tag:theconversation.com,2011:/ca/topics/early-ancestors-20087/articlesEarly ancestors – The Conversation2017-10-12T13:46:01Ztag:theconversation.com,2011:article/847162017-10-12T13:46:01Z2017-10-12T13:46:01ZAncient DNA increases the genetic time depth of modern humans<figure><img src="https://images.theconversation.com/files/189965/original/file-20171012-31375-hmz15a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tapping into ancient DNA can help us understand ancient humans' movements and lives.</span> <span class="attribution"><a class="source" href="https://www.google.co.za/search?q=DNA&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjdmrr14efWAhVIChoKHQ4qB2IQ_AUICygC&biw=1522&bih=708#imgrc=GOr_O-uj32HSEM">Illustration: Marlize Lombard, Maryna Steyn and Anders Högberg</a></span></figcaption></figure><p>It’s been about 2000 years since a young boy died on what is today a beach in South Africa’s KwaZulu-Natal province. In the 1960s the child’s remains were exposed to wind and rain. It was carefully excavated and taken to the museum in Durban and later to Pietermaritzburg. Over the past four years I have worked with a team of researchers who reconstructed the DNA of the boy from Ballito Bay and other ancient individuals, and what we’ve <a href="http://science.sciencemag.org/content/early/2017/09/27/science.aao6266.long">discovered</a> changed what we know about deep human history.</p>
<p>The boy lived about 2000 years ago, which helped us to recalculate the time at which humans like us – <em>Homo sapiens</em> – first split or branched from archaic or pre-modern human groups to between 350 000 and 260 000 years ago.</p>
<p>Previously, it was thought that we emerged just a little less than 200 000 years ago. This was mostly based on the shape of fossil skulls found in Ethiopia, and on earlier work on the DNA of people currently living in southern Africa, such as Khoe-San groups. </p>
<p>Then, earlier in 2017, a <a href="http://www.sciencemag.org/news/2017/06/world-s-oldest-homo-sapiens-fossils-found-morocco">skull from Morocco</a> that looks like a combination of us and older human groups was dated to about 300 000 years ago. This age also overlaps with that of <a href="http://news.nationalgeographic.com/2017/05/homo-naledi-human-evolution-science/"><em>Homo naledi</em></a> in South Africa.</p>
<p>Our deeper genetic estimate for the origin of modern humans further tallies with the ages of two other southern African archaeological finds, the <a href="http://showme.co.za/tourism/florisbad-museum-and-research-centre-soutpan/">Florisbad skull</a> and <a href="https://www.ncbi.nlm.nih.gov/pubmed/8599389">Hoedjiespunt fossils</a>. If we take all the DNA, archaeological and fossil evidence together, the period roughly between about 200 000 and 350 000 years ago is becoming increasingly interesting for exploring our origins. </p>
<p>Collectively, this research shows that humans might have originated from several regions in Africa instead of just one, with different groups interacting with each other through time and across the landscape. We do not know exactly how or where – yet. But work like ours helps to fill gaps and highlight interesting new questions. For example, by pushing back our genetic origins it is now necessary to revisit interpretations of “what is human” in the fossil record.</p>
<h2>Digging into DNA</h2>
<p>South Africa has a fascinating archaeological record, with a Stone Age spanning more than 2 million years. But archaeology is not only about stones and bones: it is mainly about the people of the past.</p>
<p>So how do we get from the stones and the bones to the people? One way is through DNA. The last decade saw remarkable development in the technology and methods to understand ancient human DNA. As an archaeologist I became fascinated by what these approaches could tell us about our human origins in Africa, and started working with colleagues in <a href="https://h3africa.org/component/contact/contact/15-other/37-dr-himla-soodyall">South Africa</a> and <a href="http://katalog.uu.se/profile/?id=N9-1616">Sweden</a> who are geneticists associated with a <a href="http://www.iob.uu.se/research/evolution-and-development/jakobsson?languageId=1">laboratory</a> in Uppsala specialising in ancient human DNA. </p>
<p>Some of my previous research has focused on Stone Age sites in KwaZulu-Natal, so that it made sense to focus on ancient DNA from this province. The team at Uppsala’s laboratory, assembled experts to do the extraction, analysis and interpretation of the results, resulting in this newest research.</p>
<p>We were able to reconstruct the full genome of the Ballito Bay child together with six other individuals from KwaZulu-Natal. The remains of one adult male also come from Ballito Bay; those of an adult female were found on the beach at Doonside, further south. Together with the boy, they are associated with the Stone Age more than 2000 years ago in South Africa. Genetically, they are related to <a href="http://www.san.org.za/history.php">San groups</a> who were on the landscape before herders from East Africa came in to live among them and formed local herding groups, historically known as the <a href="http://www.sahistory.org.za/article/khoikhoi">Khoe or Khoikhoi</a>.</p>
<p>The remains of the four other individuals are from contexts that archaeologists associate with the <a href="http://www.sahistory.org.za/article/iron-age-kingdoms-southern-africa">Iron Age</a>. These were farmers who came into southern Africa from West Africa, possibly through what is today Angola. </p>
<p>All four of these individuals were found not on the coast, but in KwaZulu-Natal’s inland areas. Interestingly, these Iron Age individuals had gene variations to protect them against <a href="https://www.youtube.com/watch?v=j9_Vq78Ljzc">malaria</a> and sleeping sickness. We didn’t find similar variations among the Stone Age individuals. This shows that the Iron Age individuals lived or moved through areas in Africa long enough to build resistance against these diseases, whereas those from the Stone Age probably did not.</p>
<h2>Building our understanding</h2>
<p>This is an important addition to our understanding of human history.</p>
<p>Cumulatively, the fossil, ancient DNA and archaeological records indicate that the transition from archaic to modern humans was older than previously thought, and probably did not occur in one place in Africa. Instead there might have been <a href="https://vimeo.com/19797501">gene flow</a> between groups from, eastern, southern and northern Africa, who all potentially played a role in our common human history.</p>
<p>Reconstructing the full genomes of human remains even older than 2000 years will help us to understand the relationships between the different groups that roamed the African landscape during ancient times.</p><img src="https://counter.theconversation.com/content/84716/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marlize Lombard receives funding from the African Origins Platform of the National Research Foundation of South Africa. </span></em></p>Archaeology is not only about stones and bones: it is mainly about the people of the past. DNA is one way to get from the stones and the bones to the people and their stories.Marlize Lombard, Professor with Research Focus in Stone Age Archaeology; Director, Centre for Anthropological Research in the Department of Anthropology and Development Studies, University of JohannesburgLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/851862017-10-09T17:25:22Z2017-10-09T17:25:22ZAncient DNA unearths fascinating secrets. But what about the ethics?<figure><img src="https://images.theconversation.com/files/189296/original/file-20171008-25749-1f3e745.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Research of ancient DNA has tended to ignore previous studies about the bones themselves.</span> <span class="attribution"><span class="source">Reuters/Siphiwe Sibeko</span></span></figcaption></figure><p>Ancient DNA is starting to reveal the secrets of how people emerged from, moved into or moved around Africa. Human skeletons from <a href="https://academic.oup.com/gbe/article-lookup/doi/10.1093/gbe/evu202">Saldanha Bay</a> in South Africa’s Western Cape province, <a href="http://science.sciencemag.org/content/early/2017/09/27/science.aao6266.long">Ballito Bay</a> in its KwaZulu-Natal province and Mota Cave in <a href="http://science.sciencemag.org/content/350/6262/820">Ethiopia</a>; Tanzania and now <a href="http://www.sciencedirect.com/science/article/pii/S0092867417310085?via%3Dihub">Malawi</a> have been analysed and the results recently published.</p>
<p>I am part of a team working on a whole series of skeletons from the Later Stone site of Faraoskop in the Western Cape. We are trying to find both <a href="https://ghr.nlm.nih.gov/primer/basics/mtdna">mitochondrial</a> and nuclear DNA samples to work out relationships between individuals in what may have been a case of mass killing some 2000 years ago.</p>
<p>This rush of projects has presented the curators of archaeological skeletons with ethical issues because the research requires the destruction of human bone. </p>
<p>There are four central problems that concern me and that have been echoed in my private correspondence with various colleagues: competition between labs for samples; the danger of parachute research (foreign researchers who drop in, gather data and go home again); the disconnection between the study of bones and genetics; and laboratory methodologies and comparative data.</p>
<h2>The challenges</h2>
<p><strong>Competition for samples:</strong> This has become a very real problem. At least five labs have been processing archaeological skeletons from South Africa. Back in May 2014, I made a list of all ancient DNA projects on South African specimens that had, up to that point, been proposed or were in action. I counted 13, though not all of these have taken place. </p>
<p>In some cases permission to sample has been refused. One reason for refusal is that the project is simply an attempt to analyse skeletons because they are old and available. This sort of analysis may be good for the laboratory concerned, but it is just plain bad science and is perilously close to “mining” of bone specimens from museums. </p>
<p>Much of the competition for samples is publication driven with labs chasing the next paper in Nature or other high-impact journals. This is obviously important as it can drive funding for labs or promotions for their denizens. </p>
<p><strong>Parachute research:</strong> It’s very easy to do sampling in this kind of research. All that’s required is a nubbin of bone, and in most cases that is sent out of the country for analysis to happen elsewhere. So how should South African researchers fit in? </p>
<p>For a number of years there was an active resistance to setting up a South African lab in the belief that it was too expensive and funding would be better spent on projects that have a more direct benefit to the country’s previously disadvantaged people. That attitude is now changing in some quarters and I have heard talk of setting up labs in Cape Town, Johannesburg and Pretoria. How would such labs link to overseas institutions? </p>
<p><strong>Genes versus bones:</strong> There has been a definite tendency for genetic research to ignore information gathered in <a href="https://doi.org/10.1080/00359190509520487">previous studies</a> of the bones of the skeletons themselves.</p>
<p>Ancient DNA research, like genetic research on living peoples, has been focused on tracing back lineage lines through mitochondrial, Y-chromosome or, very recently, nuclear DNA. All that has been required is a tiny fragment of bone that can yield DNA. But can such studies give us a true picture of the past? </p>
<p>The answer is “yes” in terms of lineage, but “no” in terms of life experience and adaptation. This issue is important because the first choice in sampling should be from as complete a skeleton as possible so that genetic and osteological data – that is, information about bones – can be compared. </p>
<p>Perhaps the most extreme example of this problem is the construction of the human ancestor known as the “<a href="https://genographic.nationalgeographic.com/denisovan/">Denisovans</a>”. Much has been written about these distant ancestors’ genetics. But all of it has been based on one finger bone and three teeth from one site. We actually know nothing about these people except for their genetic shadow. The forensic anthropologist in me screams that I must have a body before making any conclusions. The same goes for the discussion of people from the comparatively recent African past. </p>
<p><strong>Comparative data:</strong> As a non-geneticist, it did not cross my mind that different labs might produce different DNA results. Some years ago I had my own Y-chromosome and mitochondrial DNA analysed. The results were fascinating, but I was extremely surprised to discover that if I sent the same samples to different DNA heritage laboratories I could get different results. </p>
<p>It is not the analysis itself that is different, but the reference samples that are chosen for comparison. This can be resolved as the analysed samples become more numerous – as long as the different labs share their results – but I have recently discovered that not all labs are the same when it comes to piecing together long strands of nuclear DNA from the fragments discovered in the process of extracting ancient DNA from bones. </p>
<p>The processing methods are not interchangeable and there are at least two different methodologies that produce different success rates. This means it is possible that results from different labs may not be comparable. This would make the competition between labs even more intense and might even result in multiple requests for samples from the same skeleton. </p>
<h2>Knowledge about African heritage</h2>
<p>Ultimately, the most important issue is that African scientists need to be part of the research and African descendant communities need to be able to access the information discovered about their ancestors. </p>
<p>We need to ensure that both training and jobs in ancient DNA research are available in African countries and that publications are submitted to local scientific and museum journals. This research is not about the next promotion for the lab scientists. It is about building the knowledge base of our African heritage. </p>
<p><em>This article has been adapted from <a href="http://www.sajs.co.za/system/tdf/publications/pdf/SAJS-113-9-10_Morris_NewsViews.pdf?file=1&type=node&id=35847&force=">a piece</a> which originally appeared in the South African Journal of Science.</em></p><img src="https://counter.theconversation.com/content/85186/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alan G Morris receives funding from South African NRF.</span></em></p>A rush of ancient DNA projects in Africa has presented the curators of archaeological skeletons with ethical issues because research requires the destruction of human bone.Alan G Morris, Professor of Biological Anthropology, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/839112017-09-18T16:19:50Z2017-09-18T16:19:50ZVirtual reality breathes new life into African fossils, art and artefacts<figure><img src="https://images.theconversation.com/files/185670/original/file-20170912-10821-wdtqno.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This picture of a reconstruction of a hominin skull is one of a variety of multimedia that can be experienced in the Origins Virtual Reality experience.</span> <span class="attribution"><span class="source">Wits University</span></span></figcaption></figure><p>Digital technology has become an integral part of our everyday lives. So it was only a matter of time before the ways people interact with the past and ancient artefacts in museum settings became digital, too. </p>
<p>The problem is that technology can be extremely expensive. Many museums just don’t have the funding to obtain, develop and maintain fancy devices or interactive digital gadgets. Some big European and North American museums, which receive millions of visitors each year, have been able to afford virtual reality (VR) and various other digital technologies. These are an appealing and popular element of the visitor experience. </p>
<p>For example, you can tour the <a href="http://blog.britishmuseum.org/new-virtual-reality-tour-with-oculus/">British Museum</a> in London using VR. Visitors to the <a href="https://americanart.si.edu/">Smithsonian American Art Museum</a> in Washington, DC can download an app to experience one of the exhibits in VR. </p>
<p>More digital avenues are being added to South Africa’s museums – and now the country has its first full VR exhibit. It will launch at the <a href="https://www.wits.ac.za/origins/">Origins Centre</a> at the University of the Witwatersrand in Johannesburg on 25 September and will take visitors on a journey through hundreds of thousands of years of human history, art and innovation. <a href="http://wits.academia.edu/TammyHodgskiss">I am a</a> Middle Stone Age archaeologist and ochre specialist, and have been part of the team putting the exhibit together over the past four months. </p>
<p>Along the way, we’ve had to work out how to marry facts, interpretations, stories and technology. This hasn’t always been easy, but there have been a number of lessons along the way: most crucially, about the value of collaborative, interdisciplinary work to bring science to life.</p>
<h2>Getting started</h2>
<p>Steven Sack, the director of the Origins Centre and Professor Barry Dwolatzky, who runs the university’s <a href="http://www.tshimologong.joburg/">Tshimologong Digital Precinct</a>, were the exhibit’s initial champions. The precinct is a technology hub. Dwolatzky was so enthusiastic about the idea of VR at the Origins Centre that he personally donated money towards it. Armed with this and a grant from the <a href="http://www.nihss.ac.za/">National Institute of Humanities and Social Sciences</a>, we got started.</p>
<p>The next step was to develop VR hardware – headsets loaded in the content we went on to produce. For this, we had to look beyond academia and bring in a team from <a href="http://altreality.co.za/">Alt-Reality</a>, a company in Johannesburg. </p>
<p>My role was to provide guidance on my own areas of expertise, and to act as a link between the Origins Centre and Professor Chris Henshilwood, for whom I work at the university’s <a href="https://www.wits.ac.za/esi/">Evolutionary Studies Institute</a>. It was one of the institutes that provided a great deal of content for the VR exhibit.</p>
<p>Lara Mallen, a rock art specialist who was the curator at the Origins Centre, was a crucial part of the project: her knowledge of the centre’s displays and her intricate understanding of the rock art was vital in developing the content. </p>
<p>I bugged many of my peers in the Evolutionary Studies Institute, <a href="https://www.wits.ac.za/rockart/">Rock Art Research Institute</a> and <a href="https://www.wits.ac.za/gaes/">School of Geography, Archaeology and Environmental Studies</a> at Wits University as well as researchers at other institutions for their opinions and images. We also sourced video and digital content from their research that we could include in the VR exhibit. They were all intrigued and excited by the chance to share their work in a totally new, different form.</p>
<p>Then came the balancing act: what would work well in VR, how much content could we have and what was missing. It was a very organic and ever-changing process. We continually revised, cut and added content. </p>
<p>The visitor can chose what they want to see and what they want to learn more about. They can see (and hear) how people made stone tools and ground ochre 100,000 years ago, or they can be transported into a painted rock shelter while also being able to see the individual images right up close.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/185983/original/file-20170914-8975-kg5pz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185983/original/file-20170914-8975-kg5pz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=633&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185983/original/file-20170914-8975-kg5pz9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=633&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185983/original/file-20170914-8975-kg5pz9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=633&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185983/original/file-20170914-8975-kg5pz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=795&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185983/original/file-20170914-8975-kg5pz9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=795&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185983/original/file-20170914-8975-kg5pz9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=795&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An ochre processing toolkit from the Blombos caves. VR allows visitors to see how the process worked.</span>
<span class="attribution"><span class="source">C Henshilwood</span></span>
</figcaption>
</figure>
<h2>Telling stories in new ways</h2>
<p>As an academic I wanted to make sure that we presented a factual yet exciting summary of the Origin Centre’s content. That wasn’t at all straightforward. </p>
<p>We had to decide what stories we chose to tell, how we wanted to tell them – and whether our interpretations were correct. Bringing the past into a digital space creates so much more overt space for interpretation and different narratives. Traditional museum panels explain what an object is and how old it is. The VR actually shows how it worked and the process archaeologists have used to find that out.</p>
<p>One of the most valuable aspects of this project has been the opportunity to diversify traditional narratives around archaeology. Women and children have been somewhat neglected in archaeological interpretations, especially since in the past most histories were written by (white) men. This has tended to present a simplistic picture of prehistoric societies: men hunting, women gathering.</p>
<p>But there was more to it than that. Stone tools had to be made; poison was collected on use on the tips. Fires needed to be built and ochre ground to create paint for ritual. VR gives more space to explain the answers and explore the nuances of prehistoric societies.</p>
<p>Collaborating with a team of researchers of different ages, backgrounds and genders means a more unbiased picture of the past can be created. The VR content allows anyone to interact with the artefacts – female, male, young and old. They can immerse themselves in it and draw their own conclusions. </p>
<p>The digital experience might also appeal more to younger people and hopefully bring more young visitors into the museum. But it’s accessible, enlightening and informative and older people will enjoy it too.</p>
<h2>Collaboration is exciting</h2>
<p>As a scientist, I think these kinds of interactive museum displays are vital in aiding deeper understanding and interest in a topic. The same applies to archaeological research. </p>
<p>Being able to manipulate or reconstruct artefacts and use them helps us to understand how and why they were used or created. Being in the team that has conceptualised and created the Origins Centre’s VR content has reminded me that collaborative and interdisciplinary work – even though sometimes tricky to start – can be so fulfilling and revolutionary.</p><img src="https://counter.theconversation.com/content/83911/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tammy Hodgskiss 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>Bringing the past into a digital space creates so much more overt space for interpretation and different narratives.Tammy Hodgskiss, Research Associate, Evolutionary Studies Institute, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/782802017-05-25T13:35:41Z2017-05-25T13:35:41ZThere’s not enough evidence to back the claim that humans originated in Europe<figure><img src="https://images.theconversation.com/files/170798/original/file-20170524-31352-14imfyh.jpg?ixlib=rb-1.1.0&rect=2%2C2%2C1381%2C971&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The fossil remains which have caused all the consternation.</span> <span class="attribution"><span class="source">Jochen Fuss, Nikolai Spassov, David R. Begun, Madelaine Böhme/via Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>Africa is not the cradle of humankind: that’s the claim by a group of scientists who’ve <a href="https://phys.org/news/2017-05-scientists-million-year-old-pre-human-balkans.html">just published</a> what they describe as evidence of pre-human remains found in Eastern Europe (Greece and Bulgaria). The fossils in question belong to Graecopithecus freybergi, and are a little more than seven million years old. This would make them the world’s oldest hominin fossils.</em> </p>
<p><em>It would also re-root the human evolutionary tree in Eastern Europe, away from Africa. This runs counter to a great deal of evidence which suggests that humans originated in Africa.</em></p>
<p><em>Dr Julien Benoit, a vertebrate palaeontologist and palaeobiologist who has worked extensively on the African continent and was not part of the European research team, chatted to The Conversation Africa about the findings.</em></p>
<p><strong>This new research suggests that Greece, not Africa, should be calling itself the cradle of humankind. Do you think that’s accurate?</strong></p>
<p>Extraordinary claims need extraordinary evidence to support them. The African origin of humankind (<a href="http://www.sciencedirect.com/science/article/pii/S0047248416300100">Hominini</a>) is currently supported by two really important elements.</p>
<p>Firstly, <a href="https://medium.com/@johnhawks/how-much-evidence-have-scientists-found-for-human-evolution-355801dfd35c">thousands</a> of hominin fossils have been found on African soil since the first fossil African hominin, <em>Australopithecus africanus</em>, was discovered in South Africa in 1924. </p>
<p>Nearly a century of fossil findings has followed, chronicling the complete evolution of hominin on African soil. These fossils range from the <em>Sahelanthropus</em>, which lived between six and seven million years ago in what is today Chad, to the earliest <em>Homo sapiens</em> from east Africa. </p>
<p>Secondly, our closest ape relatives, the Chimpanzees and the Gorilla are also <a href="http://www.nature.com/nature/journal/v448/n7156/full/nature06113.html">from Africa</a>. Our last common ancestors lived somewhere between eight and 12 million years ago, which strongly suggests that the origin of humankind is deeply rooted in Africa. This leave little room for a putative European origin.</p>
<p>Any study that counters this consensus would have to provide very strong evidence and perfect methodology to support its claim. In my opinion, this article doesn’t meet those criteria.</p>
<p><strong>Why not?</strong></p>
<p>For starters, the material isn’t well preserved. It consists mostly of a jaw with no complete teeth preserved. That’s a problem because the teeth’s anatomical characteristics are the most important element when classifying any primate, including humans.</p>
<p>The authors claim that the jaw’s fourth premolar root is similar to that of a hominin’s. This is not a character that is conventionally used in palaeoanthropology, especially because not all hominins have similar tooth roots. This character is rather variable – and the authors go on to acknowledge this – so it’s unreliable for classification.</p>
<p>They also argue that the small size of the incomplete canine tooth (as suggested by the size of its root) would put this fossil close to hominin ancestry. This is based on the assumption that hominins are the only apes with small canines. This, again, is not true. In Europe, where apes have a very rich fossil record, there’s an ape called <a href="http://www.smithsonianmag.com/science-nature/human-evolutions-cookie-monster-oreopithecus-1657956/">Oreopithecus</a> which has small canines but is not related to humans at all. </p>
<p>This is an example of independent, parallel evolution: when one species evolves similarities to another without being related to it. For instance, dolphins look like fish, but <a href="http://oceanservice.noaa.gov/facts/dolphins.html">they’re not</a>. This is probably the same thing for <em>Graecopithecus</em> and hominins.</p>
<p>I agree with many of my <a href="http://johnhawks.net/weblog/fossils/miocene/graecopithecus/graecopithecus-fuss-2017.html">colleagues</a>, who think that this new jaw represents an Ape species that is not related to humans. It might belong to a species like <em>Oreopithecus</em>, which evolved human-like features – such as the fusion of the fourth premolar roots and small canines – in parallel to our lineage. </p>
<p>Finally, the study is lacking a phylogenetic analysis. This is a statistical method used to reconstruct a reliable evolutionary tree. To say that a fossil species is an early hominin without performing this kind of analysis is like giving the result of an equation without actually doing the maths.</p>
<p><strong>What sort of further research and clarification is needed to confirm or debunk this theory of European origins?</strong></p>
<p>A <a href="http://www.sciencedirect.com/science/article/pii/S0047248416300100">phylogenetic analysis</a> is crucial. This is a way to reconstruct the evolutionary tree of species and to address the hypotheses of any relationship between them. </p>
<p>It will allow scientists to assess this fossil jaw’s real position in the evolutionary tree of Primates and to actually test if the similarities observed between <em>Graecopithecus</em> and hominins were acquired independently or were inherited from a real common ancestor.</p>
<p><strong>And if their claim turns out to be true, would that mean we need to totally rewrite history?</strong></p>
<p>The <a href="https://www.nature.com/nature/ancestor/pdf/115195.pdf">theory</a> that humankind originated in Europe is an old one. It was abandoned after 1924 when the first <em>Australopithecus</em> was discovered in South Africa. </p>
<p>Since then, thousands of fossils have been found around Africa that strongly support the “African origins” hypothesis. Even if this new fossil actually turns out to be a hominin, it would only be an outlier – like a drop in the ocean. It would change very few things, because much more and far better preserved material would be necessary to totally disprove the African origin of humankind.</p>
<p>It would open a brand new area of research, but would not change textbooks.</p><img src="https://counter.theconversation.com/content/78280/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Benoit receives funding from The Claude Leon Foundation; PAST and its Scatterlings projects; the National Research Foundation of South Africa; and the DST-NRF Centre of Excellence in Palaeosciences (CoE in Palaeosciences). </span></em></p>The theory that humankind originated in Europe is an old one. It was abandoned in 1924 when the first Australopithecus was discovered in South Africa.Julien Benoit, Postdoc in Vertebrate Palaeontology, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/773522017-05-09T09:21:02Z2017-05-09T09:21:02ZMore secrets of human ancestry emerge from South African caves<figure><img src="https://images.theconversation.com/files/168384/original/file-20170508-20740-sdijm5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">"Neo" skull of Homo naledi from the Lesedi Chamber.</span> <span class="attribution"><span class="source">John Hawks/Wits University</span></span></figcaption></figure><p><em>Africa’s richest fossil hominin site has revealed more of its treasure. It’s been a year and a half since scientists announced that a new hominin species, which they called Homo naledi, had been discovered in the Rising Star Cave outside Johannesburg.</em></p>
<p><em>Now they say they have <a href="https://elife.elifesciences.org/">established and published</a> the age of the original naledi fossils that garnered global headlines in 2015. Homo naledi lived sometime between 335 and 236 thousand years ago, making it relatively young.</em></p>
<p><em>They’ve also <a href="https://elife.elifesciences.org/">announced</a> the discovery of a second chamber in the Rising Star cave system, which contained additional Homo naledi specimens. These include a child and the partial skeleton of an adult male with a well-preserved skull. They have named the skeleton “Neo” – a Sesotho word meaning “a gift”.</em></p>
<p><em>The Conversation Africa’s Science Editor Natasha Joseph asked Professor John Hawks, a member of the team, to explain the story behind these finds.</em></p>
<p><strong>To an ordinary person, 236 000 years is a very long time ago. Why does the team suggest that in fact, <em>Homo naledi</em> is a “young” species?</strong></p>
<p>The course of <a href="http://humanorigins.si.edu/education/introduction-human-evolution">human evolution</a> has taken the last seven million years since our ancestors diverged from those of chimpanzees and bonobos. The first two-thirds of that long history, called <em><a href="http://humanorigins.si.edu/evidence/human-fossils/species/australopithecus-afarensis">australopiths</a></em>, were apelike creatures who developed the trick of walking upright on two legs. </p>
<p>Around two million years ago some varieties of hominins took the first real steps in a human direction. They’re the earliest clear members of our genus, <em>Homo</em>, and belong to species like <em>Homo habilis</em>, <em>Homo erectus</em> and <em>Homo rudolfensis.</em></p>
<p><em>Homo naledi</em> looks in many ways like these first members of <em>Homo</em>. It’s even more primitive than these species in many ways, and has a smaller brain than any of them. People outside our team who have studied the fossils mostly thought they should be around the same age. A few had the radical idea that <em>H. naledi</em> might have lived more recently, maybe around <a href="https://www.sciencenews.org/article/new-dating-suggests-younger-age-homo-naledi">900,000 years ago</a>. </p>
<p>Nobody thought that these fossils could actually have come from the same recent time interval when modern humans were evolving, a mere 236 to 335 thousand years ago. </p>
<p><strong>How do you figure out a fossil’s age?</strong></p>
<p>We applied six different methods. The most valuable of these were <a href="http://hyperphysics.phy-astr.gsu.edu/hbase/molecule/esr.html">electron spin resonance</a> (ESR) dating, and <a href="http://www.geo.arizona.edu/Antevs/ecol438/uthdating.html">uranium-thorium</a> (U-Th) dating. ESR relies on the fact that teeth contain tiny crystals, and the electron energy in these crystals is affected by natural radiation in the ground over long periods of time after fossils are buried. </p>
<p>U-Th relies on the fact that water drips into caves and forms layers of calcite, which contain traces of uranium. The radioactive fraction of uranium decays into thorium slowly over time. So the proportion of thorium compared to uranium gives an estimate of the time since the calcite layers formed. One of these calcite deposits, called a flowstone, formed above the <em>H. naledi</em> fossils in the Dinaledi Chamber. That flowstone helps to establish the minimum age: the fossils must be older than the flowstone above them. </p>
<p>For these two methods, our team engaged two separate labs and asked them to process and analyse samples without talking to each other. Their processes produced the same results. This gives us great confidence that the results are reliable. </p>
<p><strong>What does the discovery of <em>Homo naledi’s</em> age mean for our understanding of human history and evolution?</strong></p>
<p>For at least the past 100 years, anthropologists have assumed that most of the evolution of <em>Homo</em> was a story of progress: brains got bigger over time, technology became more sophisticated and teeth got smaller as people relied more upon cleverness to get better food and prepare it by cooking. </p>
<p>We thought that once culture really got started, our evolution was driven by a feedback loop – better food allowed bigger brains, more clever adaptations, more sophisticated communication. That enabled better technology, which yielded more food, and so on like a snowball rolling downhill.</p>
<p>No other hominin species could compete with this human juggernaut. You would never see more than one form of human in a single part of the world, because the competition would be too intense. Other forms, like Neanderthals, existed within regions of the world apart from the mainstream leading to modern humans in Africa. But even they were basically human with large brains. </p>
<p>That thinking was wrong. </p>
<p>Africa south of the equator is the core of human evolutionary history. That’s where today’s human populations were most genetically diverse, and that diversity is just a small part of what once existed there. Different lineages of archaic humans once lived in this region. Anthropologists have found a few fossil remnants of these archaic populations. They’ve tried to connect those remnants in a straight line. But the genetic evidence suggests that they were much more complex, with deep divisions that occasionally intertwined. </p>
<p><em>H. naledi</em> shows a lineage that existed for probably more than a million years, maybe two million years, from the time it branched from our family tree up to the last 300,000 years. During all this time, it lived in Africa with archaic lineages of humans, with the ancestors of modern humans, maybe with early modern humans themselves. It’s strikingly different from any of these other human forms, so primitive in many aspects. It represents a lost hominin community within which our species evolved. </p>
<p>I think we have to reexamine much of what we thought we knew about our shared evolutionary past in Africa. We know a lot of information from a few very tiny geographic areas. But the largest parts of the continent are unknown – they have no fossil record at all. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168540/original/file-20170509-10997-1xlntft.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">Explorers Mathabela Tsikoane, Maropeng Ramalepa, Dirk van Rooyen, Steven Tucker (seated), and Rick Hunter (seated) inside the Rising Star cave system.</span>
<span class="attribution"><span class="source">Wits University/Marina Elliott</span></span>
</figcaption>
</figure>
<p>We’re working to change that, and as our team and others make new discoveries, I’m pretty sure we are going to find more lineages that have been hidden to us. <em>H. naledi</em> will not be the last. </p>
<p><strong>The first <em>Homo naledi</em> discoveries were made in the Dinaledi Chamber. What led researchers to the second chamber? And what did you find there?</strong></p>
<p>The Dinaledi Chamber is one of the most significant fossil finds in history. After excavating only a very tiny part of this chamber, the sample of hominin specimens is already larger than any other single assemblage in Africa.</p>
<p>The explorers who first found these bones, Rick Hunter and Steven Tucker, saw what the team was doing when they were excavating in the chamber. The pair realised that they might have seen a similar occurrence in another part of the cave system. The Rising Star system has more than two kilometres of mapped passages underground. In another deep chamber, accessed again through very tight underground squeezes, there were hominin bones exposed on the surface. </p>
<p>Our team first began systematic survey of this chamber, which we named the Lesedi Chamber, in 2014. For two years Marina Elliott led excavations, joined at times by most of the team’s other experienced underground excavators. They were working in a situation where bones are jammed into a tight blind tunnel. Only one excavator can fit at a time, belly-down, feet sticking out. It is an incredibly challenging excavation circumstance. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168534/original/file-20170509-20725-1o5t500.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">Geologist Dr Hannah Hilbert-Wolf studying difficult to reach flowstones in a small side passage in the Dinaledi Chamber.</span>
<span class="attribution"><span class="source">Wits University</span></span>
</figcaption>
</figure>
<p>The most significant discovery is a partial skeleton of <em>H. naledi</em>, with parts of the arms, legs, a lot of the spine and many other pieces, as well as a beautifully complete skull and jaw. We named this skeleton “Neo”. We also recovered fragments of at least one other adult individual, and one child, although we suspect these bones may come from one or two more individuals. </p>
<p><strong>Is there a way for people to view these discoveries in person?</strong></p>
<p>On May 25 – <a href="http://www.sahistory.org.za/dated-event/organisation-african-unity-formed-and-africa-day-declared">Africa Day</a> – <a href="http://www.maropeng.co.za/">Maropeng</a> at the Cradle of Humankind World Heritage Site outside Johannesburg will open a new exhibit with the discoveries from the Lesedi Chamber and the Dinaledi Chamber together for the first time. </p>
<p>For people outside South Africa, the data from our three-dimensional scans of the new Lesedi fossils are available <a href="http://www.morphosource.org">online</a>.</p>
<p>Anyone can download the 3D models, and people with access to a 3D printer can print their own physical copies of the new fossils, as well as the fossils from the Dinaledi Chamber. It’s a great way for people to see the evidence for themselves.</p><img src="https://counter.theconversation.com/content/77352/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Hawks receives funding from National Geographic, the Fulbright Scholar Program and the National Research Foundation</span></em></p>Evidence of Homo naledi’s age suggests we need to rethink our understanding of human history and evolution.John Hawks, Paleoanthropologist, University of Wisconsin-MadisonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/713462017-01-18T15:01:37Z2017-01-18T15:01:37ZWhen it comes to big finds, scientists need more than just luck and chance<figure><img src="https://images.theconversation.com/files/152838/original/image-20170116-8769-cublv1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The author's backpack was hiding this almost complete therapsid fossil. Was finding it all down to luck?</span> <span class="attribution"><span class="source">Julien Benoit</span></span></figcaption></figure><p>The history of science abounds with stories about discoveries made by chance. One of the most famous cases, involves French physicist <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/becquerel-bio.html">Antoine Henri Becquerel</a>, who accidentally discovered radioactivity by leaving a piece of granite on photographic paper in a drawer of his desk. Another, is the story of Scottish biologist <a href="http://www.nobelprize.org/nobel_prizes/medicine/laureates/1945/fleming-bio.html">Alexander Fleming</a>, who forgot his bacterial cultures at home when he went on holiday. They rotted – and Fleming discovered penicillin.</p>
<p>These charming stories showcase science’s most human aspect: men and women who make lucky mistakes that can save lives or change the world. Even scientists are happy to believe these tales, though they don’t do much justice to our colleagues’ expertise. </p>
<p>But is this really the way science works? Can anybody, scientist or not, rely on luck to make important discoveries? My own “lucky strike” as a palaeontologist – finding a nearly complete fossil of a pre-mammalian ancestor – helped me to understand that good science isn’t rooted in chance. It’s based on people with expertise being in the right place at the right time, equipped with enough knowledge to know what they’re looking at. </p>
<h2>A fossil find</h2>
<p>My moment of “luck” occurred in South Africa’s Karoo in 2015. I’d been invited to join an international team of palaeontologists led by Professor Bruce Rubidge and Dr Michael Day from the University of the Witwatersrand in Johannesburg. We came from Europe, South America and Africa to look for the fossils of <a href="http://www.newworldencyclopedia.org/entry/Therapsid">pre-mammalian therapsids</a>, which date back around 260 million years.</p>
<p>The Karoo is a semi-arid desert mostly populated by sheep and thorny bushes that covers a huge swathe of South Africa between Johannesburg and Cape Town. Hundreds of millions of years ago it was covered with lakes, rivers, dense primeval vegetation. Large reptile-like beasts roamed this landscape.</p>
<p>On the day in question we were fossil hunting between the towns of Sutherland and Fraserburg. There were rich pickings: Bruce and Michael had identified an area filled with fossil remains. So, we were in the right place. And, crucially, my shoes were totally wrong for the Karoo. Between the thorns and the heat, the plastic of my shoes had melted and their toes had been ripped open by thorns.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/152839/original/image-20170116-8806-x8ur11.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">Alexander Fleming.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>So I sat down on an outcrop of sandstone that formed a natural bench, putting my backpack down next to me. A brief burst of rain brought a bunch of critters out from their hiding places to drink; an astonishing spectacle. When the sun returned, I felt ready to carry on. I picked up my backpack – and saw the beautiful, nearly complete fossilised therapsid skeleton it had been covering.</p>
<p>It was 30cm long and in great condition, and it has been right next to me, under my backpack all the time ! I couldn’t contain my enthusiasm, exclaiming, “How lucky am I?”. And that’s when I started thinking about “luck” in the context of scientific discovery. Was I that lucky after all?</p>
<h2>Serendipity and science</h2>
<p>Bruce and Michael, two experts in their field, had chosen our prospecting spot carefully based on what they knew. They had sent out a complete team of palaeontologists who knew what to look for. This doesn’t look like luck to me: it was probability in action. </p>
<p>This is the very essence of what we call serendipity: the art of creating the good intellectual, scientific and experimental context for a “fortuitous” discovery to happen. Fleming may well have discovered penicillin by chance, but the conditions were right because he had all the equipment and specimens he needed.</p>
<p>Becquerel would never have realised what he’d found if he hadn’t been carefully studying natural fluorescence. His existing knowledge allowed him to recognise a major discovery.</p>
<p>Maybe I discovered this skeleton by chance – or perhaps I found it because that was what we were looking for, in the right place and with the right people.</p>
<p>My humble fossil was certainly far from the level of Fleming and Becquerel’s discoveries. But it offered a valuable reminder that pure luck can’t account for scientific breakthroughs. Hours of work, and countless people and money are invested to create the right opportunity for discoveries to happen. Serendipity happens when scientists create their own luck.</p><img src="https://counter.theconversation.com/content/71346/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Benoit receives funding from PAST and its scatterlings projects; the NRF; and the DST-NRF Centre of Excellence in Palaeosciences (CoE in Palaeosciences).</span></em></p>Good science isn’t rooted in chance. It’s based on people with expertise being in the right place at the right time, equipped with enough knowledge to know what they’re looking at.Julien Benoit, Postdoc in Vertebrate Palaeontology, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/640592016-09-26T19:07:15Z2016-09-26T19:07:15Z3D technology brings a lost mammalian ancestor back to life<figure><img src="https://images.theconversation.com/files/134406/original/image-20160817-3592-11nn3qp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A 3D model of the long-lost Scalopocynodon gracilis skull.</span> <span class="attribution"><span class="source">Evolutionary Studies Unit, Wits University</span></span></figcaption></figure><p>At the very beginning of the 1960s, a South African palaeontologist embarked on a series of ambitious works. Dr A.S. Brink wanted to better understand the anatomy and evolution of humans’ pre-mammalian ancestors, the <a href="http://www.newworldencyclopedia.org/entry/Therapsid">therapsids</a>. </p>
<p>Brink worked with therapsid skulls found in South Africa’s Karoo region. He ground the skulls at thin and regular intervals to assess their internal cranial anatomy. The technique, known as serial grinding, was commonly used at the time. </p>
<p>As he neared the end of the process on one of the skulls Brink realised that he had uncovered a unique specimen. The skull represented a <a href="http://blog.everythingdinosaur.co.uk/blog/_archives/2011/09/23/4908360.html">holotype</a>, which is the single specimen used in the definition of any new species. But by then it was too late.</p>
<p>More than 50 years later, we were among a group of scientists who followed in Brink’s footsteps. Our task was <a href="http://palaeo-electronica.org/content/2016/1478-reconstructing-scalopocynodon">to recreate</a> this unique specimen. Technology has moved on enormously in the last half century, so we were able to use 3D renderings and 3D printing – and one of our mammalian ancestors was reborn.</p>
<h2>Historical techniques</h2>
<p>South Africa was a good place for Brink’s work. The country’s Karoo region is home to <a href="https://theconversation.com/how-looking-250-million-years-into-the-past-could-save-modern-species-60338">a wealth</a> of therapsid fossils, making it an important place to study the ancestry of mammals. </p>
<p>Brink was not the first palaeontologist to use serial grinding. The technique emerged at the beginning of the 20th century. Before then scholars had to wait for the discovery of naturally preserved casts of internal structures, like the mold of the “fossil brain” of the <a href="http://humanorigins.si.edu/evidence/human-fossils/fossils/taung-child">Taung Child</a>, <em>Australopithecus africanus</em>. Or they had to break fossils open.</p>
<p>With its introduction, serial grinding became the only fully controlled way to access the “interior” of fossils. Because of their abundance, South African therapsids were among the first fossils to be studied using this new, revolutionary approach. Sadly, their abundance turned out to be a curse.</p>
<h2>Accidental destruction</h2>
<p>In 1961, Dr Brink started the serial grinding study of a well preserved skull. At this stage, he thought the specimen belonged to a common form of therapsid. </p>
<p>But during the process, the sections revealed anatomical structures that suggested the specimen may actually represent a new species of fossil therapsid previously unknown to science. By then it was too late to save the fossil: it had already been mostly ground down. Brink tried to compensate by making a very thorough and accurate description and drawings of the specimen. He named it <a href="http://wiredspace.wits.ac.za/handle/10539/16091"><em>Scalopocynodon gracilis</em></a>.</p>
<p>As in zoology, the designation of type specimens is the most critical step when naming a new species in palaeontology. This type specimen, called a holotype, is meant to serve as an anatomical reference for future comparative works. A new species can’t be recorded without a holotype. So this ground specimen was particularly important: it constituted the holotype of <em>Scalopocynodon gracilis</em>. </p>
<p>Sadly this valuable and irreplaceable piece of South Africa’s heritage and evidence of the evolution of pre-mammalian therapsids was lost. The irony is that it was destroyed by the very author of the species.</p>
<p><em>Scalopocynodon</em> was considered dead and forgotten – until 2016.</p>
<h2>Recreating our ancestor in 3D</h2>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=587&fit=crop&dpr=1 600w, https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=587&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=587&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=738&fit=crop&dpr=1 754w, https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=738&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/134407/original/image-20160817-3608-1fzwxbo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=738&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="attribution"><span class="source">Evolutionary Studies Institute, Wits University</span></span>
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<p>It’s then that a team from the Evolutionary Studies Institute at Johannesburg’s University of the Witwatersrand retrieved some of Dr Brink’s drawings of the <em>Scalopocynodon gracilis</em> from 1961. These drawings represent each thin section ground by Brink. Their detail presented us with an unprecedented opportunity to virtually reconstruct the long lost specimen of <em>Scalopocynodon gracilis</em>.</p>
<p>The drawings were digitised. Then, using cutting edge software and innovative computer-based technology, every slice was digitally reassembled in a single stack. This allowed us to reconstruct a 3D model of the original skull. Afterwards a physical model of <em>Scalopocynodon</em> was printed in 3D so we could recreate a life-sized reconstruction of this specimen.</p>
<p>To our knowledge, this is the first time 3D technology has been used to recreate and print in 3D a serially ground fossil vertebrate (though it is quite often used in invertebrates palaeontology).</p>
<p>This is a great initiative for South African heritage conservation. These techniques can be used on other fossils lost through serial grinding. </p>
<h2>Breathing new life</h2>
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<figcaption><span class="caption">Recreating a fossil using 3D technology is painstaking work.</span></figcaption>
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<p>The 3D printed skull, serving as a holotype, could also help to breathe new life into this mysterious specimen. Taxonomists can now study it and one day might be able to say definitively that Brink was right: <em>Scalopocynodon gracilis</em> was indeed different from any other therapsid.</p><img src="https://counter.theconversation.com/content/64059/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Benoit receives funding from from PAST and its Scatterlings projects; the National Research Foundation of South Africa; and the DST-NRF Centre of Excellence in Palaeosciences (CoE in Palaeosciences). </span></em></p><p class="fine-print"><em><span>Sandra Jasinoski received postdoctoral funding from the DST-NRF Centre of Excellence in Palaeosciences. </span></em></p>An old technique to explore the inside of fossils unfortunately ended up destroying some unique specimens. New technology has been used to reconstruct one such fossil.Julien Benoit, Postdoc in Vertebrate Palaeontology, University of the WitwatersrandSandra Jasinoski, Postdoc in Palaeontology, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/470812015-09-07T04:07:27Z2015-09-07T04:07:27ZWhat the use of ochre tells us about the capabilities of our African ancestry<figure><img src="https://images.theconversation.com/files/93984/original/image-20150906-14625-19q8v1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ochre is still used throughout parts of Africa as a form of sunscreen. Its uses go back 285,000 years. </span> <span class="attribution"><span class="source">Supplied</span></span></figcaption></figure><p>The use of <a href="https://www.academia.edu/12090780/Ochre_use_at_Sibudu_Cave_and_its_link_to_complex_cognition_in_the_Middle_Stone_Age">ochre</a> dates to the <a href="http://humanorigins.si.edu/evidence/behavior/tools/middle-tools">Middle Stone Age</a> and <a href="http://archaeology.about.com/od/mterms/qt/middle_paleolit.htm">Middle Palaeolithic</a>. The earliest evidence of its use in Africa dates 285 000 years.</p>
<p>In Africa, ochre is used for protection from the sun and as a barrier from insects such as mosquitos. It has also been scientifically proven to inhibit the effects of UV radiation. There are many other uses. </p>
<p><a href="http://archaeology.about.com/od/oterms/qt/Ochre.htm">Ochre</a> is an umbrella term for a range of earthy, iron-rich rocks composed of iron oxides or oxyhydroxides, such as shales, sandstones, mudstones and specularite. </p>
<h2>Why the fuss</h2>
<p>Ochre appears in the archaeological record around the same time as anatomically modern humans. Its use became more frequent from about 100,000 years ago at many Middle Stone Age sites. </p>
<p>At the same time, we find other significant developments in the material culture, such as new tool technologies and the use of a wide range of raw materials. Consequently, ochre is often seen as an indicator of “modern human behaviour” and cognitive development through its use as an indicator of symbolic behaviour. </p>
<p>This is reinforced by the preferential use of bright red ochre and ochre powder, as well as the deliberate engraving of ochre. Therefore, archaeological studies of the use of ochre can give fresh insights into the cognitive development of our early ancestors.</p>
<h2>Past and present uses of ochre</h2>
<p>Current and ethnographic uses of ochre have influenced interpretations of how it was used in the Middle and Later Stone Age. This must be done with caution because ochre has many different uses and we cannot assume that it was used in the same way in the past as it is today. Nevertheless, a great deal is now known about the properties of ochre. Here are some of its confirmed uses:</p>
<ul>
<li><p>Ochre is used as an adhesive. Its powder is an effective aggregate in resin adhesives to mount tools onto handles or <a href="http://www.pnas.org/content/106/24/9590.full">shafts</a>. Evidence of it being used in this way is found in the <a href="http://www.sciencedirect.com/science/article/pii/S1040618212001140">Middle Stone Age</a>. </p></li>
<li><p>It was also used to tan hide. Ochre has anti-bacterial qualities which prevent the breakdown of collagen. This helps <a href="http://www.researchgate.net/profile/Riaan_Rifkin/publication/257944765_Assessing_the_efficacy_of_red_ochre_as_a_prehistoric_hide-tanning_ingredient/links/0deec5266bd1158551000000.pdf">preserve hides</a>. There is no direct evidence of its use as a hide tanning substance in the Middle Stone Age as no hides are preserved. But <a href="http://www.sciencedirect.com/science/article/pii/S0305440310002761">traces</a> on the ochre pieces indicate that some pieces were rubbed on <a href="http://www.eva.mpg.de/evolution/pdf/Soressi%20et%20D'errico%202007%20in%20Vandermeersch%20et%20Maureille.pdf">soft materials</a>. </p></li>
<li><p>It is more commonly known for protection from the sun protection. Ochre-based pastes has been used as protection from the sun as well as a barrier from insects like <a href="http://www.researchgate.net/profile/Riaan_Rifkin/publication/264623585_Ethnographic_and_experimental_perspectives_on_the_efficacy_of_red_ochre_as_a_mosquito_repellent/links/559d2dd208ae76bed0bad645.pdf">mosquitos</a>. It has been scientifically proven to inhibit the effects of <a href="http://www.sajs.co.za/sites/default/files/publications/pdf/Rifkin_Research%20Article_0.pdf">ultra-violet radiation</a>. It is still used as a sunscreen today, for example, by the Ovahimba in Namibia. </p></li>
<li><p>Ochre pigments were, and still are, widely used in paint and artwork. Many of the red and yellow pigments in rock art panels around the world are made with ochre-based paints. There is limited evidence for the creation of ochre paint in the Middle Stone Age, but 30,000 years ago its use as a <a href="http://www.sciencemag.org/content/334/6053/219.full">paint</a> was established.</p></li>
</ul>
<h2>Connecting the dots</h2>
<p>Links between the visible uses of ochre and cognition have not been clearly defined. To reconstruct the technology and processes involved in using ochre, it is important to understand the physical and chemical qualities of this material, whether as pieces or in powdered form. It is then possible to conclude whether ochre was used in the same way in the ancient past as it was in the recent past.</p>
<p>The main ways that ochre was used in the Middle Stone Age was by grinding pieces on coarse sandstone slab to create powder, scoring (or engraving) pieces with sharp tools, or rubbing ochre on soft surfaces, such as animal hide or human skin. </p>
<p>Grinding, to create a powder, is the most common use trace on Middle Stone Age ochre pieces. Red ochre appears to be preferentially ground at many Middle Stone Age sites implying that bright red powder was desired. Additionally, ochre powder has been found on various archaeological artefacts in this period such as stone tools, grindstones, perforated shell beads and bone tools. </p>
<p>The construction of thought-and-action cognitive sequences for activities involving the use of ochre has helped to reconstruct which actions require enhanced cognitive functions.</p>
<p>To model these sequences, each activity performed with ochre <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9398689&fileId=S0959774314000663">must be considered</a> – from collection, to possible modification by heat, to use with other tools, to discard.</p>
<p>By reconstructing the series of actions we can look at the <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8589664&fileId=S095977431200025X">cognitive requirements</a> needed to perform them, such as problem solving abilities, the need to switch attention between two concurrent activities, long range planning and response inhibition.</p>
<p>The requirement for cognitively complex abilities in some of the ochre-related activities in the Middle Stone Age suggests that the people living then had the advanced mental capabilities of people today. Ochre use could be a proxy for cognitive capabilities, and can therefore shed light on the evolution of the modern mind.</p>
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<p><em>This article is based on a submission by the author to the <a href="http://journals.cambridge.org/abstract_S0959774314000663">Cambridge Archaeological Journal</a>.</em></p><img src="https://counter.theconversation.com/content/47081/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tammy Reynard receives funding from The Centre of Excellence in Palaeosciences (CoE_PAL), The National Research Foundation (NRF), The Palaeontological Scientific Trust (PAST) and The Mellon Fondation.</span></em></p>Ochre has many uses. It can be used to shed information on the evolution of the modern mind.Tammy Hodgskiss, Postdoctoral Fellow, Evolutionary Studies Institute, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.