for some time. </p>
<p>The unpredictability of permafrost – now very much impermanent – challenges those proponents of a good Anthropocene who believe we can control the planet.</p>
<h2>Putting life on ice</h2>
<p>Freezing, being frozen, staying frozen – they all suggest a period of stasis, of suspension. Permafrost itself indicates permanence, but that can no longer be said to be true. What to do, when the planet is warming and the Arctic is warming even faster? Build freezers, that’s what. </p>
<p>Cryobanks have emerged in the past decade, often attached to museums, as a response to the rapid rise in species extinction. They offer a way to put “life on ice”, stored safely away until something can be done, be that captive breeding or de-extinction. Many of these projects have eschatological overtones – the <a href="https://www.smh.com.au/technology/the-lazarus-project-scientists-quest-for-deextinction-20150417-1mng6g.html">Lazarus Project</a>, <a href="https://www.frozenark.org/">The Frozen Ark</a> – and suggest that control can somehow be regained by turning the temperature down. </p>
<figure class="align-center ">
<img alt="A tray of frozen samples." src="https://images.theconversation.com/files/353413/original/file-20200818-14-1l9d8v4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353413/original/file-20200818-14-1l9d8v4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353413/original/file-20200818-14-1l9d8v4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353413/original/file-20200818-14-1l9d8v4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353413/original/file-20200818-14-1l9d8v4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353413/original/file-20200818-14-1l9d8v4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353413/original/file-20200818-14-1l9d8v4.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">Frozen samples at the London Natural History Museum s cryobank.</span>
<span class="attribution"><span class="source">© Charlotte Wrigley</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The 42,000-year-old horse lying in Yakutsk’s Mammoth Museum is dead. I can smell it. Its body had been found a few months earlier in a permafrost bank, and had been frozen in the museum’s freezer ever since. The horse has been so well preserved, it looks like it’s merely sleeping. A delegation from the pet cloning company Sooam Biotech is visiting Yakutsk to take samples, and I’ve been invited along to view the autopsy. </p>
<p>The head of the delegation, and CEO of the company, is Hwang Woo-Suk – a once disgraced South Korean veterinary scientist who made <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892198/">headlines in 2005</a> when he claimed he had cloned human cells. He hadn’t, and went from the pride of South Korea to a laughing stock overnight while claiming he had been deceived by a former colleague in the process. A few years later he began showing up in Yakutsk looking for mammoths and other prehistoric creatures. His pet cloning company makes him rich, but cloning a mammoth would bring global fame again.</p>
<figure class="align-center ">
<img alt="People in white coats stand around a horse carcass." src="https://images.theconversation.com/files/353414/original/file-20200818-14-1q5qka2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353414/original/file-20200818-14-1q5qka2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353414/original/file-20200818-14-1q5qka2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353414/original/file-20200818-14-1q5qka2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353414/original/file-20200818-14-1q5qka2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353414/original/file-20200818-14-1q5qka2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353414/original/file-20200818-14-1q5qka2.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">Ancient horse autopsy at the Mammoth Museum.</span>
<span class="attribution"><span class="source">© Charlotte Wrigley</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The Anthropocene may be the time of the human, but really it is the time of certain humans, or certain actions. Actions have consequences. The warming of the Arctic and the thawing of permafrost is but one of these consequences. The reaction to this, to attempt to regain control of planetary processes, whether this be through resurrecting the mammoth or restoring its habitat, is indicative of a commitment to a good Anthropocene that aims to continue human dominance on the Earth. </p>
<p>Having lived on top of permafrost, felt my feet sink into the mushy ground and rolled a ball of it between my fingers like putty, I remain doubtful any of this will work. What impact the Pleistocene Park may have on the permafrost around it is negated thousands of miles away by yet another thermokarst megaslump or another Arctic wildfire. While Nikita Zimov is philosophical about this, saying “it’s better to walk rather than to sit and wait for death”, it’s difficult to imagine the park ever reaching a point where it can mitigate permafrost thaw across the world. The mammoth, should it ever be resurrected, would surely exist as a curio rather than a thriving species, a monument to the hubris of playing God.</p>
<p>Those advocating a good Anthropocene mean well, but a much deeper state change is needed. The continuous layer of permafrost in Arctic Siberia is showing signs of <a href="https://www.nationalgeographic.co.uk/environment/2018/08/exclusive-some-arctic-ground-no-longer-freezing-even-winter">becoming discontinuous</a> through thaw. Discontinuity, I think, must also be our path. We need to halt and refuse the destructive practices that have underpinned the last century and beyond if there’s to be any hope of doing better in the future. </p>
<p>Discontinuity isn’t just a state of being, it is also a state of mind. The warming of the Arctic and the thawing of permafrost are huge concerns, yes, but attempts to force control of an increasingly out of control situation might well produce terrible gods rather than benevolent ones. Resurrecting mammoths – playing god – speaks to a doubling down of the mastery implied by the Anthropocene moniker. </p>
<p>Discontinuity, conversely, allows for the creativity in thinking of futures that relinquish destructive human dominance. The Pleistocene Park may be one of these futures, or it may not be. The point is, by becoming discontinuous, we become attuned to a radical openness that allows for thinking differently – ethically, collectively, progressively – about our role as humans on a discontinuous Earth. </p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=112&fit=crop&dpr=1 600w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=112&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=112&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=140&fit=crop&dpr=1 754w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=140&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=140&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>For you: more from our <a href="https://theconversation.com/uk/topics/insights-series-71218?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=InsightsUK">Insights series</a>:</em></p>
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<li><p><em><a href="https://theconversation.com/searching-for-misha-the-life-and-tragedies-of-the-worlds-most-famous-polar-bear-137344?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=InsightsUK">Searching for Misha: the life and tragedies of the world’s most famous polar bear</a></em></p></li>
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<p class="fine-print"><em><span>Charlotte Wrigley received funding from the Economic and Social Research Council (ESRC) for this project.</span></em></p>
The Zimovs want to restore the prehistoric ‘mammoth steppe’ ecosystem and see if it slows down – or even reverses – melting permafrost.
Charlotte Wrigley, PhD Candidate, Queen Mary University of London
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/132627
2020-04-29T15:48:10Z
2020-04-29T15:48:10Z
How bison, moose and caribou stepped in to do the cleaning work of extinct mammoths
<figure><img src="https://images.theconversation.com/files/330714/original/file-20200427-145560-nibdjc.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3777%2C2050&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Unlike mammoths, bison survived in Alaska at the end of the last ice age.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/QvCcqTHlLCE">Hans Veth/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The extinction of one species can create ripples that transform an ecosystem. That’s particularly true for so-called “ecosystem engineer” species. Beavers are one example – they dam rivers, creating ponds and channels that <a href="https://theconversation.com/beavers-are-set-to-recolonise-the-uk-heres-how-people-and-the-environment-could-benefit-132116">offer refuge for spawning fish and small mammals</a>.</p>
<p>Large herbivores such as <a href="http://thinkelephants.blogspot.com/2012/10/elephants-ecosystems-engineers.html">elephants, horses and reindeer</a> are engineers too – they break down shrubs and trees to create open grasslands, habitats that benefit a wealth of species.</p>
<p>We know that their ancestors – such as the woolly mammoth – shaped the world around them in a similar way, but what happened to those ancient ecosystems when they died out?</p>
<p>Our <a href="https://www.cambridge.org/core/journals/quaternary-research/article/tracking-latequaternary-extinctions-in-interior-alaska-using-megaherbivore-bone-remains-and-dung-fungal-spores/BD3C13789FBB262EDCA8432CBB47067E">new research published in the journal Quaternary Research</a> studied the extinction of mammoth, wild horse and saiga antelope towards the end of the last ice age in interior Alaska, analysing fossilised <a href="https://methodsblog.com/2016/07/19/european-bison/">dung fungal spores</a> recovered from the bottom of lakes and <a href="https://www.nps.gov/articles/aps-17-1-4.htm">ancient bones recovered from buried</a> sediments.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-what-effect-did-the-asteroid-that-wiped-out-the-dinosaurs-have-on-plants-and-trees-132386">Curious Kids: What effect did the asteroid that wiped out the dinosaurs have on plants and trees?</a>
</strong>
</em>
</p>
<hr>
<p>We wanted to know how ancient ecosystems responded to these species dying out so that it might teach us more about mass extinctions today. What we discovered could offer hope for modern ecosystems facing biodiversity loss.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/330716/original/file-20200427-145536-v86bx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/330716/original/file-20200427-145536-v86bx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=346&fit=crop&dpr=1 600w, https://images.theconversation.com/files/330716/original/file-20200427-145536-v86bx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=346&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/330716/original/file-20200427-145536-v86bx3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=346&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/330716/original/file-20200427-145536-v86bx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/330716/original/file-20200427-145536-v86bx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/330716/original/file-20200427-145536-v86bx3.jpg?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">A museum replica of a woolly mammoth. Mammoths helped maintain open habitats by grazing herbs, trees and bushes.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dvur-kralove-czech-republic-08132013-big-1024532596">Noska Photo/Shutterstock</a></span>
</figcaption>
</figure>
<h2>How ancient ecosystems coped with extinctions</h2>
<p>The late-Quaternary extinctions occurred towards the end of the last ice age. In North America, they saw the loss of large herbivores and carnivores, whose relatives still roam other continents as elephants, wild horses and tigers. This was a period of rapid climate change and growing pressure from humans.</p>
<p><a href="https://www.researchgate.net/publication/269820457_Late_Quaternary_megafaunal_extinctions_on_the_continents_A_short_review">Previous research showed that 69% of large mammals</a> were lost from North America around this time. Similar losses were seen on other continents, <a href="https://www.discovermagazine.com/planet-earth/dung-fungus-reveal-that-humans-not-climate-change-killed-australias-giant-beasts">including Australia</a>. The diversity of mammal species shrank, but more significant was the <a href="https://doc.rero.ch/record/210391/files/PAL_E4398.pdf">crash in numbers of all mammals</a>, including species that survived the extinction event.</p>
<p><a href="https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.12576">Previous research</a> showed that elsewhere in the Americas, the loss of ecosystem engineers like the woolly mammoth led to an explosion in plant growth, as trees and shrubs were no longer grazed and browsed so intensively. In turn, there were larger and more frequent wildfires.</p>
<p>But in Alaska, our results revealed that other species of wild herbivores, including bison, moose, caribou and musk ox, increased in abundance, making up for the loss of mammoths, saiga antelopes and wild horses.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/330718/original/file-20200427-145499-105esni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/330718/original/file-20200427-145499-105esni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=509&fit=crop&dpr=1 600w, https://images.theconversation.com/files/330718/original/file-20200427-145499-105esni.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=509&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/330718/original/file-20200427-145499-105esni.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=509&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/330718/original/file-20200427-145499-105esni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=639&fit=crop&dpr=1 754w, https://images.theconversation.com/files/330718/original/file-20200427-145499-105esni.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=639&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/330718/original/file-20200427-145499-105esni.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=639&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Saiga antelopes used to roam North America, but they are now only found in scattered pockets of Asia.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Saiga_antelope#/media/File:Saiga_antelope_at_the_Stepnoi_Sanctuary.jpg">Andrey Giljov/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>This suggests that as extinctions occurred, other large herbivores were able to fill the gap, partially taking over the lost role of ecosystem engineer. This insight from 13,000 years ago could offer hope for modern conservationists. Substituting an extinct ecosystem engineer with a similar species still living today may work to revive lost ecological processes.</p>
<p>Reintroducing large herbivores in this way is often referred to as “<a href="https://www.esf.edu/efb/parry/Invert_Cons_14_Readings/Seddon_etal_2014.pdf">rewilding</a>”. Today’s landscapes on most continents are <a href="https://www.chrispackham.co.uk/news/what-is-rewilding">empty of large vertebrate animals</a>, largely because of the late Quaternary extinctions we studied. <a href="https://www.researchgate.net/publication/257973653_Rewilding_North_America">One of the key arguments</a> behind rewilding is that bringing some of those species back to landscapes could boost biodiversity more broadly and create more diverse, resilient ecosystems.</p>
<p>But without resurrecting the woolly mammoth, our research indicates it may be possible to bring back some of the ecosystem engineering benefits of extinct species by reintroducing their living relatives or substitute species, ultimately helping surviving plants and animals to thrive.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/could-resurrecting-mammoths-help-stop-arctic-emissions-95956">Could resurrecting mammoths help stop Arctic emissions?</a>
</strong>
</em>
</p>
<hr>
<p>Our work in Alaska shows that the consequences of engineer extinctions are not always overwhelmingly negative. Studying this rare instance when ecosystems coped better with extinctions can help us design more effective conservation measures for megaherbivores today. </p>
<p>A good example of creative thinking in conservation can be found in Columbia. Here, pet hippos that escaped from Pablo Escobar’s private collection have multiplied in the wild and now appear to be recreating processes that were <a href="https://www.theguardian.com/environment/2020/mar/24/pablo-escobars-cocaine-hippos-show-how-invasive-species-can-restore-a-lost-world-aoe">lost thousands of years ago</a> when native megaherbivores died out. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/330721/original/file-20200427-145499-1a33zx6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/330721/original/file-20200427-145499-1a33zx6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/330721/original/file-20200427-145499-1a33zx6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/330721/original/file-20200427-145499-1a33zx6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/330721/original/file-20200427-145499-1a33zx6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/330721/original/file-20200427-145499-1a33zx6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/330721/original/file-20200427-145499-1a33zx6.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">These hippos are technically invasive species in Colombia and are wild descendants of Pablo Escobar’s pets.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hippopotamus-colombia-1351698167">Perla Sofia/Shutterstock</a></span>
</figcaption>
</figure>
<p>This includes the creation of well trodden hippo paths between wetlands and feeding areas on firmer ground, which help deepen water channels, disperse seeds and fertilise wetlands. Over 13,000 years ago, these processes would have been carried out by the now extinct <a href="https://prehistoric-fauna.com/Macrauchenia-patagonica">giant llama</a>, and semi-aquatic <a href="https://dcpaleo.org/notoungulata/">notoungulata</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/330738/original/file-20200427-145544-1ud4ur2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/330738/original/file-20200427-145544-1ud4ur2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=358&fit=crop&dpr=1 600w, https://images.theconversation.com/files/330738/original/file-20200427-145544-1ud4ur2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=358&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/330738/original/file-20200427-145544-1ud4ur2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=358&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/330738/original/file-20200427-145544-1ud4ur2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=450&fit=crop&dpr=1 754w, https://images.theconversation.com/files/330738/original/file-20200427-145544-1ud4ur2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=450&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/330738/original/file-20200427-145544-1ud4ur2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=450&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Notoungulata were hoofed, sometimes heavy-bodied grazing mammals that inhabited South America from 57 million years to 11,000 years ago.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Notoungulata#/media/File:Toxodon.jpg">ArthurWeasley/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Although it may seem an eternity since mammoths walked the Earth, our research suggests that some of the effects they had on the world around them can be resurrected without a Jurassic Park-style breakthrough in <a href="https://www.thoughtco.com/the-resurrection-of-extinct-animals-1091999">de-extinction</a>.</p><img src="https://counter.theconversation.com/content/132627/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Maarten van Hardenbroek van Ammerstol receives funding from UKRI/NERC. </span></em></p><p class="fine-print"><em><span>Ambroise Baker 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>
The historical record is full of surprises – and it could encourage conservationists to think more creatively.
Ambroise Baker, Lecturer in Biology, Teesside University
Maarten van Hardenbroek van Ammerstol, Lecturer in Physical Geography, Newcastle University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/125132
2019-11-20T19:16:38Z
2019-11-20T19:16:38Z
Extinction of ice age giants likely drove surviving animals apart
<figure><img src="https://images.theconversation.com/files/302600/original/file-20191120-524-tbd33d.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4281%2C2843&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Extinction of the woolly mammoth and other megafauna caused surviving animals to go their separate ways.</span> <span class="attribution"><span class="source">Wikimedia </span></span></figcaption></figure><p>As the world grapples with an extinction crisis, our large mammals are among the most endangered. These threatened species – rhinos, pandas, tigers, polar bears and the like – greatly influence their ecosystems. So what will happen to the smaller animals left behind?</p>
<p>Clues from a past megafaunal extinction could give us the answer. Thousands of years ago, many large mammals went extinct including mammoths, saber-toothed cats and Australia’s giant wombat. The extinctions happened at different times, shortly after human colonisation on each continent. </p>
<p>A study I led, <a href="https://science.sciencemag.org/content/365/6459/1305">published in the journal Science</a>, has found after the megafauna disappeared, many surviving mammal species went their separate ways. This weakened connections between species and may have made ecosystems more vulnerable. </p>
<p>As human activity drives modern megafauna towards extinction, our study gives valuable insights into the potential repercussions for smaller survivors.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/302594/original/file-20191120-474-vx0b6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/302594/original/file-20191120-474-vx0b6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=394&fit=crop&dpr=1 600w, https://images.theconversation.com/files/302594/original/file-20191120-474-vx0b6l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=394&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/302594/original/file-20191120-474-vx0b6l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=394&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/302594/original/file-20191120-474-vx0b6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=495&fit=crop&dpr=1 754w, https://images.theconversation.com/files/302594/original/file-20191120-474-vx0b6l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=495&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/302594/original/file-20191120-474-vx0b6l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=495&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many large mammals, such as the polar bear, are at risk of extinction.</span>
<span class="attribution"><span class="source">Henry H. Holdsworth/Natural Habi</span></span>
</figcaption>
</figure>
<h2>Surprise results</h2>
<p>Our team analysed the fossil records of 93 mammal species at hundreds of sites in North America, dating back up to 21,000 years, before the extinctions began.</p>
<p>We then determined the extent to which a particular species lived alongside others at each site. We found that after the extinction of large mammals, smaller mammals often distanced themselves from neighbouring species and were found together much less often than expected.</p>
<p>Surprisingly, this separation occurred while many survivors were claiming new habitats after the extinctions - which meant the potential space for co-habitation had actually increased.</p>
<p>The below diagrams show how animal species may have lived alongside each other before and after the megafauna extinctions. In the first, two species occupied the same area while co-habiting (orange sites). In the second, animals occupied the same area but were more segregated (red and yellow sites).</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/299572/original/file-20191030-17888-d1d512.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/299572/original/file-20191030-17888-d1d512.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=469&fit=crop&dpr=1 600w, https://images.theconversation.com/files/299572/original/file-20191030-17888-d1d512.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=469&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/299572/original/file-20191030-17888-d1d512.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=469&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/299572/original/file-20191030-17888-d1d512.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=589&fit=crop&dpr=1 754w, https://images.theconversation.com/files/299572/original/file-20191030-17888-d1d512.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=589&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/299572/original/file-20191030-17888-d1d512.png?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">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Created by Anikó Tóth</span></span>
</figcaption>
</figure>
<p>Such segregation suggests a change in interactions between species after the extinction event. Survivors may have rapidly become more abundant as large mammals disappeared, causing more competitive interactions. This could have prompted them to exclude each another from individual sites.</p>
<p>Our analysis suggests the repercussions of megafauna extinctions are still being felt today - leading to species increasingly segregated across continents, and interacting more opportunistically.</p>
<hr>
<p><strong><em>Hover over an animal silhouette to learn more about it. Notice the size difference between the largest North American fauna 12,000 years ago and today</em></strong></p>
<p><iframe id="tc-infographic-446" class="tc-infographic" height="400px" src="https://cdn.theconversation.com/infographics/446/8d436f7689ff8919ba426622354691e5c5fd820a/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<hr>
<h2>Animals need each other</h2>
<p>Connections between species large and small are the lifeblood of a functioning ecosystem, making it stable and resilient. Today’s large mammals are comparatively smaller than the megafauna of the last ice age. However, they still play a vital role in shaping ecosystems. </p>
<p>Just like in the past, modern large mammals may carry out pest control, aid seed dispersal and spread nutrients (by walking long distances and pooping out digested vegetation). This benefits humans and other species. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-we-need-to-protect-the-extinct-woolly-mammoth-122256">Why we need to protect the extinct woolly mammoth</a>
</strong>
</em>
</p>
<hr>
<p>Some large animals also shape and create homes for others. For example, elephants in Africa push over trees to create open grasslands, much like their Pleistocene-era cousin, the Columbian mammoth. This enables other species adapted to grasslands, such as gazelles and zebras, to share the habitat. </p>
<p>If elephants became extinct and no longer pushed over trees, grasslands would change and remaining animals may die or move away. In this way, the loss of interactions may make the ecosystem less stable and more vulnerable. </p>
<p>And animal extinctions have a snowball effect when it comes to species interactions. If half the species in a community go extinct, at least three quarters of the possible interactions in the system die with them.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/299794/original/file-20191101-26419-l2ixb5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/299794/original/file-20191101-26419-l2ixb5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/299794/original/file-20191101-26419-l2ixb5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/299794/original/file-20191101-26419-l2ixb5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/299794/original/file-20191101-26419-l2ixb5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=521&fit=crop&dpr=1 754w, https://images.theconversation.com/files/299794/original/file-20191101-26419-l2ixb5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=521&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/299794/original/file-20191101-26419-l2ixb5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=521&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Thylacoleo carnifex, the extinct marsupial lion.</span>
<span class="attribution"><span class="source">Image credit: Mauricio Antón</span></span>
</figcaption>
</figure>
<h2>Lessons for Australian conservation</h2>
<p>Although our study was restricted to North America, its findings have the potential to inform conservation efforts in Australia and shine a light into the past.</p>
<p>Australia’s fossil record and historical accounts document many species of large mammals which have become extinct. For example, more than 40,000 years ago humans <a href="https://science.sciencemag.org/content/292/5523/1888">wiped out large carnivores</a> such as the marsupial lion and more recently, the Tasmanian tiger. </p>
<p>People also introduced invasive medium-sized carnivores such as foxes and feral cats, the spread of which went unchecked for years. This devastated the unique and diverse suite of smaller Australian marsupials. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-end-to-endings-how-to-stop-more-australian-species-going-extinct-111627">An end to endings: how to stop more Australian species going extinct</a>
</strong>
</em>
</p>
<hr>
<p>Today, the extermination of feral cats is a major conservation problem in Australia. Had the marsupial lion still been around, feral cats may have been killed and marginalised by these larger animals, slowing their spread.</p>
<p>When planning animal conservation and management, it may be just as important to protect interactions as it is to save individual species. When introducing or eliminating species as part of environmental initiatives, it’s crucial to consider all possible interactions we are adding, as well as those we are taking away.</p><img src="https://counter.theconversation.com/content/125132/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aniko Blanka Toth 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>
After the woolly mammoth and other megafauna became extinct, surviving animals mingled less. This has big implications for modern conservation.
Aniko Blanka Toth, Postdoctoral Fellow, Macquarie University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/126696
2019-11-12T11:01:50Z
2019-11-12T11:01:50Z
Ice Age footprints of mammoths and prehistoric humans revealed for the first time using radar
<figure><img src="https://images.theconversation.com/files/301122/original/file-20191111-194656-43yhyp.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3000&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/columbian-mammoth-herd-winter-sets-mammoths-236426374?src=76c64e75-dbdd-410a-a46b-e16875e89596-1-3">Catmando/Shutterstock</a></span></figcaption></figure><p>The mammoth lumbers through our imaginations when we think about the world during the most recent Ice Age. They’re just one of many giant creatures that our ancestors lived alongside and which became extinct when the climate changed. The giant ground sloth – <a href="https://www.youtube.com/watch?v=S-vqQioKtQU">a large herbivore</a> which was endemic to the Americas – is another.</p>
<p>We can study these extinct animals from their bones – but also from the preserved footprints they left in mud. But these footprints are often hard to find – and while they can tell us about the presence of an animal, they don’t always tell us much about the animal itself, like how it walked, for instance. The giant ground sloth was unusual in that it walked on the outside of its feet. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/301096/original/file-20191111-194665-15o6i8p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/301096/original/file-20191111-194665-15o6i8p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/301096/original/file-20191111-194665-15o6i8p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/301096/original/file-20191111-194665-15o6i8p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/301096/original/file-20191111-194665-15o6i8p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/301096/original/file-20191111-194665-15o6i8p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/301096/original/file-20191111-194665-15o6i8p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1340&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Alkali Flat in New Mexico, USA. Ancient footprints of bygone creatures are preserved here.</span>
<span class="attribution"><span class="source">Matthew Robert Bennett</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>To help us, we turned to a new method which geologists and archaeologists use to image the hidden subsurface. <a href="https://www.youtube.com/watch?v=oQaRfA7yJ0g">Ground penetrating radar</a> was first used during the Vietnam War to reveal bunkers below ground. Today, engineers use it to spot cracks in railway tracks and girders. It works by sending signals into the ground which bounce back to reveal subsurface structures. It can be used for imaging big stuff, including buried walls in ancient ruins, but <a href="https://www.nature.com/articles/s41598-019-52996-8">in our new study</a>, we used it to find buried animal tracks from the Ice Age.</p>
<p>Our research team has been working for several years at <a href="https://www.nps.gov/whsa/index.htm%5D(https://www.nps.gov/whsa/index.htm">White Sands National Monument</a> in New Mexico in the US where one of the largest collection of vertebrate animal tracks from the Ice Age can be found. These tracks are preserved on a dried lake bed called Alkali Flat. Because they’re so difficult to make out, they’re locally referred to as “ghost tracks”. </p>
<p>Not only were we able to identify and map large tracks made by big animals such as mammoths and giant ground sloths, but to our surprise, we could also see those of the human hunters that stalked those animals. Imaging footprints of Ice Age giants, and their hunters, without excavating the tracks has huge advantages for their conservation. </p>
<p>Much of Alkali Flat is also used by the <a href="https://www.wsmr.army.mil/Pages/home.aspx">White Sands Missile Range</a>, where the American space programme began and the first nuclear bomb was detonated. In places, missile debris litters the ground. Being able to map where most of the tracks are will help prevent them from being erased.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=270&fit=crop&dpr=1 600w, https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=270&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=270&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=339&fit=crop&dpr=1 754w, https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=339&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/301095/original/file-20191111-194650-olovl7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=339&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 footprints from the last Ice Age at White Sands National Monument in New Mexico.</span>
<span class="attribution"><span class="source">Matthew Robert Bennett</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We also noticed something interesting beneath the mammoth tracks in the radar data. Below the base of the footprint, we consistently saw something resembling a hook in the radar image. This was completely unexpected. We weren’t sure what this was at first, but suspected that it might be due to the sediment below being compressed by the footprint. If so, this could provide crucial information about the way the animal walked. If this was indeed a pressure record, then it would likely match the pressure record from a close relative, like an elephant.</p>
<p>Foot pressure data for elephants, by the way, are rare – you can imagine how hard it is to get them into the lab and walking on delicate scientific instruments. Thanks to colleagues from <a href="https://www.rvc.ac.uk/">the Royal Veterinary College</a> in London and <a href="https://www.monash.edu/">Monash University</a>, we got our hands on some of this data. The pressure record for elephants turned out to be similar to the hook-like structures revealed in the radar data beneath the mammoth tracks. This led us to conclude that the radar was not only picking out the shape of the footprint, but also giving us much more data on the pressure exerted by the foot on the ground as the mammoth walked. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/301136/original/file-20191111-194675-1ugixeh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/301136/original/file-20191111-194675-1ugixeh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/301136/original/file-20191111-194675-1ugixeh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/301136/original/file-20191111-194675-1ugixeh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/301136/original/file-20191111-194675-1ugixeh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/301136/original/file-20191111-194675-1ugixeh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/301136/original/file-20191111-194675-1ugixeh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The pressure data from the mammoth footprints closely resembled those of modern elephants.</span>
<span class="attribution"><span class="source">Matthew Robert Bennett</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>For scientists studying the way extinct animals walk, this was very exciting. It’s the equivalent of getting an extinct animal to come into the lab and walk on a force plate. Best of all, the radar imaging allows us to study how these ancient creatures walked without having to disturb the footprint itself. </p>
<p>We think we’ll be able to use the same technique at other sites to image the pressure pattern beneath a dinosaur’s foot, just as if we’d managed to bring a living specimen into the lab. We should also be able to use this technology to map human footprints at other sites, especially where digging could be disruptive. There are famous sites, such as <a href="http://humanorigins.si.edu/evidence/behavior/footprints/laetoli-footprint-trails">Laetoli in Tanzania</a>, where footprints of the oldest human ancestors can be found. We’re not quite there yet, but given the right circumstances, we think it’s possible.</p><img src="https://counter.theconversation.com/content/126696/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Robert Bennett 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>
Scientists have worked out a new way to scan beneath the ground for footprints – and it’s revealing traces of an ancient world.
Matthew Robert Bennett, Professor of Environmental and Geographical Sciences, Bournemouth University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/122256
2019-08-28T04:23:27Z
2019-08-28T04:23:27Z
Why we need to protect the extinct woolly mammoth
<p>An audacious world-first <a href="https://cites.org/sites/default/files/eng/cop/18/prop/060319/E-CoP18-Prop-13.pdf">proposal</a> to protect an extinct species was debated on the global stage last week.</p>
<p>The plan to regulate the trade of woolly mammoth ivory was proposed, but ultimately withdrawn from an international conference on the trade of endangered species. </p>
<p>Instead, delegates agreed to consider the question again in three years, after a study of the effect of the mammoth ivory trade on global ivory markets. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/could-resurrecting-mammoths-help-stop-arctic-emissions-95956">Could resurrecting mammoths help stop Arctic emissions?</a>
</strong>
</em>
</p>
<hr>
<h2>Why protect an extinct species?</h2>
<p>The <a href="https://www.cites.org/eng/disc/text.php">Convention on the International Trade in Endangered Species of Wild Fauna and Flora</a> (CITES) is an international agreement regulating trade in endangered wildlife, signed by 183 countries. Every three years the signatories meet to discuss levels of protection for trade in various animals and their body parts. </p>
<p>The most audacious proposal at this year’s conference, which concluded yesterday in Geneva, was <a href="https://cites.org/sites/default/files/eng/cop/18/prop/060319/E-CoP18-Prop-13.pdf">Israel’s suggestion</a> to list the Woolly mammoth (<em>Mammuthus primigenius</em>) as a protected species. </p>
<p>Specifically, it aimed to list the woolly mammoth in accordance with the Convention’s “lookalike” provision. Once woolly mammoth ivory is carved into small pieces, it is indistinguishable from elephant ivory without a microscope. The proposal is designed to protect living elephants, by preventing “laundering” or mislabelling of illegal elephant ivory.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/289751/original/file-20190828-184202-1qs9up1.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">Once carved into small pieces, elephant and mammoth ivory are indistinguishable without a microscope.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/quinet/33182253770/in/photolist-SycHZC-23ZmzKM-at8W1Z-nf7bnH-Svv361-4LKPL2-8PBdYf-4LQ26S-8g7JpA-8g4shK-g1hJPE-TaFqQs-g1i3em-8PASkW-g1hVAv-g1i7G6-6a3XNE-5rBDY9-g1hGw3-g1i1gU-ikcGja-bBHPP5-nd4uCb-g1idsz-g1i7RY-g1hFRq-4LKPER-6nwj3R-Qytopg-jDWAen-pBkKzh-myDcAd-ikcL9W-gVRxRK-aTYqaV-oVCfZQ-Ns7cCk-fTdMir-7Kqj9n-8PASDG-bwrDUe-g1hQpN-be84C-g1hKCz-2fmdmS3-6a3XvU-dVkLp9-o6CSU2-dQmWJr-HBKAhG">Thomas Quine/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Had it passed, it would have been the first time an extinct species has been listed to save its modern-day cousins. Most populations of woolly mammoths went extinct after the last ice age, 10,000-40,000 years ago. </p>
<h2>Wait, you can trade mammoth ivory?</h2>
<p>The trade in woolly mammoth tusks lies at the convergence of Earth’s environmental crises. </p>
<p>As the climate crisis melts permafrost in the Siberian tundra, preserved mammoths bearing tusks as large as 4.2m long (weighing as much as 84kg) have been unearthed for the <a href="https://cites.org/sites/default/files/eng/cop/18/prop/060319/E-CoP18-Prop-13.pdf">first time in millennia</a>.</p>
<p>International trade in mammoth ivory is not illegal (except for import to India under domestic legislation), and the domestic trade of Woolly mammoth ivory is not banned by most countries. </p>
<p>While poorly documented, the main trade route for tusks is thought to be from Russia to Hong Kong and then mainland China for processing. </p>
<p><a href="http://savetheelephants.org/wp-content/uploads/2014/12/2014_ChinaConservationChallenge.pdf">Imports to Hong Kong</a> have increased dramatically from fewer than 9 tonnes per year from 2000 to 2003 to an average of 31 tonnes per year from 2007 to 2013. Similarly, <a href="http://www.pachydermjournal.org/index.php/pachy/article/view/420">one survey</a> found a fourfold increase in mammoth ivory sales in Macau between 2004 and 2015. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/its-time-to-break-the-deadlock-over-africas-ivory-trade-heres-how-122153">It's time to break the deadlock over Africa's ivory trade: here's how</a>
</strong>
</em>
</p>
<hr>
<h2>It’s not all mammoth</h2>
<p>While some of this mammoth trade is legitimate, plenty of traders are passing elephant ivory off as mammoth. Research has found that, while it’s <a href="https://cites-analysis.s3.amazonaws.com/uploads/proposal/attachments_en/79/Prop13WoollyMammoth_rev.pdf">very hard to tell</a> how much of the legal mammoth trade is actually (illegal) elephant ivory, tighter regulation may reduce opportunities for the laundering of elephant ivory.</p>
<p>The proposal would not ban trade altogether, but would require an exporting country to prove that specimens are mammoth ivory to get a permit. </p>
<p>Ivory laundering goes the other way as well. Grade A mammoth ivory can be carved and passed off as elephant ivory trinkets and enter the <a href="https://www.independent.co.uk/news/science/woolly-mammoth-dna-ivory-illegal-discovery-cambodia-wildlife-conservation-a8711241.html">illegal wildlife trade</a>.</p>
<p>The illegal wildlife trade claims the lives of 20,000-50,000 elephants annually and is the <a href="https://theconversation.com/illegal-wildlife-trade-is-one-of-the-biggest-threats-to-endangered-species-and-the-uk-is-a-key-player-85477">second greatest direct threat</a> to species survival. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/289750/original/file-20190828-184248-1ioo7cg.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"></a>
<figcaption>
<span class="caption">Selling elephant ivory is largely illegal around the world, but the mammoth trade creates a huge loophole.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/bluelemur/87500673/in/photolist-8JsUi-5ttc3q-6tYLBq-bqDVh3-6KViFx-5wPsS-88LmKo-8V478E-9sgj7Q-9tzfSP-6P1wiU-CWJrz-m2oT8B-f5iygM-XFCBRe-5hU4G7-XLRq-8Ga4GV-8JsUh-w96cU-gHjsW-6dqEYz-3X6ZQK-54p9UF-9rhfjw-DseMB-2emoWBN-44maxP-4qzthq-65Tz8e-9brEur-4z9Whv-8geF4-x9n1NK-fU9zds-6YnUEN-nsiiKw-ntk4Z3-6vSAbQ-9tzezc-JEMPR-5UEMw-6AMMcj-69NLRF-9oZVNq-bkHLP-9tzeeV-DJQUTp-4L51X9-9tzenF">Paul Williams/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Is it woolly thinking?</h2>
<p>The new proposal was not without its detractors. Some “ice ivory” sellers and carvers argue mammoth ivory should be promoted as an alternative to elephant ivory to meet market demand without poaching. Others maintain extinct species should be regulated by the laws and codes observed by the global antiquities trade. </p>
<p>While Israel has not taken positions on these points, the move would be in line with other global efforts to stem the tide of organised crime syndicates profiting from the illegal wildlife trade. </p>
<p>My <a href="https://lighthouse.mq.edu.au/article/when-will-we-stop-the-ivory-trade-in-australia">own research</a>, along with government inquiries around the world, has found legal markets in ivory, regardless of origin, can and will be exploited as conduits for illegal trade. </p>
<p>Further, a <a href="https://www.mdpi.com/2571-9408/2/3/142/htm">recent analysis</a> of the global online antiquities market found dealers and buyers have resoundingly poor legal literacy. Ethical dealer behaviour is highly inconsistent.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/to-save-the-african-elephant-focus-must-turn-to-poverty-and-corruption-117790">To save the African elephant, focus must turn to poverty and corruption</a>
</strong>
</em>
</p>
<hr>
<h2>A solution put on ice</h2>
<p>If it had passed, this proposal would have been a landmark achievement in the protection of elephants. Instead, Israel’s delegates ultimately withdrew the motion, in the face of vehement opposition from Russia, which is the primary exporter of mammoth ivory.</p>
<p>Delegates from Canada, the United States of America and the European Union said there was insufficient evidence to support the change. The various parties agreed to support a study into the mammoth ivory trade as a compromise, and Israeli delegates are hopeful the findings will reopen discussion at the next conference, three years from now.</p><img src="https://counter.theconversation.com/content/122256/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Zara Bending is affiliated with the Jane Goodall Institute Australia as a Board Director. However, her research into the illegal wildlife trade is conducted through the Centre for Environmental Law, Macquarie University. </span></em></p>
Melting Siberian permafrost is exposing long-dead mammoths, creating a new trade in mammoth ivory.
Zara Bending, Associate, Centre for Environmental Law, Macquarie University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/117234
2019-05-29T21:03:12Z
2019-05-29T21:03:12Z
Why giant human-sized beavers died out 10,000 years ago
<figure><img src="https://images.theconversation.com/files/276420/original/file-20190524-187165-x3te7f.jpg?ixlib=rb-1.1.0&rect=17%2C20%2C1979%2C1077&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The now-extinct giant beaver once lived from Florida to Alaska. It weighed as much as 100 kilograms, roughly the same as a small black bear.</span> <span class="attribution"><span class="source">Illustrated by Luke Dickey/Western University</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Giant beavers the size of black bears once roamed the lakes and wetlands of North America. Fortunately for cottage-goers, these mega-rodents died out at the end of the last ice age. </p>
<p>Now extinct, the giant beaver was once a highly successful species. Scientists have found its <a href="https://www.researchgate.net/profile/Richard_Hulbert/publication/268035498_Taxonomy_of_the_Pleistocene_giant_beaver_Castoroides_Rodentia_Castoridae_from_the_southeastern_United_States/links/545fd7b50cf27487b450ab66/Taxonomy-of-the-Pleistocene-giant-beaver-Castoroides-Rodentia-Castoridae-from-the-southeastern-United-States.pdf">fossil remains at sites from Florida</a> to <a href="http://www.beringia.com/exhibit/ice-age-animals/giant-beaver">Alaska and the Yukon</a>. </p>
<p>A super-sized version of the modern beaver in appearance, the giant beaver tipped the scales at 100 kilograms. But it had two crucial differences. </p>
<p>The giant beaver lacked the iconic paddle-shaped tail we see on today’s modern beavers. Instead it had a long skinny tail like a muskrat. </p>
<p>The teeth also looked different. Modern beaver incisors (front teeth) are sharp and chisel-like; giant beaver incisors were bulkier and curved, and lacked a sharp cutting edge. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/276422/original/file-20190524-187182-18co5m1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/276422/original/file-20190524-187182-18co5m1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=385&fit=crop&dpr=1 600w, https://images.theconversation.com/files/276422/original/file-20190524-187182-18co5m1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=385&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/276422/original/file-20190524-187182-18co5m1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=385&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/276422/original/file-20190524-187182-18co5m1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=484&fit=crop&dpr=1 754w, https://images.theconversation.com/files/276422/original/file-20190524-187182-18co5m1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=484&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/276422/original/file-20190524-187182-18co5m1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=484&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A side-by-side comparison of the modern beaver, Justin Bieber and the giant beaver, all part of Canada’s history.</span>
<span class="attribution"><span class="source">Illustration by Scott Woods/Western University</span></span>
</figcaption>
</figure>
<p>The species suddenly became extinct 10,000 years ago. The disappearance of the giant beaver coincides with that of many other large-bodied ice age animals, including the iconic woolly mammoth. But until now scientists didn’t know for certain why the giant rodent had died out. </p>
<h2>You are what you eat</h2>
<p>We need to understand how the giant beaver lived in order to explain how and why it died out. For example, did it run out of food? Did it get too cold or too hot for it to survive?</p>
<p>Other studies found the giant beaver thrived when the <a href="https://www.researchgate.net/publication/223266220_Oxygen_isotopic_determination_of_climatic_variation_using_phosphate_from_beaver_bone_tooth_enamel_and_dentine">climate was warmer and wetter</a>. They also noticed that giant beaver fossils were most commonly found in sediments that come from <a href="https://journals.iupui.edu/index.php/ias/article/view/7219">ancient wetlands</a>. But no one knew if the giant beaver behaved like the modern beaver. Did it also cut down trees? Or did it eat something completely different? </p>
<p>From an chemical perspective, you are what you eat! The food an animal consumes contains chemical signatures called <a href="https://www.futurelearn.com/courses/archaeology/0/steps/15267">stable isotopes</a> that are incorporated into body tissues such as bone. </p>
<p>These isotopic signatures remain stable over time, for tens of thousands of years, and provide a window into the past. No other studies have used stable isotopes to figure out the giant beaver’s diet. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=896&fit=crop&dpr=1 600w, https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=896&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=896&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1126&fit=crop&dpr=1 754w, https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1126&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/276421/original/file-20190524-187189-xqw6d0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1126&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Giant beaver skull.</span>
<span class="attribution"><span class="source">Florida Museum of Natural History</span></span>
</figcaption>
</figure>
<p>We studied fossil bones from giant beavers that lived in the Yukon and Ohio between 50,000 and 10,000 years ago. We looked at the stable isotope signatures of the ancient bone tissues. </p>
<p>The isotopic signatures linked to woody plants are different from those associated with aquatic plants. We discovered that the giant beaver was not cutting down and eating trees. Instead, <a href="https://doi.org/10.1038/s41598-019-43710-9">it was eating aquatic plants</a>. </p>
<p>This strongly suggests that the giant beaver was not an “ecosystem engineer” like the modern beaver. It was not cutting down trees for food or building giant lodges and dams across the ice age landscape. </p>
<p>Instead, this diet of aquatic plants made the giant beaver highly dependent on wetland habitat for both food and shelter from predators. It also made it vulnerable to climate change.</p>
<h2>Warm and dry climate</h2>
<p>Towards the end of the last ice age 10,000 years ago, the climate became increasingly warm and dry and wetland habitats began to dry up. Although the <a href="https://doi.org/10.1016/j.quascirev.2011.05.020">modern beavers and the giant beaver co-existed on the landscape for tens of thousands of years</a>, only one species survived. </p>
<p>The ability to build dams and lodges may have given the modern beaver a competitive advantage over the giant beaver. With its sharp teeth, the modern beaver could alter the landscape to create suitable wetland habitat where it needed it. The giant beaver couldn’t. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/276418/original/file-20190524-187182-ksw3mb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/276418/original/file-20190524-187182-ksw3mb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=295&fit=crop&dpr=1 600w, https://images.theconversation.com/files/276418/original/file-20190524-187182-ksw3mb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=295&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/276418/original/file-20190524-187182-ksw3mb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=295&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/276418/original/file-20190524-187182-ksw3mb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=371&fit=crop&dpr=1 754w, https://images.theconversation.com/files/276418/original/file-20190524-187182-ksw3mb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=371&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/276418/original/file-20190524-187182-ksw3mb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=371&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A giant beaver skeleton.</span>
<span class="attribution"><span class="source">Tessa Plint</span></span>
</figcaption>
</figure>
<p>This all fits into the puzzle that many research groups have been working on for decades: we all want to know what caused the <a href="http://www.nhm.ac.uk/our-science/our-work/origins-evolution-and-futures/extinction-large-mammals-late-quaternary.html">global megafauna extinction event</a> that occurred at the end of the last ice age and why so many species of large-bodied animals — woolly mammoths, mastodons and giant ground sloths — disappeared at roughly the same time. </p>
<p>Current evidence indicates that <a href="https://doi.org/10.1038/s41467-018-07897-1">a combination of climate change and human impact were the driving causes behind these extinctions</a>. </p>
<p>Studying the ecological vulnerabilities of long-extinct animals certainly poses its own unique challenges, but it is important to understand the impact of climate change on all species, past or present.</p><img src="https://counter.theconversation.com/content/117234/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tessa Plint received funding from NSERC, Faculty of Science (The University of Western Ontario), and the Arcangelo Rea Foundation. </span></em></p>
Scientists studied the fossilized bones of giant beavers to understand what they ate and whether the species could keep up with environmental change.
Tessa Plint, PhD researcher, Heriot-Watt University, and former graduate student, Western University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/107122
2018-11-23T11:36:38Z
2018-11-23T11:36:38Z
Huge crater discovered in Greenland – here’s how the impact may have wiped out the mammoths
<figure><img src="https://images.theconversation.com/files/246480/original/file-20181120-161627-186yzes.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An ice-sheet in Greenland's Inglefield Land is hiding the Hiawatha crater.</span> <span class="attribution"><span class="source">Natural History Museum of Denmark, Cryospheric Sciences Lab, NASA Goddard Space Flight Center, Greenbelt, MD, USA</span></span></figcaption></figure><p>Scientists have discovered a 31km wide impact crater beneath the <a href="https://geographic.org/geographic_names/name.php?uni=-2889853&fid=1988&c=greenland">Hiawatha glacier</a> in Greenland. The discovery, <a href="http://advances.sciencemag.org/content/4/11/eaar8173.full">published in Science Advances</a>, was made using airborne radar surveys which unveiled a circular bedrock depression beneath the ice. The presence of quartz and other grains and features on the ground helped the team confirm the finding – these showed signs of having been subjected to large shock pressures.</p>
<p>Analysis of the grains also shows that the impact was most likely made by an <a href="https://geology.com/meteorites/iron-meteorites.shtml">iron meteorite</a> more than 1km wide. It would have occurred during the Pleistocene, between about 12,000 and 3m years ago. This is by no means the only large impact crater on Earth, and research shows just how much such features can teach us about the history of our planet – including the evolution of life. So how could the Greenland impact have changed our planet?</p>
<p>Many of the oldest impacts from space occurred on our planet’s most ancient crusts and in the centre of its large, continental tectonic plates. Unfortunately, this crust is continually <a href="http://www.indiana.edu/%7Eg105lab/1425chap12.htm">renewed</a> – older rocks are destroyed by weathering processes and the remains are recycled into new rocks. This process destroys evidence of early impacts from large bodies. Also, many impact craters (often initially mistaken for extinct volcanic craters) have formed circular lakes, meaning that many features have been lost due to water erosion.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/246481/original/file-20181120-161633-ug5233.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/246481/original/file-20181120-161633-ug5233.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=422&fit=crop&dpr=1 600w, https://images.theconversation.com/files/246481/original/file-20181120-161633-ug5233.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=422&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/246481/original/file-20181120-161633-ug5233.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=422&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/246481/original/file-20181120-161633-ug5233.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=530&fit=crop&dpr=1 754w, https://images.theconversation.com/files/246481/original/file-20181120-161633-ug5233.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=530&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/246481/original/file-20181120-161633-ug5233.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=530&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Map of the bedrock topography beneath the ice sheet surrounding the impact crater.</span>
<span class="attribution"><span class="source">: Natural History Museum of Denmark, Cryospheric Sciences Lab, NASA Goddard Space Flight Center, Greenbelt, MD, USA</span></span>
</figcaption>
</figure>
<p>Despite this lack of evidence, we know that meteorite impacts can produce dramatic changes to the local environment. Larger ones can even have a drastic effect on the global environment – <a href="https://theconversation.com/could-asteroids-bombard-the-earth-to-cause-a-mass-extinction-in-ten-million-years-78937">bringing about mass extinctions</a>. The huge Chicxulub crater in Mexico, for example, is believed to have <a href="https://theconversation.com/revealed-asteroid-that-killed-the-dinosaurs-boiled-earths-atmosphere-36606">contributed to killing the dinosaurs</a>. </p>
<p>But how can one localised impact wipe out entire species? The initial impact and shock wave from an asteroid can wipe clear life within a substantial radius. Everything gets scorched from the heat of the impact – producing a desolate barren landscape. Shock waves passing through the body of the planet can also give rise to destructive earthquakes, tsunamis and volcanoes.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/246479/original/file-20181120-161624-zva6jw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/246479/original/file-20181120-161624-zva6jw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=364&fit=crop&dpr=1 600w, https://images.theconversation.com/files/246479/original/file-20181120-161624-zva6jw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=364&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/246479/original/file-20181120-161624-zva6jw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=364&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/246479/original/file-20181120-161624-zva6jw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=458&fit=crop&dpr=1 754w, https://images.theconversation.com/files/246479/original/file-20181120-161624-zva6jw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=458&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/246479/original/file-20181120-161624-zva6jw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=458&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Barringer crater.</span>
<span class="attribution"><span class="source">D. Roddy (LPI)/NASA</span></span>
</figcaption>
</figure>
<p>But it is the lasting effects of the impact that has the potential to cause the most serious changes. A large volume of debris ejected from the crater can travel far and spread all over the world. As a result, an increased number of particles in the atmosphere can block out sunlight, changing the climate and preventing photosynthesis – ultimately having a devastating effect on the food chain. Eventually the particles in the atmosphere fall back to Earth and light returns, along with life. The species that survive may be better able to prosper in a new world where many larger creatures, as was the case with the dinosaurs, have become extinct.</p>
<p>Clearly, such impact events have redirected the history of the Earth and paved the way to aid in the evolution of our own species. It is interesting to think about whether the world would be the same as it is today if the Chicxulub impact never happened – or even the impact found in Greenland.</p>
<h2>Greenland extinction?</h2>
<p>There is evidence that three impacts are possibly related to mass extinction events, including the <a href="http://www.ucmp.berkeley.edu/education/events/cowen1b.html">Cretaceous-Palegene events</a>
caused by Chicxulub. We also know that the majority of marine species and terrestrial vertebrates became extinct during the <a href="https://www.nationalgeographic.com/science/prehistoric-world/permian-extinction/">Permian Triassic event</a> some 252m years ago, thought to be caused by the asteroid impact leaving behind the <a href="https://en.wikipedia.org/wiki/Wilkes_Land_crater">Wilkes Land Crater</a> in Antarctica. Meanwhile, the <a href="https://geology.com/articles/popigai-crater-diamonds/">Popigia impact</a> in Siberia about 35m years ago is linked with the <a href="https://en.wikipedia.org/wiki/Eocene%E2%80%93Oligocene_extinction_event">Eocene-Oligocene event</a>, which wiped out many marine species.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/246482/original/file-20181120-161641-1yemukd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/246482/original/file-20181120-161641-1yemukd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/246482/original/file-20181120-161641-1yemukd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/246482/original/file-20181120-161641-1yemukd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/246482/original/file-20181120-161641-1yemukd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/246482/original/file-20181120-161641-1yemukd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/246482/original/file-20181120-161641-1yemukd.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">Kurt Kjær collecting sand samples at the front of Hiawatha Glacier.</span>
<span class="attribution"><span class="source">Svend Funder</span></span>
</figcaption>
</figure>
<p>All these impacts created craters a whopping 100km across or more (170km for Chicxulub), suggesting that the 31km crater in Greenland may not have been as devastating to the Earth. However, it would have drastically changed the local environment and reset the life race within that area. </p>
<p>If it is really true that the Greenland crater was created 12,000 years ago or more, it could explain a mysterious feature called the <a href="http://www.pnas.org/content/109/28/E1903">Younger Dryas event</a>. This was a sudden and dramatic change in climate – a glacial period about 12,900 to 11,700 years ago, followed by gradual climatic warming. Previously, scientists believed that this event was caused by a meteor exploding before impact, which would also have caused changes to the local environment.</p>
<p>The abrupt climate change is thought to have had a drastic effect on the large mammals of North America. For example, it is believed to have helped cause <a href="https://www.nationalgeographic.com.au/history/why-did-the-woolly-mammoth-die-out.aspx">extinction of the mammoths</a> and mastodons. We know that most woolly mammoth populations disappeared between 14,000 and 10,000 years ago. Early human hunter gatherers may have also had to adapt to cope with the change in climate from this event by changing hunting habits or even migrating to more suitable areas. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/247004/original/file-20181123-149320-1xd2o7n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/247004/original/file-20181123-149320-1xd2o7n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247004/original/file-20181123-149320-1xd2o7n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247004/original/file-20181123-149320-1xd2o7n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247004/original/file-20181123-149320-1xd2o7n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247004/original/file-20181123-149320-1xd2o7n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247004/original/file-20181123-149320-1xd2o7n.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">Woolly mammoth.</span>
<span class="attribution"><span class="source">wikipedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Clearly impact from space can have devastating consequences for life on Earth. So what if one hit today? The <a href="https://minorplanetcenter.net/">Minor Planet Centre</a> in Massachusetts, US, has been collecting and cataloguing the orbits of asteroids and comets since 1947, and NASA has a similar <a href="https://cneos.jpl.nasa.gov/about/basics.html">Near Earth Objects</a> programme. If a body is discovered to be on an intercept course there are <a href="https://theconversation.com/a-huge-asteroid-wiped-out-the-dinosaurs-but-what-danger-do-smaller-ones-pose-90133">prevention plans</a> in place, ranging from deflection and launching spacecraft to move the asteroids to a new orbit to blowing the asteroid up. Unfortunately, all these have their drawbacks and take years to plan – meaning this work may be too little too late. </p>
<p>Indeed, the late physicist Stephen Hawkins stated that an asteroid collision “<a href="https://www.washingtonpost.com/news/morning-mix/wp/2018/10/15/stephen-hawking-feared-race-of-superhumans-able-to-manipulate-their-own-dna/?noredirect=on&utm_term=.d2a63d9e4c2f">is the biggest threat</a> to our planet” and one that we cannot have control over. Despite all our monitoring and preparation, a large body may sneak up quickly. And, as previous impacts have taught us, while the damage may not be enough to destroy the world, it could drastically change it – maybe even for the better.</p><img src="https://counter.theconversation.com/content/107122/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kathryn Harriss receives funding from STFC. </span></em></p>
Meteorite impacts have fundamentally shaped the history of our planet.
Kathryn Harriss, Post-Doctoral Research Associate in Planetary Science, University of Kent
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/95956
2018-05-11T14:45:22Z
2018-05-11T14:45:22Z
Could resurrecting mammoths help stop Arctic emissions?
<figure><img src="https://images.theconversation.com/files/218613/original/file-20180511-34027-1cml58u.jpg?ixlib=rb-1.1.0&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/digital-illustration-mammoth-759825811?src=QiNqLwIPakxS_TRl5f54aQ-1-2">Shutterstock</a></span></figcaption></figure><p>If you managed to time travel back to Ice-Age Europe, you might be forgiven for thinking you had instead crash landed in some desolate part of the African savannah. But the chilly temperatures and the presence of six-ton shaggy beasts with extremely long tusks would confirm you really were in the Pleistocene epoch, otherwise known as the Ice Age. You’d be visiting the mammoth steppe, an environment that stretched from Spain across Eurasia and the Bering Strait to Canada. It was covered in grass, largely devoid of trees and populated by bison, reindeer, tigers and the eponymous “woolly” mammoth.</p>
<p>Unfortunately, both mammoth and most of the mammoth steppe ecosystem today have long but disappeared. But a group of <a href="https://www.theguardian.com/science/2017/feb/16/woolly-mammoth-resurrection-scientists">geneticists from Harvard</a> are hoping to change this by cloning living elephant cells that contain a small component of synthesised mammoth DNA. They claim that reintroducing such mammoth-like creatures to Arctic tundra environments could help stop the release of greenhouse gases from the ground and reduce future emissions as temperatures rise due to climate change. While this might sound like a far-fetched idea, scientists have actually been experimenting with something similar for over 20 years.</p>
<p>Arctic lands are covered by areas of ground known as permafrost that have been frozen since the Pleistocene. Permafrost contains <a href="https://www.nature.com/articles/ncomms13653">vast amounts of carbon</a> from dead plant life that is locked away by the extremely cold temperatures. The amount of carbon in these frozen stores is estimated to be about <a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013GL058088">twice as much as that currently in the atmosphere</a>. If it thaws out, microbes will break down soil organic material to release carbon dioxide and methane into the atmosphere.</p>
<p>As a result, permafrost and the associated carbon pools have been likened to “<a href="https://science.nasa.gov/sleeping-giant-arctic-permafrost-0">sleeping giants</a>” in our climate system. If they wake up, the resulting greenhouse gas emissions would raise global temperatures even further than currently projected, causing even greater global climate change (a process known as positive feedback).</p>
<h2>Natural geo-engineers</h2>
<p>This is where our shaggy friends may come in. Mammoths and other large herbivores of the Pleistocene continually trampled mosses and shrubs, uprooting trees and disturbing the landscape. In this way, they inadvertently acted as <a href="https://www.researchgate.net/publication/257110614_Mammoth_steppe_A_high-productivity_phenomenon">natural geo-engineers</a>, maintaining highly productive steppe landscapes full of grasses, herbs and no trees.</p>
<p>Bringing mammoth-like creatures back to the tundra could, in theory, help recreate the steppe ecosystem more widely. Because grass absorbs less sunlight than trees, this would cause the ground to absorb less heat and in turn keep the carbon pools and their greenhouse gases on ice for longer. Large numbers of the animals would also trample snow cover, stopping it from acting like insulation for the ground and allowing the permafrost to feel the effects of the bitter Arctic winters. Again, this would, in theory, keep the ground colder for longer.</p>
<p>This form of mammoth de-extinction and reintroduction could therefore promote grasslands and simultaneously slow the thawing of these frozen soils. So surely it’s worth it?</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/218576/original/file-20180511-52177-gred5z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/218576/original/file-20180511-52177-gred5z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/218576/original/file-20180511-52177-gred5z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/218576/original/file-20180511-52177-gred5z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/218576/original/file-20180511-52177-gred5z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/218576/original/file-20180511-52177-gred5z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/218576/original/file-20180511-52177-gred5z.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">Ukok Plateau, Siberia, is one of the last remnants of the mammoth steppe.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Ukok_Plateau#/media/File:Ukok_Plateau.jpg">Wikipedia/Kobsev</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p><a href="https://vimeo.com/207624364">Pleistocene Park</a> is an epic experiment in the Siberian Arctic that has been underway since 1996 and focused on investigating these processes. It is this park to which the Harvard team hope to deliver the first resurrected mammoth hybrid within the next decade.</p>
<p>Founded by Russian geophysicist <a href="http://reviverestore.org/projects/woolly-mammoth/sergey-zimovs-manifesto/">Sergei Zimov</a>, <a href="https://www.facebook.com/PleistocenePark/">the 16 square-kilometre park</a> is filled with <a href="http://science.sciencemag.org/content/308/5723/796.1.full?HITS=10&resourcetype=HWCIT&maxtoshow=&RESULTFORMAT=&FIRSTINDEX=0&firstpage=796&searchid=1&hits=10&volume=308&andorexacttitleabs=and&andorexactfulltext=and">around 100 animals</a> roaming free including bison, musk ox, moose, yaks, horses and reindeer. The park is designed to determine if the animals can disturb and fertilise the current ecosystem where little grows into highly productive pastures, as well as slowing or even reversing permafrost thaw. </p>
<p>I’ve been privileged to have visited the park a number of times, and have been amazed at the effort required to undertake such “big science” in this wilderness. We travelled for many hours along the massive Kolyma River to collect reindeer from the Arctic coast, and transported them by small boats to the park – no mean feat in these regions. Adding just another few animals to the experiment was exhausting. But it was totally exhilarating and made me question whether this was such a crazy idea after all.</p>
<p>The limited financial and personnel available to the park has made building and monitoring the project’s success difficult. Early evidence with extant species such as musk ox, reindeer and horse suggests animal presence is changing the park landscape structure and cooling the ground. </p>
<p>Recently, the park’s grasslands have <a href="https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/266991">been shown</a> to reflect more sunlight than the surrounding larch forest, which will reduce the heat penetrating the ground. Scientists have also taken 300 metre-long ground samples from across the landscape to measure the carbon storage in the park, and work out if it differs from that of the surrounding, non-disturbed landscape. </p>
<h2>Is it worth it?</h2>
<p>Much of the work relies on <a href="https://www.indiegogo.com/projects/bison-to-save-the-world--2#/">public crowdfunding</a> and the park is now seeking money to fill the park with temperature sensors and light sensors. It has already installed a 35-metre high <a href="https://www.esrl.noaa.gov/psd/iasoa/stations/cherskii#ui-tabs-2">flux tower</a> that continually monitors methane, carbon dioxide and temperature in the park’s atmosphere. Collecting convincing evidence to back up the theory clearly takes time and huge effort, but we should know soon if this bold plan could make a realistic solution to climate change.</p>
<p>Some scientists and conservationists <a href="https://www.nytimes.com/2017/03/20/science/revive-restore-extinct-species-dna-mammoth-passenger-pigeon.html">have questioned</a> whether resurrecting the mammoth is really worth it, comparing the high costs with the relative lack of funding for saving the world’s elephants. A key question is whether we need mammoth specifically to make these projects work? Could we not simply knock down trees manually, and then use existing animals? I guess this may depend on whether we decide to expand such an approach across far greater swathes of the Arctic, where human intervention will be costly or even near impossible in places.</p>
<p>Yet tackling global climate change needs ambitious, novel and often epic solutions, both to reduce emissions and to minimise the chance positive feedback from the Arctic that may cause untold damage to our climate system. I don’t know if bringing the mammoth back is the right approach, but at the moment we lack a decent solution for keeping the giant Arctic carbon deposits in the ground.</p><img src="https://counter.theconversation.com/content/95956/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Mann receives funding from the US National Science Foundation (NSF) and UK Natural Environmental Research Council (NERC). </span></em></p>
A 20-year-old experiment is testing whether filling the Arctic tundra with animals could keep carbon trapped in the ground.
Paul Mann, Senior Lecturer, Geography and Environmental Sciences, Northumbria University, Newcastle
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/76307
2017-04-18T19:49:59Z
2017-04-18T19:49:59Z
How English-style drizzle killed the Ice Age’s giants
<figure><img src="https://images.theconversation.com/files/165551/original/image-20170418-32703-1mh52ri.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Giant sloths: killed by rainy weather?</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3AWLA_hmns_Giant_ground_sloth_2.jpg">Kamraman/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Wet weather at the end of the last ice age appears to have helped drive the ecosystems of large grazing animals, such as mammoths and giant sloths, extinct across vast swathes of Eurasia and the Americas, according to our new research.</p>
<p>The study, <a href="http://nature.com/articles/doi:10.1038/s41559-017-0125">published in Nature Ecology and Evolution today</a>, shows that landscapes in many regions became suddenly wetter between 11,000 and 15,000 years ago, turning grasslands into peat bogs and forest, and ushering in the demise of many megafaunal species.</p>
<p>By examining the bone chemistry of megafauna fossils from Eurasia, North America and South America over the time leading up to the extinction, we found that all three continents experienced the same dramatic increase in moisture. This would have rapidly altered the grassland ecosystems that once covered a third of the globe.</p>
<p>The period after the world thawed from the most recent ice age is already very well studied, thanks largely to the tonnes of animal bones preserved in permafrost. The period is a goldmine for researchers – literally, given that many fossils were first found during gold prospecting operations.</p>
<p>Our work at the <a href="https://www.adelaide.edu.au/acad/">Australian Centre for Ancient DNA</a> usually concerns genetic material from long-dead organisms. As a result, we have accrued a vast collection of bones from around the world during this period. </p>
<p>But we made our latest discovery by shifting our attention away from DNA and towards the nitrogen atoms preserved the fossils’ bone collagen.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165559/original/image-20170418-32726-dsbdox.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"></a>
<figcaption>
<span class="caption">Lead Author Tim Rabanus-Wallace hunts for megafaunal fossils in the Canadian permafrost in 2015.</span>
<span class="attribution"><span class="source">Julien Soubrier</span></span>
</figcaption>
</figure>
<h2>Chemical signatures</h2>
<p>Nitrogen has two stable isotopes (atoms with the same number of protons but differing number of neutrons), called nitrogen-14 and nitrogen-15. Changes in environmental conditions can alter the ratio of these two isotopes in the soil. That, in turn, is reflected in the tissues of growing plants, and ultimately in the bones of the animals that eat those plants. In arid conditions, processes like evaporation preferentially remove the lighter nitrogen-14 from the soil. This contributes to a useful correlation seen in many grassland mammals: less nitrogen-14 in the bones means more moisture in the environment.</p>
<p>We studied 511 accurately dated bones, from species including bison, horses and llamas, and found that a pronounced spike in moisture occurred between 11,000 and 15,000 years ago, affecting grasslands in Europe, Siberia, North America, and South America.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165557/original/image-20170418-32705-ya7s1z.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"></a>
<figcaption>
<span class="caption">Alan Cooper inspects ice age bones from the Yukon Palaeontology Program’s collection, Canada, 2015.</span>
<span class="attribution"><span class="source">Julien Soubrier</span></span>
</figcaption>
</figure>
<p>At the time of this moisture spike, dramatic changes were occurring on the landscapes. Giant, continent-sized ice sheets were collapsing and retreating, leaving lakes and rivers in their wake. Sea levels were rising, and altered wind and water currents were bringing rains to once-dry continental interiors. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=581&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=581&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=581&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=730&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=730&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165562/original/image-20170418-32713-qqnmxv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=730&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 study shows that a peak in moisture occurred between the time of the ice sheets melting, and the invasion of new vegetation types such as peatlands (data shown from Canada and northern United States).</span>
<span class="attribution"><span class="source">http://nature.com/articles/doi:10.1038/s41559-017-0125</span></span>
</figcaption>
</figure>
<p>As a result, forests and peatlands were forming where grass, which specialises in dry environments, once dominated. Grasses are also specially adapted to tolerate grazing – in fact, they depend upon grazers to distribute nutrients and clear dead litter from the ground each season. Forest plants, on the other hand, produce toxic compounds specifically to deter herbivores. For decades, researchers have <a href="http://www.pnas.org/content/112/46/14301.full">discussed the idea</a> that the invading forests drove the grassland communities into collapse. </p>
<p>Our new study provides the crime scene’s smoking gun. Not only was moisture affecting the grassland mammals during the forest invasion and the subsequent extinctions, but this was happening right around the globe.</p>
<h2>Extinction rethink</h2>
<p>This discovery prompts a rethink on some of the key mysteries in the extinction event, such as the curious case of Africa. Many of Africa’s megafauna — elephants, wildebeest, hippopotamus, and so on — escaped the extinction events, and unlike their counterparts on other continents have survived to this day. </p>
<p>It has been argued that this is because African megafauna <a href="http://www.tandfonline.com.proxy.library.adelaide.edu.au/doi/abs/10.1080/03115510408619286">evolved alongside humans</a>, and were naturally wary of human hunters. However, this argument cannot explain the pronounced phase of extinctions in Europe. Neanderthals have existed there for at least 200,000 years, while anatomically modern humans arrive around 43,000 years ago. </p>
<p>We suggest instead that the moisture-driven extinction hypothesis provides a much better explanation. Africa’s position astride the Equator means that its central forested monsoon belt has always been surrounded by continuous stretches of grassland, which graded into the deserts of the north and south. It was the persistence of these grasslands that allowed the local megafauna to survive relatively intact.</p>
<p>Our study may also offers insights into the question of how the current climate change might affect today’s ecosystems. </p>
<p>Understanding how climate changes affected ecosystems in the past is imperative to making informed predictions about how climate changes may influence ecosystems in the future. The consequences of human-induced global warming are often depicted using images of droughts and famines. But our discovery is a reminder that all rapid environmental changes — wet as well as dry — can cause dramatic changes in biological communities and ecosystems.</p>
<p>In this case, warming expressed itself not through parched drought but through centuries of persistent English drizzle, with rain, slush and grey skies. It seems like a rather unpleasant way to go.</p><img src="https://counter.theconversation.com/content/76307/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alan Cooper receives funding from the Australian Research Council</span></em></p><p class="fine-print"><em><span>Matthew Wooller receives funding from US National Science Foundation</span></em></p><p class="fine-print"><em><span>Tim Rabanus-Wallace 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 burst of wet weather could have helped to kill off mammoths and other large herbivores, by transforming much of the world’s grasslands into bogs and forests and depriving megafauna of food.
Alan Cooper, Director, Australian Centre for Ancient DNA, University of Adelaide
Matthew Wooller, Professor, University of Alaska Fairbanks
Tim Rabanus-Wallace, PhD candidate, University of Adelaide
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/46632
2015-08-25T20:20:19Z
2015-08-25T20:20:19Z
Why banning the mammoth ivory trade would be a huge mistake
<figure><img src="https://images.theconversation.com/files/92905/original/image-20150825-17055-1qpxlcz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Would a ban on mammoth ivory endanger or save the elephant?</span> <span class="attribution"><a class="source" href="https://pixabay.com/en/elephants-trunks-tusks-mouths-844949/">Pixabay</a></span></figcaption></figure><p>There is widely held belief that the only way we can protect globally endangered species that are being poached for the international wildlife trade is to completely ban the trade. This is a dangerous misconception and will speed up extinction rather than prevent it. </p>
<p>Adrian Lister, a mammoth expert from University College London, recently suggested that <a href="http://www.independent.co.uk/environment/nature/mammoth-ivory-trade-should-the-prehistoric-species-be-protected--to-save-the-elephant-10467411.html">mammoths should be listed under the convention on international trade in endangered species</a> to keep their ivory from being laundered into an illegal trade in tusks. He argued that the mammoth trade is encouraging the poaching of elephants by keeping up the demand for ivory. </p>
<p>This is madness. Mammoths and mammoth ivory is not rare –
it is estimated that there are <a href="http://www.ucpress.edu/book.php?isbn=9780520253193">10 million mammoths</a> that remain incarcerated within the permafrost of the Arctic tundra. And in any case a ban on mammoth ivory would not stop the trade, it would simply drive it underground and attract the attention of organised crime groups. For example, in my own research I found that prices for illegally caught whale meat <a href="https://www.researchgate.net/publication/237020560_Cetacean_By-Catch_in_the_Korean_Peninsulaby_Chance_or_by_Design">rose very quickly when enforcement efforts intensified</a> and this in turn led to the trade being controlled by dedicated “professional” criminals. </p>
<p>In the same way, a ban on mammoth ivory would drive up prices and lead to many mammoth sites being excavated in clandestine fashion, without any associated scientific endeavours to garner knowledge and understanding of these great beasts. In fact the current situation supports collaboration between collectors and academics about new finds, to the benefit of scientific research. </p>
<p>A ban would not save the elephant either. In fact it would do the opposite and probably hasten its extinction in the wild. Although <a href="http://onlinelibrary.wiley.com/doi/10.1111/conl.12082/full">record levels of funding</a> are now being invested in enforcement and anti-poaching measures to tackle the crime, many species such as the rhino <a href="http://www.theguardian.com/environment/2015/jan/23/can-anything-stop-the-rhino-poaching-crisis">remain on the path to extinction</a> in the wild quite simply because bans aren’t working. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/92922/original/image-20150825-17069-e953fm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/92922/original/image-20150825-17069-e953fm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/92922/original/image-20150825-17069-e953fm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/92922/original/image-20150825-17069-e953fm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/92922/original/image-20150825-17069-e953fm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/92922/original/image-20150825-17069-e953fm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/92922/original/image-20150825-17069-e953fm.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">Woolly mammoth model at the Royal BC Museum in Victoria (Canada).</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Woolly_mammoth#/media/File:Woolly_mammoth.jpg">FunkMonk/wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Around the world, incentives to poach elephants and rhinos are increasing due to rising prices and growing relative poverty between areas of supply and centres of demand, and while trade bans can curtail supply it does not seem to have reduced demand in any measurable way. Indeed, high levels of protection can actually stimulate demand for a species due to something called the <a href="http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040415">anthropogenic allee effect</a>.</p>
<p>Economic theory and research can explain <a href="https://www.researchgate.net/publication/268693600_Towards_informed_and_multi-faceted_wildlife_trade_interventions">why this happens</a> and why we need to urgently reconsider our reliance on global trade bans. Where there is demand that is not very sensitive to price changes and strong enforcement of a ban, prices for illegal wildlife products will rise steeply, but have little overall effect on supply and consumption. This is especially true where organised criminal networks can circumnavigate the police and customs – <a href="https://www.researchgate.net/publication/259659182_Poaching_is_more_than_an_Enfo_rcement_Problem">a relatively easy trick</a> for countries mired in corruption. </p>
<h2>The need for bold moves</h2>
<p>In this situation we need to look beyond regulation and consider bold strategies that actually make economic sense. In particular we need policies that drive prices down and reduce the pressure on wild populations. To do this we should be considering introducing sustainable off-take mechanisms such as regulated trade, ranching and <a href="https://theconversation.com/why-killing-lions-like-cecil-may-actually-be-good-for-conservation-45400">wildlife farming</a>. If these new sources of supply are close substitutes, such as mammoth and elephant ivory, these mechanisms will certainly cause prices to fall and pressure on wild populations to reduce. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/92906/original/image-20150825-17093-15zi1w3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/92906/original/image-20150825-17093-15zi1w3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=452&fit=crop&dpr=1 600w, https://images.theconversation.com/files/92906/original/image-20150825-17093-15zi1w3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=452&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/92906/original/image-20150825-17093-15zi1w3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=452&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/92906/original/image-20150825-17093-15zi1w3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=568&fit=crop&dpr=1 754w, https://images.theconversation.com/files/92906/original/image-20150825-17093-15zi1w3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=568&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/92906/original/image-20150825-17093-15zi1w3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=568&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Cross sectioned mammoth tusk.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Woolly_mammoth#/media/File:Mammoth_tusk_slice.jpg">Cropbot/wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>We have seen this <a href="http://www.iucncsg.org/pages/Farming-and-the-Crocodile-Industry.html">happen successfully</a> with crocodilian species, where farmed animals have largely taken over the market and recent economic research in Canada shows that the sale of mammoth ivory into the ivory business in Asia has actually <a href="http://econ.ucalgary.ca/sites/econ.ucalgary.ca/files/naimafarahw15.pdf">led to lower prices for elephant ivory</a> saving thousands of elephants. </p>
<p>Basic economics tells us that when one introduces a substitute, especially a very close substitute, the price of the alternative product will fall. A recent analysis linked with empirical data predicts that the 84 tonnes of Russian mammoth ivory that was exported to Asia on average per annum over the period 2010-2012 would <a href="https://econ.ucalgary.ca/event/2015-04-15/elephants-and-mammoths-can-ice-ivory-save-blood-ivory-naima-farah">have actually reduced poaching</a> of wild elephants from 85,000 per year to around 34,000 elephants per year, primarily by reducing elephant ivory prices by about $100 per kilogram. </p>
<p>The policy implication is simple – the mammoth ivory trade should be legal and sustainably managed rather than banned – this will help save both the living elephant and the extinct mammoth.</p><img src="https://counter.theconversation.com/content/46632/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Douglas MacMillan receives funding from UK Research Councils and UK Government</span></em></p>
People arguing that a ban on mammoth ivory would help save elephants from extinction are wrong. Here’s why.
Douglas MacMillan, Professor of Conservation and Applied Resource Economics, University of Kent
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/45080
2015-07-23T18:09:22Z
2015-07-23T18:09:22Z
DNA evidence proves climate change killed off prehistoric megafauna
<figure><img src="https://images.theconversation.com/files/89552/original/image-20150723-22814-qcx4rq.jpg?ixlib=rb-1.1.0&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/File:Woolly_mammoth.jpg">FlyingPuffin</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Imagine a world populated by woolly mammoths, giant sloths and car-sized armadillos – 50,000 years ago more than 150 types of these mysterious large-bodied mammals roamed our planet. But by 10,000 years ago, two-thirds of them had disappeared. </p>
<p>Since the end of the 19th century, scientists have puzzled over where these “megafauna” went. In 1796, the famous French palaeontologist Georges Cuvier suggested a <a href="http://palaeo.gly.bris.ac.uk/palaeofiles/history/cuvier.xhtml">global catastrophe</a> had wiped them out. Others were appalled. The great Thomas Jefferson was so against Cuvier’s idea he <a href="http://www.vox.com/2015/4/13/8384167/thomas-jefferson-mastodons">sent an expedition</a> to try to find vast herds of these animals grazing contentedly in the American interior. The only thing anyone could say with certainty was there should be a lot more of them than we see today. </p>
<p>Alfred Wallace, who wrote the first paper on evolution by natural selection with Charles Darwin, <a href="http://wallace-online.org/thumbnails/GeographicalDistribution_illustrations.html">noted that</a> “we live in a zoologically impoverished world, from which all the hugest, and fiercest, and strangest forms have recently disappeared”. It’s one of the great historical whodunnits: what happened to the megafauna, and when did they disappear?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=460&fit=crop&dpr=1 600w, https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=460&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=460&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=579&fit=crop&dpr=1 754w, https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=579&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/89472/original/image-20150723-22821-1msx9hf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=579&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 two-tonne glyptodon survived until 10,000 years ago.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Glyptodon_(Riha2000).jpg">Pavel Riha</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>As with any good mystery, there are two main suspects: climate and humans.</p>
<p>The idea that our ancestors may have hunted the huge beasts to extinction has long been a popular view, particularly as the spread of humans around the world appears closely associated with their demise. Several major criticisms continue to be levelled at this theory, the most popular being that many large animals are still present in Africa, despite it having the longest record of occupation by people. Others in turn argue that humans co-evolved alongside megafauna in Africa for millions of years, giving animals time to <a href="http://ngm.nationalgeographic.com/ngm/0509/resources_geo2.html">learn from human behaviour</a>.</p>
<p>The alternative is that a rapidly changing climate caused the habitat of the megafauna to shrink or disappear. As the planet warmed out of the last ice age 12,000 years ago, many animals would have struggled to adapt to the new environment. A major criticism here is that there have been other major climatic changes in the past, some of which have been <a href="https://theconversation.com/sudden-global-warming-55m-years-ago-was-much-like-today-35505">equally extreme and rapid</a>. What could have been so different with this most recent warming?</p>
<p>In a research paper published in the journal <a href="http://www.sciencemag.org/content/early/2015/07/22/science.aac4315.abstract">Science</a>, we report new advances in ancient DNA, carbon dating and climate reconstruction that finally give some answers. Previously, as long as species appeared to survive in the fossil record the interpretation had been that nothing significant had happened for tens of millennia. </p>
<p>But thanks to ancient DNA analysis of megafaunal bones we now know that this approach has missed a series of events throughout the past 50,000 years when major parts of a species’ genetic diversity, or even the whole species itself, disappeared. Alongside this, more accurate carbon dating of the fossil remains shows these extinctions did not all happen at a single time but were staggered through time and space.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/89473/original/image-20150723-22830-1v6hcpd.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">The authors recently discovered this DNA-filled mammoth vertebrae preserved in ice, while doing fieldwork in northern Canada.</span>
<span class="attribution"><span class="source">Kieren Mitchell</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>It’s important to realise the backdrop to these extinctions was a wildly fluctuating climate. The ice age of the northern hemisphere was not one long frigid wasteland. Instead, frozen conditions were punctuated by many short, rapid warming periods, known as <a href="http://www.jstor.org/stable/30069381?seq=1#page_scan_tab_contents">interstadials</a>, where temperatures would soar from 4 to 16˚C within just a few decades and last for hundreds to thousands of years. They represent some of the most profound climate changes detected in the recent geological past. </p>
<p>When we precisely compared the dates for European and American extinctions with climate records, we were amazed to find they coincided with the abrupt warming of the interstadials; in stark contrast there is a complete absence of extinctions at the height of the last ice age. As temperatures rose during the interstadials, dramatic shifts in global rainfall and vegetation patterns would have placed the megafauna under immense stress. Those that could not adapt to the rapidly changing conditions would have quickly succumbed. The European cave lion, for instance (<em>Panthera leo spelaea</em> in the chart below), survived through periods when much of the continent was covered in ice, only to go extinct during relatively benign conditions around 14,500 years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=309&fit=crop&dpr=1 600w, https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=309&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=309&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=389&fit=crop&dpr=1 754w, https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=389&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/89469/original/image-20150723-22852-9nmf7j.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=389&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Megafaunal extinctions mapped against climate change. Temperature history is shown along the bottom; the black and red bars represent 95% confidence ranges. Most animals went extinct during warm interstadial periods (shaded brown), and the last ice age (shaded blue) had almost no effect.</span>
<span class="attribution"><span class="source">Cooper et al</span></span>
</figcaption>
</figure>
<p>There seems little doubt humans would have contributed to extinctions, however. While the dramatic climate shifts were the major driver in megafaunal extinction events, humans would have applied the <em>coup de grâce</em> to populations already suffering major stress. </p>
<p>In one likely scenario, humans would have concentrated their hunting efforts along dispersal routes, killing the few bold individuals moving out to re-establish an extinct population, causing localised extinctions to expand into larger and larger areas, that would have eventually led to an irreversible ecosystem collapse. It’s likely the scattered pattern of extinctions and the difficulty of detecting them from fossils alone is why the relationship with warming events has not been detected before.</p>
<p>So what does this mean for the future? Well for a start, rapidly increasing temperatures are not good news for the megafauna that survived the last warming. In many ways the rise of atmospheric CO<sub>2</sub> levels and resulting warming effects are expected to have a similar rate of change to the onset of past interstadials, heralding another major phase of <a href="https://theconversation.com/most-large-herbivores-now-face-extinction-our-study-shows-41102">large mammal extinctions</a>. </p>
<p>This seems all the more likely thanks to our “success” in developing the planet’s surface, breaking up areas of natural habitat and disrupting any connectivity that once existed between areas. Migration is becoming increasingly less of an option for species struggling to adapt to changing temperatures with little chance of back filling from neighbouring areas for re-establishing populations. Even after all these years, megafauna are providing a precious lesson from the past.</p><img src="https://counter.theconversation.com/content/45080/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Turney receives funding from the Australian Research Council.
</span></em></p><p class="fine-print"><em><span>Alan Cooper receives funding from the Australian Research Council, US NSF, and National Geographic Society.</span></em></p>
Animals that couldn’t adapt to rapid warming quickly succumbed.
Christian Turney, Professor and ARC Laureate Fellow, UNSW Sydney
Alan Cooper, Director, Australian Centre for Ancient DNA, University of Adelaide
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/42864
2015-06-10T13:05:13Z
2015-06-10T13:05:13Z
Sci-fi and Jurassic Park have driven research, scientists say
<figure><img src="https://images.theconversation.com/files/84516/original/image-20150610-6814-1g3xc98.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Roaming among the dinosaurs in Jurassic World.</span> <span class="attribution"><span class="source">ILM/Universal Pictures and Amblin Entertainment</span></span></figcaption></figure><p>The park is almost open. Two decades on and Jurassic Park has morphed into Jurassic World, the one and only dinosaur theme park. Science has apparently evolved too: the genetically-engineered dinosaurs are to take a secondary role to a new star of the show, a genetically-engineered hybrid, worryingly named <a href="http://www.jurassicworld.com/dinosaurs/indominus-rex/"><em>Indominus Rex</em></a>. Undoubtedly, chaos will ensue.</p>
<p>In the wake of the 1993 Jurassic Park film, scientists who have anything – or even nothing – to do with palaeontology or molecular biology are almost always asked the same question: “Can we resurrect a dinosaur?” The answer is always an emphatic no. </p>
<p>But to some extent, Jurassic Park did actually drive and develop the science and technology of ancient DNA research. I’ve spent the past year interviewing scientists about the history of ancient DNA research and the effects of Jurassic Park on their work as part of my doctoral degree.</p>
<h2>Hope and hype</h2>
<p>Ancient DNA research walks a fine line between science and science fiction, something stressed by its short but sensational history. Its beginnings tell a story of science, speculation, hope, and hype – and Michael Crichton, the author of the original Jurassic Park novel, was quick to pick this up. Dinosaurs were always a frequent feature of museums, but breaking open perfectly preserved bones to discover what was inside was a novelty.</p>
<p>In the 1980s, innovative ideas behind the search for DNA from ancient amber insects to extinct museum specimens provided the inspiration for Jurassic Park, and the predictable and catastrophic consequences of bringing dinosaurs back. What wasn’t foreseeable was the incredible impact the movie would have – and still has – on the development of ancient DNA research.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/84524/original/image-20150610-6804-13eqt6z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/84524/original/image-20150610-6804-13eqt6z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/84524/original/image-20150610-6804-13eqt6z.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/84524/original/image-20150610-6804-13eqt6z.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/84524/original/image-20150610-6804-13eqt6z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/84524/original/image-20150610-6804-13eqt6z.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/84524/original/image-20150610-6804-13eqt6z.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">
<figcaption>
<span class="caption">Indominus Rex.</span>
<span class="attribution"><span class="source">ILM/Universal Pictures and Amblin Entertainment</span></span>
</figcaption>
</figure>
<p>It was in the 1990s that the feverish search for the most ancient DNA from the most iconic fossils began. Scientists call it the “Wild West” and even “the Jurassic Park phase”. It is during this time that Jurassic Park’s influence is most evident.</p>
<p>As well as being the year that the film was released, 1993 also marked a turning point in the world of ancient DNA research: a team of researchers extracted and sequenced DNA from a 125-130m-year-old ancient weevil in Lebanese amber. <a href="http://www.nature.com/nature/journal/v363/n6429/abs/363536a0.html">The results</a> were reported in <a href="http://www.nature.com/">Nature</a> on June 10 – one day after the Jurassic Park premiere and one day before its release in cinemas across the United States. </p>
<p>The timing was not a coincidence – and this didn’t go unnoticed. One scientist I spoke to remarked that it was “absolutely extraordinary that a scientific journal like Nature would hold on to an article to wait for the opening day of a movie”. It “caused a huge media splash”. </p>
<h2>Dinosaur resurrection</h2>
<p>That year, Jack Horner – palaeontologist and scientific consultant to Jurassic Park – proposed a project to investigate DNA from dinosaurs to the National Science Foundation. The grant was funded the same year the film was released and this, too, was no coincidence. One scientist told me that they thought NSF funded the project simply because of the film: “It was the perfect time for it”. (This, and all subsequent attempts at securing dinosaur DNA, have failed).</p>
<p>In addition to swaying publication timing and grant funding, Jurassic Park created a new generation of “geeky but glamorous” scientists. One researcher said: “Ancient DNA sounds cool” or “sounds like it should be cool”: “That really does stem back to Jurassic Park. It is still the legacy of that. That’s when it entered the popular consciousness”. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/84525/original/image-20150610-6787-42yy73.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/84525/original/image-20150610-6787-42yy73.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/84525/original/image-20150610-6787-42yy73.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/84525/original/image-20150610-6787-42yy73.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/84525/original/image-20150610-6787-42yy73.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=510&fit=crop&dpr=1 754w, https://images.theconversation.com/files/84525/original/image-20150610-6787-42yy73.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=510&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/84525/original/image-20150610-6787-42yy73.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=510&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Behind the scenes.</span>
<span class="attribution"><span class="source">Chuck Zlotnick</span></span>
</figcaption>
</figure>
<p>But the influence of Hollywood has not always been positive. Another scientist said:</p>
<blockquote>
<p>It raised expectations about DNA and what ancient DNA could do. Unfortunately, because it was made by a great director – Steven Spielberg – it’s a film that sticks in people’s minds. </p>
</blockquote>
<p>For this scientist, the movie and the media around it diminishes and even deceives the public about ancient DNA research: </p>
<blockquote>
<p>When I give a talk about ancient DNA, they put up a poster and it has a <em>dinosaur</em> on it. I’ve objected. I’ve said: ‘there’s <em>no</em> dinosaur DNA. You should <em>not</em> show the dinosaur’. It’s had a bad influence.</p>
</blockquote>
<p>But for better or worse, the Jurassic Park legacy lives on. The rhetoric of resurrection has certainly blurred boundaries between fantasy and reality – especially in the media.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/84526/original/image-20150610-6804-1652tpe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/84526/original/image-20150610-6804-1652tpe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/84526/original/image-20150610-6804-1652tpe.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/84526/original/image-20150610-6804-1652tpe.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/84526/original/image-20150610-6804-1652tpe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/84526/original/image-20150610-6804-1652tpe.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/84526/original/image-20150610-6804-1652tpe.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Alive and well.</span>
<span class="attribution"><span class="source">Universal Pictures and Amblin Entertainment</span></span>
</figcaption>
</figure>
<h2>Bringing mammoths back</h2>
<p>The focus of this interest, however, has somewhat shifted. These days, questions are less about dinosaur resurrection and more about <a href="https://theconversation.com/produce-mammoth-stem-cells-says-creator-of-dolly-the-sheep-16335">mammoth de-extinction</a>, particularly after the discovery of potentially viable mammoth DNA in 2013.</p>
<p>When I ask ancient DNA researchers about mammoth de-extinction the overwhelming majority ask me: “Why would you want to de-extinct a mammoth?” De-extinction requires significant technological and biological improvements, as well as philosophical, political and ethical considerations.</p>
<p>The ethics of de-extinction runs both ways. Palaeontologist Michael Archer argues we have moral obligation to resurrect extinct species like the Tasmanian tiger, because we – through population and predation increase – were the cause of their demise. But most scientists disagree and argue time and money should be spent conserving the current environment. One researcher said: </p>
<blockquote>
<p>If aliens landed and looked around then they’d be pretty surprised to see that we had decided to piss away the last of our resources on trying to bring back the mammoth.</p>
</blockquote>
<p>Jurassic Park has certainly left a long and lasting legacy. It is a legacy that makes us question our motivation for de-extinction. And with the release of Jurassic World, this debate over science or sensation is set to take centre stage once again.</p>
<p><em><strong><a href="https://theconversation.com/found-preserved-dinosaur-cells-but-sadly-scientists-still-cant-build-jurassic-world-42959">Read more here</a> about the discovery of preserved cells in Canadian dinosaur bones.</strong></em></p><img src="https://counter.theconversation.com/content/42864/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth Jones receives funding from the Department of Science and Technology Studies at UCL, the Division of Paleontology at American Museum of Natural History and the British Society for the History of Science.</span></em></p>
Science-fiction, to some extent, can indeed create science.
Elizabeth Jones, PhD Candidate in Science and Technology Studies, UCL
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/42818
2015-06-08T20:08:22Z
2015-06-08T20:08:22Z
Before we build Jurassic World we need to study recent extinctions
<p>It’s hard to have a conversation about bringing extinct creatures back to life without a tip-of-the-hat to <a href="http://www.imdb.com/title/tt0107290/">Jurassic Park</a>, or the latest instalment, <a href="http://www.imdb.com/title/tt0369610/">Jurassic World</a>, due out Thursday. Massive people-eaters escaping their bonds and ravaging humanity may make good cinema but the arguments both for and against de-extinction are more subtle and wide ranging.</p>
<p>De-extinction is based on the concept that extinction need not be forever. One way to save those animals and plants that we thought were already lost is via genomic techniques, which can link molecular biology and conservation.</p>
<p>The image of dinosaurs walking the modern-day Earth may be enough to turn some people on or off the idea immediately. But for a myriad of reasons, these great beasts of the long distant past aren’t among the immediate candidates for de-extinction.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/o8ZIxVxxYAQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Instead, creatures such as the <a href="http://www.bbc.com/news/science-environment-25052233">Pyrenean Ibex</a>, the <a href="http://www.wired.com/2013/03/passenger-pigeon-de-extinction/">Passenger Pigeon</a> and our own <a href="http://www.examiner.com.au/story/1381582/thylacine-can-return-from-dead/">Tasmanian Tiger</a> – all animals that have gone extinct in living memory – are in the sights of scientists around the world as part of the <a href="http://longnow.org/">The Long Now Foundation</a>.</p>
<p>Professor Mike Archer of the University of New South Wales is a member of this foundation, and in a 2013 <a href="https://youtu.be/y2xxZ9RKEzM">TEDx DeExtinction talk</a> he said:</p>
<blockquote>
<p>[…] if it’s clear that we [humanity] exterminated these species then I think we not only have a moral obligation to see what we could do about it, but I think we’ve got a moral imperative to try to do something, if we can.</p>
</blockquote>
<h2>Not yet extinct, but close</h2>
<p>In addition to the prospect of returning the recent dead, the technologies developed for de-extinction may also come to the rescue of currently living (extant) but endangered animals.</p>
<p>For those close to the edge of extinction, one of the major problems hindering conservation is a lack of genetic diversity within surviving populations. Oliver Ryder, director of genetics at the San Diego Zoo Institute for Conservation and Research, said that <a href="http://blogs.sandiegozoo.org/2015/02/26/strategy-to-save-northern-white-rhino-is-launched-new-genetic-technologies-offer-hope-for-species/">cryo-preserved tissues</a> may be used to improve the genetic variability and reproductive vigour of the critically endangered Northern White Rhino.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/84064/original/image-20150605-14138-1919zau.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">Facing extinction: one of the last remaining Northern White Rhinos.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/djmccrady/3278825295/in/photostream/">Flickr/Don McCrady</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>With many of our charismatic extant creatures sharing the same crisis, the development of these tools could be a blessing.</p>
<p>Growing interest and support for de-extinction would be particularly beneficial to natural history museums collections. The bones, soft tissue samples and skins collected from distinct populations of species could provide a diverse databank of DNA for de-extinction programs.</p>
<p>But de-extinction is a field that is controversial in the public eye, and at times, among scientific peers. David Burney, Professor of Conservation Paleobiology at Hawaii’s National Tropical Botanical Garden, <a href="http://longnow.org/revive/1stde-extinction/">has said</a> that if de-extinction is technically possible, then it’s inevitable, so it might as well be embraced. That view is not an argument with unanimous support.</p>
<p>The most common arguments against de-extinction hail from conservationists themselves. De-extinction is an expensive process and the concern is that the limited resources allocated to the conservation of living organisms may be diverted to pay for de-extinction research.</p>
<p>While the cost of gene sequencing and the molecular techniques have been decreasing rapidly, these are not the only costs in implementing de-extinction. Re-introducing and managing small populations of animals, managing captive breeding and providing suitable habitat will be expensive. So too will be closely monitoring populations, protecting them from the causes of their initial extinction and studying the effect of re-introduced species.</p>
<p>So, if evenly pitted against its currently employed counterparts for conservation management, how will de-extinction fare and how will we predict the potential effectiveness of a novel method?</p>
<p>One likely analogue is “rewilding”, the process of replacing extinct species with ecological analogues from other environments, for example, re-introducing Tasmanian Devils onto the Australian mainland.</p>
<p>Previous attempts have been met with controversy. The question of conserving species compared with preserving ecosystem functionality is one that perhaps deserves more considered public debate than it has received.</p>
<p>Perhaps returning the missing species, even if it went extinct long before living memory, would face the same critique. Not everyone is in favour of wild animals in their backyard, whether back from extinction or not.</p>
<h2>Back from the dead but not the right home</h2>
<p>But what of the other side of the coin? What if we resurrect species that belonged in ecosystems that no longer exist?</p>
<p><a href="http://www.pleistocenepark.ru/en/">Pleistocene Park</a>, in northern Siberia, is an experiment to show that over-hunting by humans caused both the animals – including mammoths, woolly rhinoceroses, bison, horses, musk oxen, elk, saiga and yaks – and their Pleistocene habitats to vanish from the region.</p>
<p>Through grazing experiments, scientists are attempting to restore the ecosystem to what it was more than 10,000 years ago. But the missing density of herbivorous animals (such as the extinct mammoths) is said to be choking the tundra with moss.</p>
<p>If human alteration of the environment has been the main cause of extinctions over the last 1,000 years, how are we going to give it back? And which creatures that have adapted to the new landscape will we sacrifice to do so?</p>
<p>Given there have been successions of changing landscapes, each with its own biota, which one will we reinstate? If we were not able to protect these environments and the creatures that inhabited them in the past, why do we think we could do it now?</p>
<p>If we bring them back before we have halted our current rate of extinction, will we simply be dooming them to a second extinction event, a title currently only held by the Pyrenean Ibex?</p>
<p>Archer, a keen supporter of de-extinction, raised this point in his TEDx talk in relation to the Tasmanian Tiger:</p>
<blockquote>
<p>So, could we put it back? Yes. Is that all we would do? And this is an interesting question. Sometimes, you might be able to put it back, but is that the safest way to make sure it never goes extinct again? And I don’t think so.</p>
<p>I think gradually, as we see species all around the world, it’s kind of a mantra, that wildlife is increasingly not safe in the wild – we’d love to think it is, but we know it isn’t – we need other parallel strategies coming online.</p>
</blockquote>
<p>Among all the questions, one thing seems clear: the application of de-extinction will need to be considered carefully on a case-by-case basis, with both forethought and public support.</p>
<p>For now the argument that de-extinction will be a boost to the resources of the conservation movement in the long term, rather than a drain on its already limited funds, is based on a mix of genuine hope and economic speculation.</p>
<p>It isn’t yet known if funding will follow excitement, or if the public will support the return of real past ecosystems.</p>
<p>Unlike some, we don’t believe that technical possibility necessitates inevitability, and so it is time to give some serious thought to de-extinction, when and why it could be applied, and to the conservation of the environment we still have. There is a long way to go before we consider a real Jurassic Park.</p>
<hr>
<p><strong>See also:</strong> <a href="https://theconversation.com/creating-dinosaurs-why-jurassic-world-could-never-work-35484">Creating dinosaurs: why Jurassic World could never work</a></p><img src="https://counter.theconversation.com/content/42818/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Jurassic World is opening in cinemas this Thursday and again raises the idea of resurrecting extinct creatures. But there’s plenty of other contenders before we even think of recreating dinosaurs.
Tamara Fletcher, Research Associate in Palaeontology, The University of Queensland
Caitlin Syme, PhD Candidate, Vertebrate Palaeontology, The University of Queensland
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/35457
2014-12-18T06:21:43Z
2014-12-18T06:21:43Z
For me, the idea of de-extinction is now as dead as a dodo
<figure><img src="https://images.theconversation.com/files/67529/original/image-20141217-31028-1jrjtpw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dodos are best kept in museums these days.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/wheatfields/2070548675">net_efekt</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>My wildlife friends and I often talk about what species we would bring back from extinction. I am torn between the dodo and the <a href="http://www.naturalworlds.org/thylacine/">thylacine</a>, also known as the Tasmanian tiger. This was once a speculative, sci-fi debate but not anymore. Ever since Dolly the sheep was cloned, conservation biologists have muted the idea and the process of de-extinction – bringing back dead species – is coming closer to reality. </p>
<p>De-extinction can be achieved by one of two means: selective breeding <a href="https://theconversation.com/produce-mammoth-stem-cells-says-creator-of-dolly-the-sheep-16335">or cloning</a>. In the selective breeding method we try to re-create extinct species such as the aurochs (extinct large cattle from Europe and Asia) by looking for their surviving genes among existing cattle and breeding animals to favour these genes. Then you compare the genome of the resulting animals with that for aurochs until you have <a href="http://www.telegraph.co.uk/news/earth/wildlife/7011035/Giant-cattle-to-be-bred-back-from-extinction.html">what is genetically an auroch</a>. </p>
<p>The second method essentially involves finding the DNA of an extinct species and inserting it into a recipient egg cell and recipient animal – the cloning process. This second process is limited to species that have gone extinct more recently (hundreds of years) because you need to find intact DNA, so I am afraid <a href="https://theconversation.com/resurrecting-dinosaurs-will-remain-a-jurassic-park-dream-18132">there will be no Jurassic Park</a>. We would also need to find DNA from several different individuals otherwise we would end up with problems due to inbreeding such as those seen in <a href="http://www.slate.com/articles/health_and_science/science/2012/12/white_tiger_controversy_zoos_shouldn_t_raise_these_inbred_ecologically_irrelevant.html">white tigers</a>.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/67535/original/image-20141217-31052-19atcl0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/67535/original/image-20141217-31052-19atcl0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=776&fit=crop&dpr=1 600w, https://images.theconversation.com/files/67535/original/image-20141217-31052-19atcl0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=776&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/67535/original/image-20141217-31052-19atcl0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=776&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/67535/original/image-20141217-31052-19atcl0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=975&fit=crop&dpr=1 754w, https://images.theconversation.com/files/67535/original/image-20141217-31052-19atcl0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=975&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/67535/original/image-20141217-31052-19atcl0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=975&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Modern cows are descended from the auroch.</span>
<span class="attribution"><a class="source" href="http://en.wikipedia.org/wiki/File:Aurochse.jpg">Auerochse</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Unsurprisingly the “instant fix” of cloning has received more interest as it would not depend on many generations of captive breeding. A wide range of species have been suggested for cloned de-extinction from the dodo to the <a href="https://theconversation.com/produce-mammoth-stem-cells-says-creator-of-dolly-the-sheep-16335">woolly mammoth</a>. </p>
<p>Initially, I liked the idea. I’d love to see a dodo in a zoo or even better to see wild woolly mammoths on an ecotourism trip to the steppes of Siberia. But such meddling raises a host of questions.</p>
<p>For instance, an African elephant would be the obvious recipient for woolly mammoth DNA. But as mammals learn a considerable part of their behaviour from their parents and peers – are we not just creating an elephant in mammoth’s clothing? It would, therefore, seem our resurrected animals would need some kind of training to survive in the wild, which may not be unlike the survival training reintroduced zoo animals already receive.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/67533/original/image-20141217-31049-1ijea2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/67533/original/image-20141217-31049-1ijea2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=377&fit=crop&dpr=1 600w, https://images.theconversation.com/files/67533/original/image-20141217-31049-1ijea2f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=377&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/67533/original/image-20141217-31049-1ijea2f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=377&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/67533/original/image-20141217-31049-1ijea2f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=473&fit=crop&dpr=1 754w, https://images.theconversation.com/files/67533/original/image-20141217-31049-1ijea2f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=473&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/67533/original/image-20141217-31049-1ijea2f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=473&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Benjamin, pictured here in 1933, may have been the last of the thylacines.</span>
<span class="attribution"><a class="source" href="http://en.wikipedia.org/wiki/File:%22Benjamin%22.jpg">Wiki</a></span>
</figcaption>
</figure>
<p>If a species was successfully reintroduced and its population grew to previous levels it would have a major ecological impact. The animals which have occupied its ecological space may find themselves squeezed out. Governments would, rightly, be very cautious about the reintroduction of such animals.</p>
<h2>Show me the money</h2>
<p>Given the limited money available for wildlife conservation it’s not clear that the expense of bringing back the dodo makes sense. A simple utilitarianism would suggest not; the cost of resurrecting the dodo could be used to save many other living species from extinction. For example, it now appears that a cloning approach may be the only solution to save the northern white rhinoceros from extinction – there are now only <a href="http://www.dailytech.com/After+Coming+So+Close+to+Recovering+Northern+White+Rhino+is+Nearly+Extinct/article36997.htm">five individuals</a> left.</p>
<p>However society, thankfully, does not always run according to such utilitarian analyses. So perhaps the dodo will have its day – even if that is just living in a zoo. It may behave like a farmyard chicken but it would still be a powerful symbol for species conservation: I suspect some zoos would be shedding their giant pandas to go into dodos.</p>
<h2>Dead as a dodo</h2>
<p>But what kind of symbol would a living dodo be? It can no longer be the symbol of extinction; the <a href="http://www.biologicaldiversity.org/news/press_releases/2014/rubber-dodo-10-31-2014.html">Rubber Dodo Award</a> for people who have contributed most to species extinction would need to be renamed. It would be testimony to how far science has come and how far science can take us. </p>
<p>But this sense of scientific wonder isn’t always helpful. A living dodo would give out the wrong message to society and politicians – we can destroy anything we like and scientists will eventually find a way to fix it. This seems, for example, to be the hope with climate change.</p>
<p>As a species I think we need to accept responsibility for what we have done to this planet and not have blind faith that in the future scientists will fix all of our mistakes. We need to live with our mistakes and learn from them. It is for this reason I am not wishing for de-extinction.</p><img src="https://counter.theconversation.com/content/35457/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert John Young 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>
My wildlife friends and I often talk about what species we would bring back from extinction. I am torn between the dodo and the thylacine, also known as the Tasmanian tiger. This was once a speculative…
Robert John Young, Professor of Wildlife Conservation, University of Salford
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/16335
2013-07-30T23:04:04Z
2013-07-30T23:04:04Z
Produce mammoth stem cells, says creator of Dolly the sheep
<figure><img src="https://images.theconversation.com/files/28288/original/tnmkr6rt-1375120569.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">But where would I live?</span> <span class="attribution"><span class="source">Royal BC Museum</span></span></figcaption></figure><p>It is unlikely that a mammoth could be cloned in the way we created Dolly the sheep, as has been proposed following <a href="http://www.telegraph.co.uk/news/newsvideo/10090196/10000-year-old-mammoth-found-preserved-in-Siberian-frost.html">the discovery</a> of mammoth bones in northern Siberia. However, the idea prompts us to consider the feasibility of other avenues. Even if the Dolly method is not possible, there are other ways in which it would be biologically interesting to work with viable mammoth cells if they can be found. </p>
<p>In order for a Dolly-like clone to be born it is necessary to have females of a closely related species to provide unfertilised eggs, and, if cloned embryos are produced, to carry the pregnancies. Cloning depends on having two cells. One is an egg recovered from an animal around the time when usually she would be mated.</p>
<p>In reality there would be a need for not just one, but several hundred or even several thousand eggs to allow an opportunity to optimise the cloning techniques. The cloning procedure is very inefficient. After all, after several years of research with sheep eggs, Dolly was the only one to develop from 277 cloned embryos. In species in which research has continued, the typical success rate is still only around 5% at best.</p>
<h2>Elephant eggs</h2>
<p>In this case the suggestion is to use eggs from elephants. Because there is a danger of elephants becoming extinct it is clearly not appropriate to try to obtain 500 eggs from elephants. But there is an alternative. </p>
<p>There is a considerable similarity in the mechanisms that regulate function of the ovaries in different mammals. <a href="http://www.purdue.edu/uns/html4ever/1998/9811.Critser.elephant.html">It has been shown that</a> maturation of elephant eggs is stimulated if ovarian tissue from elephants is transplanted into mice. </p>
<p>In this way it might be possible to obtain a considerable number of elephant eggs over a period of time if ovarian tissue is obtained from elephants that die. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/28280/original/xrt2dvdh-1375114658.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/28280/original/xrt2dvdh-1375114658.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/28280/original/xrt2dvdh-1375114658.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/28280/original/xrt2dvdh-1375114658.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/28280/original/xrt2dvdh-1375114658.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/28280/original/xrt2dvdh-1375114658.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/28280/original/xrt2dvdh-1375114658.jpg?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">
<figcaption>
<span class="caption">‘Am I not woolly enough for you?’</span>
<span class="attribution"><span class="source">ShaneRounce.com</span></span>
</figcaption>
</figure>
<p>Cells from mammoths are required to provide the genetic information to control development. The suggestion is to recover cells from the marrow of bones emerging from the frozen north of Siberia. However, these cells will degenerate rapidly at the temperature of melting snow and ice. This means that cells in the bones may well become useless for this capacity as they thaw. </p>
<p>The chances of cells being viable would be increased if bones could be recovered from the lowest possible temperature rather than waiting until they emerge from snow. The cells can then be warmed rapidly. Alternatively, the nuclei could be transferred directly into eggs. </p>
<p>The very first stages of embryo development <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0039723">are controlled by proteins</a> that are in the egg when it is shed by the ovary. One for example has a critical role in cell division. Together these proteins have an extraordinary ability to repair damaged nuclei so it may not be strictly necessary for the cells to be viable. It would be best if the mammoth nucleus could be introduced into an egg immediately, by injection of the contents of the damaged cell into the egg.</p>
<p><a href="http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0002978">Research</a> in 2008 found that when nuclei from freeze-dried sheep cells were transferred into eggs, some of the cloned embryos developed for a few days, but not to term. This was a very clear indication of the ability of the egg to repair damaged nuclei. However, freeze-dried cells are likely to be more stable than those that have been frozen with liquid still present. In the case of the mammoth, the cells would likely be killed by large ice crystals formed from the liquid. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/28279/original/g5zk8k5t-1375114052.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/28279/original/g5zk8k5t-1375114052.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/28279/original/g5zk8k5t-1375114052.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/28279/original/g5zk8k5t-1375114052.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/28279/original/g5zk8k5t-1375114052.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/28279/original/g5zk8k5t-1375114052.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/28279/original/g5zk8k5t-1375114052.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">Surrogate mother?</span>
<span class="attribution"><span class="source">Richard Towell</span></span>
</figcaption>
</figure>
<p>Finally, if embryos that developed normally for a few days could be produced, they would have to be transferred to surrogate mothers to develop through pregnancy. Embryo transfer is only carried out routinely in fewer than a dozen species, and the elephant is not one of them. Success in embryo transfer depends upon introducing the embryo to a womb that is in a receptive state. The mechanisms that bring about this state in elephants are currently being defined by <a href="http://nationalzoo.si.edu/SCBI/ReproductiveScience/ElephantBreedRepro/EndocrineLabServices.cfm">research</a> in a number of zoos.</p>
<p>Taken together, it can be seen that there is biological uncertainty about the availability of viable cells, and that several complex techniques would have to be developed for cloning of mammoths to be successful. There is no guarantee that these techniques are even biologically possible. There may be unknown differences between species that would prevent the procedures that we developed in sheep being successful in mammoths.</p>
<h2>Mammoth stem cells</h2>
<p>An alternative ambition would be to try to use mammoth cells to produce <a href="https://theconversation.com/explainer-what-are-stem-cells-14391">stem cells</a>. In several different species it is possible simply by the introduction of four selected proteins to give adult cells the characteristics of embryo stem cells. The four factors give embryo stem cells their unique characteristics and <a href="http://www.ncbi.nlm.nih.gov/pubmed/16904174">were found</a> to be able to impose these characteristics on skin cells. This type of stem cell can be grown for very long periods in the laboratory while retaining the ability to form all of the tissues of the body. </p>
<p>They would provide extraordinary opportunities to compare mammoth cells with those of elephants. This knowledge would be of fundamental biological interest. It would enable us to begin to answer groundbreaking questions. What are the differences between the cells and tissues of these species? What are the similarities? The mammoth lived in a different climate, so was the metabolism of their cells different? Does this information cast any light on the cause of extinction of mammoths?</p>
<p>Stem cells of this type can also be induced to form gametes. If the cells were from a female, this might provide an alternative source of eggs for use in research, and perhaps in breeding, including the cloning of mammoths. </p>
<p>From a male, they would be sperm, and they might be able to fertilise eggs to produce a new mammoth embryo. It would be interesting to know if mammoth sperm could fertilise eggs of the elephant. If so, would the embryos develop to term to produce a hybrid animal? </p>
<p>Only a small proportion of mixed matings between species produces viable offspring, but the mule is one example and has been used by humans for centuries. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/28285/original/f2vcf3cc-1375118091.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/28285/original/f2vcf3cc-1375118091.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/28285/original/f2vcf3cc-1375118091.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/28285/original/f2vcf3cc-1375118091.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/28285/original/f2vcf3cc-1375118091.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=468&fit=crop&dpr=1 754w, https://images.theconversation.com/files/28285/original/f2vcf3cc-1375118091.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=468&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/28285/original/f2vcf3cc-1375118091.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=468&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Labrador-mammoth hybrid?</span>
<span class="attribution"><span class="source">PetsAdviser</span></span>
</figcaption>
</figure>
<p>In all of these discussions it is necessary to consider the <a href="https://theconversation.com/mammoth-cloning-the-ethics-16183">welfare</a> of the animals. Mammoths lived in cold climates, whereas their current relatives including potential surrogate mothers live in warmer regions. </p>
<p>It would be essential to provide mother and clone with the appropriate environment of temperature, moisture and diet. It would almost certainly be necessary to keep the animals in captivity, so it would be essential to provide as interesting an environment as possible. Ideally this should include other elephants, mammoths or hybrids to provide social interaction for the animal. </p>
<p>So while unlikely at present, the development of some form of mammoth creature or hybrid might be possible in the longer term, the research of which could lead to major biological discoveries and advances. </p>
<p>This is another area of biology where studies of stem cells would be very rewarding. In stem cell research rather than cloning there would also be fewer concerns over animal welfare, or the effect of the animal on the environment. All in all, research to produce mammoth stem cells would be the appropriate choice, and extraordinarily scientifically rewarding, should it be possible to find viable mammoth cells.</p><img src="https://counter.theconversation.com/content/16335/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The research to develop the method of cloning was supported by the following public agencies Roslin Institute, Biotechnology Biological sciences Research Council, European Union, Department of Trade and Industry, Ministry of Agriculture Fisheries and Food.
In addition funds were provided by Animal Biotechnology Cambridge and Geron Corporation of Menlo Park California. </span></em></p>
It is unlikely that a mammoth could be cloned in the way we created Dolly the sheep, as has been proposed following the discovery of mammoth bones in northern Siberia. However, the idea prompts us to consider…
Ian Wilmut, Emeritus Professor at the MRC Centre for Regenerative Medicine, The University of Edinburgh
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/16183
2013-07-24T13:39:48Z
2013-07-24T13:39:48Z
Mammoth cloning: the ethics
<figure><img src="https://images.theconversation.com/files/27929/original/3bhyws3c-1374592102.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">On the comeback trail?</span> <span class="attribution"><span class="source">flickr: London looks</span></span></figcaption></figure><p>The display of a frozen mammoth in Japan has again raised questions as to the possibility of creating a <a href="http://www.guardian.co.uk/science/2013/jul/14/wooly-mammoth-extinct-cloning-dna">live born clone of extinct animals</a>.</p>
<p>Theoretically, mammoths could be cloned by recovering, reconstructing or synthesizing viable mammoth DNA and injecting it into the egg cell of a modern elephant whose nuclear DNA has been removed; alternatively, mammoth genetic material could be introduced into an elephant genome in order to create a mammoth-elephant hybrid or chimera.</p>
<p>This raises an ethical question as to <em>whether</em> we should start the journey down one of these paths.</p>
<h2>Habitat disruption</h2>
<p>Some people worry about the match between an extinct clone or novel chimera and the modern natural habitat. Firstly, there are worries that introducing these new species could disrupt natural ecosystems, or the so-called “balance of nature”. This was one of the many ethical themes in the novel and film Jurassic Park. Perhaps extinct animals are dead for a good ecological reason, so to speak, and “unnaturally” re-introducing them, particularly those that vanished long ago, would be futile or even pose serious global risks to life on the planet. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/27930/original/dspqnxd2-1374592531.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/27930/original/dspqnxd2-1374592531.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/27930/original/dspqnxd2-1374592531.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/27930/original/dspqnxd2-1374592531.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/27930/original/dspqnxd2-1374592531.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/27930/original/dspqnxd2-1374592531.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/27930/original/dspqnxd2-1374592531.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">Dangerous intentions?</span>
<span class="attribution"><span class="source">flickr: Dave Catchpole</span></span>
</figcaption>
</figure>
<p>This is a common concern that should be addressed. Mammoths were widely around until 10,000 years ago, with some surviving until as recently as 4,000 years ago. Mammoths are thus not particularly ‘alien’ organisms from a modern ecological standpoint. They lived and evolved alongside much of the modern flora and fauna, including humans - who are, incidentally, likely responsible for their extinction. It is therefore highly unlikely that the introduction of a mammoth population would severely perturb natural ecosystems.</p>
<p>In any case, the extent to which there really is a “benevolent balance of nature” has been vigorously contested in biology. Food webs are often maintained despite significant fluctuations in extinction, invasion, migration, diversity, and energy pathways.</p>
<h2>Resurrecting an extinct animal</h2>
<p>A second concern regards the well-being of the cloned animal itself. Mammoths are social creatures, and if one or more of them were produced and kept in an artificial environment, such as a zoo, or were subject to disturbing experimental conditions, it could be distressing and painful for them. This concern would be even greater if we were re-creating extinct species with even higher cognitive functions, such as Neanderthals or human-chimp chimeras – something that is also theoretically possible. </p>
<p>The <a href="http://blog.practicalethics.ox.ac.uk/2013/01/back-to-the-future-the-ethics-of-cloning-neanderthals-and-creating-genetically-modified-animals/">critical ethical issue</a> in re-creating extinct species, or in creating new kinds of animals, is to first determine through careful scientific study what is in their interests and to ensure that they live good lives in the world in which they are created. Creating favourable conditions for extinct animals or novel chimeras might require modifying or creating new habitats in which they can flourish.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/27932/original/9zz2ptf2-1374592914.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/27932/original/9zz2ptf2-1374592914.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/27932/original/9zz2ptf2-1374592914.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/27932/original/9zz2ptf2-1374592914.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/27932/original/9zz2ptf2-1374592914.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/27932/original/9zz2ptf2-1374592914.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/27932/original/9zz2ptf2-1374592914.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">Not quite favourable.</span>
<span class="attribution"><span class="source">flickr: JeanninePC</span></span>
</figcaption>
</figure>
<p>This point is crucial. We cannot always know in advance whether the introduction of a new species will be good or bad for the animal introduced, or for other animals, including humans, communities and ecosystems. Once a new animal is created, it should not be introduced into the wild or into captivity until it is humanely studied to evaluate its own interests, and the threat it might pose to others. </p>
<p>However, if we are confident that a cognitively sophisticated organism, such as a mammoth, would lead a good life, this may provide moral reasons to create it — whether or not that animal is a clone of a member of an extinct lineage.</p>
<h2>But why bother?</h2>
<p>Richard Dawkins recently tweeted,</p>
<blockquote><p>Why bother (to clone mammoths)? Why bother? Why bother to go on living? Why not just stop breathing if you are that incurious?</p>— Richard Dawkins (@RichardDawkins) <a href="https://twitter.com/RichardDawkins/statuses/356694382671441920">July 15, 2013</a></blockquote>
<p>But it is not just curiosity that drives the imperative to introduce extinct, novel or threatened species. We now have the power not only to obliterate life from the planet, but also to protect and manage it. </p>
<p>We should decide what kind of life there should be. We should invest in technologies that allow us to maintain biological diversity and perhaps even increase it. Some might even argue that humans have a particular moral obligation to re-introduce species whose extinction they caused, either directly, as is likely in the case of the mammoth, or indirectly, as a result of global climatic disruption.</p>
<p>The value of re-creating mammoths might consist largely in satisfying intrinsic human curiosity. But, creating or re-creating some kinds of life forms may also be of great instrumental value to human beings, say in blocking the emergence of pathogens, or in helping to ensure the continued existence of life on the planet. What initially seems like a curiosity actually prompts a deep question about the role of humans in directing the future course of life on this planet.</p>
<p>Up until this point, human influence on the world has largely been destructive. But we are now entering a phase where our influence can be constructive. We can now preserve species not merely by conservation of the environment, but also through the use of genetic engineering, synthetic biology, and other reproductive technologies.</p>
<h2>Is biological intervention “playing God”?</h2>
<p>Many people believe that environmental interventions are preferable to and should be prioritized over biological ones, but we think <a href="http://books.google.co.uk/books?id=Eld5U-PIsrcC&printsec=frontcover&dq=Unfit+for+the+Future:+The+Need+for+Moral+Enhancement&hl=en&sa=X&ei=n4DuUdDHCaqL7Ab-ooHIDg&ved=0CDEQ6AEwAA#v=onepage&q=Unfit%20for%20the%20Future%3A%20The%20Need%20for%20Moral%20Enhancement&f=false">and have argued</a> that so urgent are our problems, we must explore all options, including using knowledge of the biological sciences to possibly deal with social or environmental problems. There are four ways to achieve any goal, be it human survival, species diversity, or global security: modify the environment, society, human psychology or biology. All options should be explored.</p>
<p>Some object to “deep” human intervention in nature, like the cloning of extinct organisms or the creation of chimeric organisms, on the grounds that such interventions amount to “playing God”. Since humans intervene in nature all the time and for good moral reasons, for example medicine, there cannot be something inherently morally problematic about such interventions. The focus should instead be on the types of harms that we identified above.</p>
<p>There has been <a href="http://www.ncbi.nlm.nih.gov/pubmed/23810562">much discussion</a> about whether synthetic biology could really create artificial life. A much more profound and pressing ethical question asks what <em>kinds</em> of life forms there should be. It is now within our power to decide.</p><img src="https://counter.theconversation.com/content/16183/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julian Savulescu receives relevant funding from the Uehiro Foundation on Ethics and Education (Oxford Uehiro Centre for Practical Ethics) and has received relevant funding from the Oxford Martin School (Institute for Science and Ethics).</span></em></p><p class="fine-print"><em><span>Russell Powell 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>
The display of a frozen mammoth in Japan has again raised questions as to the possibility of creating a live born clone of extinct animals. Theoretically, mammoths could be cloned by recovering, reconstructing…
Julian Savulescu, Sir Louis Matheson Distinguished Visiting Professor, Monash University
Russell Powell, Assistant Professor of Philosophy, Boston University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/4168
2011-11-08T19:41:31Z
2011-11-08T19:41:31Z
Did climate cause the extinction of the Ice Age megafauna?
<figure><img src="https://images.theconversation.com/files/5270/original/Picture_Beringia_GeorgeTeichmann.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The demise of the woolly mammoth could teach us much about our effect on other species.</span> <span class="attribution"><span class="source">George Teichmann</span></span></figcaption></figure><p>When we think of the last 50,000 years of prehistory, particularly the “Ice Age”, extinct species such as the <a href="http://www.bbc.co.uk/nature/life/Woolly_mammoth">woolly mammoth</a> and <a href="http://www.rhinos-irf.org/woolly/">woolly rhinoceros</a> often spring to mind. </p>
<p>Did humans bring about the extinction of these large animals (megafauna)? Or did they succumb to the impacts of a changing climate? And how did other megafauna, such as the elephant and reindeer, manage to survive?</p>
<p>These questions have troubled biologists for the past two centuries. They have also been the subject of heated debate in Australia, which has lost impressive species such as the <a href="http://australianmuseum.net.au/Diprotodon-optatum">diprotodon</a> (a hippo-sized wombat) and giant versions of modern-day marsupials.</p>
<p>For many of the species that went extinct in the past few hundred years – including the <a href="http://terranature.org/moa.htm">New Zealand moa</a> and the <a href="http://www.bbc.co.uk/nature/life/Elephant_bird">Malagasy elephant birds</a> – there is overwhelming evidence that human activity caused their demise. </p>
<p>In other parts of the world, megafaunal extinctions roughly coincided with the arrival of humans. But coincidence is not proof of causation. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/5276/original/Moa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/5276/original/Moa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=849&fit=crop&dpr=1 600w, https://images.theconversation.com/files/5276/original/Moa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=849&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/5276/original/Moa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=849&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/5276/original/Moa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1067&fit=crop&dpr=1 754w, https://images.theconversation.com/files/5276/original/Moa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1067&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/5276/original/Moa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1067&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Moa was a large flightless bird endemic to New Zealand.</span>
</figcaption>
</figure>
<p>The disagreement has persisted because researchers have had differing interpretations of scant evidence. Many of the megafaunal species went extinct long ago, leaving few traces in the fossil and archaeological records. </p>
<p>Thanks to the huge progress in methods for genetic analysis, it is now possible to look at populations of extinct animals by studying DNA from ancient specimens. This DNA contains signatures of past changes in population size. These can be used to look at ancient populations and to see how they changed through time.</p>
<h2>Bringing the evidence together</h2>
<p><a href="http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10574.html">In an article recently published in Nature</a>, my colleagues and I studied megafaunal extinctions by focusing on six species. These included the woolly mammoth, woolly rhinoceros, steppe bison, muskox, wild horse, and reindeer.</p>
<p>We chose to look at the Northern Hemisphere, where the permafrost has preserved huge numbers of specimens for us to analyse. </p>
<p>Our team of geneticists, archaeologists, and zoologists assembled the largest data set of its kind. The study involved nearly 10,000 <a href="http://en.wikipedia.org/wiki/Radiocarbon_dating">radiocarbon dates</a> and over 800 DNA sequences. </p>
<p>Apart from reconstructing the populations of the six species, we were able to evaluate the likely effects of humans by estimating their geographical overlap with the megafauna. The interaction between humans and the six species was assessed by the presence of megafaunal remains in archaeological sites.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/5275/original/diprotodon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/5275/original/diprotodon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=354&fit=crop&dpr=1 600w, https://images.theconversation.com/files/5275/original/diprotodon.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=354&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/5275/original/diprotodon.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=354&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/5275/original/diprotodon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=445&fit=crop&dpr=1 754w, https://images.theconversation.com/files/5275/original/diprotodon.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=445&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/5275/original/diprotodon.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=445&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The three-metre-long Diprotodon went extinct roughly 46,000 years ago.</span>
</figcaption>
</figure> <p></p>
<p>Using estimates of the timing of changes in populations, we were able to examine the impact of changes in climate. For example, the population size of North American bison experienced a drastic decline during the height of the last Ice Age, when their habitat would have been greatly reduced.</p>
<p>We found that the decline of the woolly rhinoceros and musk ox could be explained entirely by changes in climate. It is likely that human expansion contributed to the demise of the steppe bison and wild horse – the two most common megafaunal species found in archaeological sites.</p>
<p>The reindeer has thrived to the modern day, but we could not find a clear cause for the extinction of the woolly mammoth.</p>
<p>Overall, our study shows the six species varied considerably in their responses to human impacts and changing climate. This suggests the causes of extinction can be complex and probably differ among species.</p>
<h2>Megafaunal extinctions in Australia</h2>
<p>It is unlikely we will ever be able to conduct such a comprehensive study on the extinctions in Australia. Good specimens are scarce and DNA degrades quickly in Australian conditions. </p>
<p><figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/5274/original/elephant_bird.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/5274/original/elephant_bird.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=799&fit=crop&dpr=1 600w, https://images.theconversation.com/files/5274/original/elephant_bird.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=799&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/5274/original/elephant_bird.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=799&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/5274/original/elephant_bird.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1004&fit=crop&dpr=1 754w, https://images.theconversation.com/files/5274/original/elephant_bird.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1004&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/5274/original/elephant_bird.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1004&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Before extinction, the elephant bird lived only in Madagascar.</span>
</figcaption>
</figure>
</p><p>It has been difficult to place reliable dates on the megafaunal extinctions in Australia. This is because human colonisation and many of the extinction events occurred around 50,000 years ago, which is at the upper limit of radiocarbon dating. </p>
<p>The arrival of humans signalled a drastic change in the Australian environment, not just because of hunting, but also because of the extensive use of fire. This would have altered vegetation and the distributions of habitats. </p>
<p>Our chances of determining the causes of these extinctions will improve with progress in dating methods and ancient DNA analysis. Further refinement of the timing of human arrival in Australia will also be helpful.</p>
<h2>Lessons for the future</h2>
<p>Humans are now modifying the environment and the atmosphere at an alarming pace. This raises grave concerns about the future of the planet’s biodiversity. Many of the present-day megafaunal species are under threat and require careful management. </p>
<p>If there are any lessons to be learnt from our study of the megafaunal extinctions, it is that different species respond differently to the pressures of human hunting and encroachment, habitat redistribution, and changing climate.</p>
<p>This presents a challenge for conservation efforts because it can be difficult to predict the course of modern animal populations.</p><img src="https://counter.theconversation.com/content/4168/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Ho receives funding from the Australian Research Council.</span></em></p>
When we think of the last 50,000 years of prehistory, particularly the “Ice Age”, extinct species such as the woolly mammoth and woolly rhinoceros often spring to mind. Did humans bring about the extinction…
Simon Ho, Associate Professor, School of Biological Science, University of Sydney
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