tag:theconversation.com,2011:/us/topics/later-stone-age-20089/articlesLater Stone Age – The Conversation2022-02-23T16:03:13Ztag:theconversation.com,2011:article/1754362022-02-23T16:03:13Z2022-02-23T16:03:13ZAncient DNA helps reveal social changes in Africa 50,000 years ago that shaped the human story<figure><img src="https://images.theconversation.com/files/446822/original/file-20220216-3870-1o2qb6l.jpg?ixlib=rb-1.1.0&rect=186%2C0%2C3661%2C2475&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Together with artifacts from the past, ancient DNA can fill in details about our ancient ancestors.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Kondoa_Irangi_Rock_Paintings_(51507918388).jpg">Nina R/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Every person alive on the planet today is descended from people who lived as hunter-gatherers in Africa. </p>
<p>The continent is the cradle of <a href="https://theconversation.com/how-a-handful-of-prehistoric-geniuses-launched-humanitys-technological-revolution-171511">human origins and ingenuity</a>, and <a href="https://theconversation.com/archaeological-discoveries-are-happening-faster-than-ever-before-helping-refine-the-human-story-128743">with each new fossil and archaeological discovery</a>, we learn more about our shared African past. Such research tends to focus on when our species, <em>Homo sapiens</em>, <a href="https://www.scientificamerican.com/article/how-homo-sapiens-became-the-ultimate-invasive-species/">spread out to other landmasses 80,000-60,000 years ago</a>. But what happened in Africa after that, and why don’t we know more about the people who remained?</p>
<p>Our 2022 study, conducted by an interdisciplinary team of 44 researchers based in 12 countries, <a href="https://www.nature.com/articles/s41586-022-04430-9">helps answer these questions</a>. By sequencing and analyzing ancient DNA (aDNA) from people who lived as long ago as 18,000 years, we roughly doubled the age of sequenced aDNA from sub-Saharan Africa. And this genetic information helps <a href="https://scholar.google.com/citations?user=GlrnQDgAAAAJ&hl=en&oi=ao">anthropologists</a> <a href="https://scholar.google.com/citations?user=MQkcYDYAAAAJ&hl=en&oi=ao">like</a> <a href="https://scholar.google.com/citations?user=3QKcZMoAAAAJ&hl=en&oi=ao">us</a> understand more about how modern humans were moving and mingling in Africa long ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="View from above of archaeological excavation" src="https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441914/original/file-20220121-8326-sxvlib.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">People took shelter in natural rock overhangs, leaving behind an archaeological record of their daily activities – and sometimes their graves. By digging carefully, archaeologists can connect information from aDNA to information about the social lives of these people.</span>
<span class="attribution"><span class="source">Jacob Davis</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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</figure>
<h2>Tracing our human past in Africa</h2>
<p><a href="https://theconversation.com/new-moroccan-fossils-suggest-humans-lived-and-evolved-across-africa-100-000-years-earlier-than-we-thought-78826">Beginning about 300,000 years ago</a>, people in Africa who looked like us – the earliest anatomically modern humans – also started behaving in ways that seem very human. They made <a href="https://www.smithsonianmag.com/science-nature/how-drastic-ecological-change-led-leap-forward-behavior-weapons-and-tools-180976101/">new kinds of stone tools and began transporting raw materials</a> up to 250 miles (400 kilometers), likely through trade networks. By 140,000-120,000 years ago, people made <a href="https://scitechdaily.com/early-humans-used-bone-tools-to-produce-clothing-in-morocco-120000-years-ago/">clothing from animal skins</a> and began to <a href="https://www.smithsonianmag.com/smart-news/worlds-oldest-jewelry-discovered-in-moroccan-cave-180978766/">decorate themselves with pierced marine shell beads</a>. </p>
<p>While early innovations appeared in a patchwork fashion, a more widespread shift happened around 50,000 years ago – around the same time that people started <a href="https://www.nationalgeographic.com/history/article/australia-aboriginal-early-human-evolution-spd">moving into places as distant as Australia</a>. New types of stone and bone tools became common, and people began <a href="https://theconversation.com/the-tiny-ostrich-eggshell-beads-that-tell-the-story-of-africas-past-128577">fashioning and exchanging ostrich eggshell beads</a>. And while most <a href="https://theconversation.com/an-ancient-san-rock-art-mural-in-south-africa-reveals-new-meaning-157177">rock art in Africa</a> is undated and badly weathered, an increase in <a href="https://theconversation.com/what-the-use-of-ochre-tells-us-about-the-capabilities-of-our-african-ancestry-47081">ochre pigment at archaeological sites</a> hints at an explosion of art. </p>
<p>What caused this shift, known as the <a href="https://en.wikipedia.org/wiki/Late_Stone_Age">Later Stone Age</a> transition, has been a longstanding archaeological mystery. Why would certain tools and behaviors, which up until that point had appeared in a piecemeal way across Africa, suddenly become widespread? Did it have something to do with changes in the number of people, or how they interacted? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Nine disc-shaped beads" src="https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=474&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=474&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=474&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=596&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=596&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441913/original/file-20220121-9541-bx79fs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=596&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Beads made from ostrich eggshell were hot trade items and can show the extent of ancient social networks.</span>
<span class="attribution"><span class="source">Jennifer Miller</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>The challenge of accessing the deep past</h2>
<p>Archaeologists reconstruct human behavior in the past mainly through things people left behind – remains of their meals, tools, ornaments and <a href="https://theconversation.com/how-we-discovered-the-oldest-human-burial-in-africa-and-what-it-tells-us-about-our-ancestors-160122">sometimes even their bodies</a>. These records may accumulate over thousands of years, creating views of daily livelihoods that are really averages over long periods of time. However, it’s hard to study ancient demography, or how populations changed, from the archaeological record alone. </p>
<p>This is where DNA can help. When combined with evidence from archaeology, linguistics and oral and written history, scientists can piece together how people moved and interacted based on which groups share genetic similarities.</p>
<p>But DNA from living people can’t tell the whole story. African populations have been transformed over the past 5,000 years by the <a href="https://theconversation.com/ancient-dna-is-revealing-the-origins-of-livestock-herding-in-africa-114387">spread of herding and farming</a>, the <a href="https://theconversation.com/how-we-recreated-a-lost-african-city-with-laser-technology-92852">development of cities</a>, <a href="https://theconversation.com/archaeology-shows-how-ancient-african-societies-managed-pandemics-138217">ancient pandemics</a> and the ravages of <a href="https://theconversation.com/a-digital-archive-of-slave-voyages-details-the-largest-forced-migration-in-history-74902">colonialism and slavery</a>. These processes caused <a href="https://www.nytimes.com/2020/02/12/science/west-africa-ancient-humans.html">some lineages to vanish</a> and <a href="https://theconversation.com/mitochondrial-dna-reveals-unexpected-ancestral-connections-122053">brought others together</a>, forming new populations. </p>
<p>Using present-day DNA to reconstruct ancient genetic landscapes is like reading a letter that was left out in the rain: some words are there but blurred, and some are gone completely. Researchers need ancient DNA from archaeological human remains to explore human diversity in different places and times and to understand what factors shaped it.</p>
<p>Unfortunately, aDNA from Africa is particularly hard to recover because the continent straddles the equator and heat and humidity degrade DNA. While the <a href="https://www.scientificamerican.com/article/oldest-ancient-human-dna-details-dawn-of-neandertals/">oldest aDNA from Eurasia is roughly 400,000 years old</a>, all sequences from sub-Saharan Africa to date have been younger than around 9,000 years. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map with markers showing distribution of ancient DNA data in Africa, and the world." src="https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=625&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=625&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=625&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=785&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=785&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444879/original/file-20220207-47158-11n9ym1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=785&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map of all published ancient genomes, with black dots scaled to the number of individuals’ genomes. Blue dots indicate Later Stone Age foragers comparable to those in our study. Red stars indicate individuals reported for the first time in our study. Inset map underscores the gap between Africa and other parts of the world in terms of published ancient genomes. Ancient DNA preserved between the Tropics of Cancer and Capricorn is rare.</span>
<span class="attribution"><span class="source">Mary Prendergast; basemaps by Natural Earth</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Breaking the ‘tropical ceiling’</h2>
<p>Because each person carries genetic legacies inherited from generations of their ancestors, our team was able to use DNA from individuals who lived between 18,000-400 years ago to explore how people interacted as far back as the last 80,000-50,000 years. This allowed us, for the first time, to test whether demographic change played a role in the Later Stone Age transition. </p>
<p><a href="https://www.nature.com/articles/s41586-022-04430-9">Our team sequenced aDNA</a> from six individuals buried in what are now Tanzania, Malawi and Zambia. We compared these sequences to previously studied aDNA from 28 individuals buried at sites stretching from Cameroon to Ethiopia and down to South Africa. We also generated new and improved DNA data for 15 of these people, trying to extract as much information as possible from the small handful of ancient African individuals whose DNA is preserved well enough to study.</p>
<p>This created the largest genetic dataset so far for studying the population history of ancient African foragers – people who hunted, gathered or fished. We used it to explore population structures that existed prior to the sweeping changes of the past few thousand years.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Museum building, palm trees" src="https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444614/original/file-20220205-23-d1055k.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">National Museum of Tanzania in Dar es Salaam. Ancient DNA studies in Africa are made possible by the efforts of curators to protect and preserve remains in tropical conditions.</span>
<span class="attribution"><span class="source">Mary Prendergast</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>DNA weighs in on a longstanding debate</h2>
<p>We found that people did in fact change how they moved and interacted around the Later Stone Age transition.</p>
<p>Despite being separated by thousands of miles and years, all the ancient individuals in this study were descended from the same three populations related to ancient and present-day eastern, southern and central Africans. The presence of eastern African ancestry as far south as Zambia, and southern African ancestry as far north as Kenya, indicates that people were moving long distances and having children with people located far away from where they were born. The only way this population structure could have emerged is if people were moving long distances over many millennia. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Lush African landscape" src="https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446008/original/file-20220211-21-gafkub.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">Genetic data now suggests that people moved and mingled across the eastern African Rift Valley during the Ice Ages.</span>
<span class="attribution"><span class="source">Elizabeth Sawchuk</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Additionally, our research showed that almost all ancient eastern Africans shared an unexpectedly high number of genetic variations with hunter-gatherers who today live in central African rainforests, making ancient eastern Africa truly a genetic melting pot. We could tell that this mixing and moving happened after about 50,000 years ago, when there was a major split in central African forager populations.</p>
<p>We also noted that the individuals in our study were genetically most like only their closest geographic neighbors. This tells us that after around 20,000 years ago, the foragers in some African regions were almost exclusively finding their partners locally. This practice must have been extremely strong and persisted for a very long time, as our results show that some groups remained genetically independent of their neighbors over several thousand years. It was especially clear in Malawi and Zambia, where the only close relationships we detected were between people buried around the same time at the same sites. </p>
<p>We don’t know why people began “living locally” again. Changing environments as the last Ice Age peaked and waned between about 26,000-11,500 years ago may have made it more economical to forage closer to home, or perhaps elaborate exchange networks reduced the need for people to travel with objects.</p>
<p>Alternatively, new group identities may have emerged, restructuring marriage rules. If so, we would expect to see artifacts and other traditions like rock art diversify, with specific types clumped into different regions. Indeed, <a href="https://www.theguardian.com/science/2022/jan/16/trail-of-african-bling-reveals-50000-year-old-social-network">this is exactly what archaeologists find</a> – a trend known as regionalization. Now we know that this phenomenon not only affected cultural traditions, but also the flow of genes. </p>
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<a href="https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="workers at a table sort tiny items by hand" src="https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446872/original/file-20220216-20-cuzc12.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">Recovering and sorting archaeological remains is a slow and laborious process, where even small fragments can tell big stories.</span>
<span class="attribution"><span class="source">Chelsea Smith</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>New data, new questions</h2>
<p>As always, <a href="https://theconversation.com/ancient-dna-is-a-powerful-tool-for-studying-the-past-when-archaeologists-and-geneticists-work-together-111127">aDNA research raises as many questions as answers</a>. Finding central African ancestry throughout eastern and southern Africa prompts anthropologists to reconsider how interconnected these regions were in the distant past. This is important because central Africa has remained archaeologically understudied, in part because of political, economic and logistical challenges that make research there difficult. </p>
<p>Additionally, while genetic evidence supports a major demographic transition in Africa after 50,000 years ago, we still don’t know the key drivers. Determining what triggered the Later Stone Age transition will require closer examination of regional environmental, archaeological and genetic records to understand how this process unfolded across sub-Saharan Africa.</p>
<p>Finally, this study is a stark reminder that researchers still have <a href="https://theconversation.com/lesson-from-brazil-museums-are-not-forever-102692">much to learn from ancient individuals and artifacts</a> held in African museums, and highlights the <a href="https://theconversation.com/what-its-like-curating-ancient-fossils-a-palaeontologist-shares-her-story-96555">critical role of the curators</a> who steward these collections. While some human remains in this study were recovered within the past decade, others have been in museums for a half-century.</p>
<p>Even though technological advances are pushing back the time limits for aDNA, it is important to remember that scientists have only just begun to understand human diversity in Africa, past and present.</p>
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<p class="fine-print"><em><span>Elizabeth Sawchuk receives funding from the Social Sciences and Humanities Research Council of Canada. </span></em></p><p class="fine-print"><em><span>Jessica Thompson has received funding from the Leakey Foundation, National Geographic Society, Wenner-Gren Foundation, Australian Research Council, National Science Foundation, and Hyde Family Foundation. </span></em></p><p class="fine-print"><em><span>Mary Prendergast does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A new study doubles the age of ancient DNA in sub-Saharan Africa, revealing how people moved, mingled and had children together over the last 50,000 years.Elizabeth Sawchuk, Banting Postdoctoral Fellow and Adjunct Professor of Anthropology, University of AlbertaJessica Thompson, Assistant Professor of Anthropology, Yale UniversityMary Prendergast, Associate Professor of Anthropology, Rice UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1237822019-09-18T13:12:47Z2019-09-18T13:12:47ZPasha 36: The sounds of our ancestors<figure><img src="https://images.theconversation.com/files/292948/original/file-20190918-187967-1rev7zy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pendants</span> </figcaption></figure><p>Studying the Middle and Later Stone Age, which was about 300 000 to 300 years ago in South Africa, is a vital way to learn about an important period for our ancestors. </p>
<p>We know a fair amount about the tools and the paintings made by people of that time. But very little is known about the sounds that people made and listened to. This lack of knowledge made a group of South African researchers curious about these sounds – and so they set out to learn more. Some of their findings suggest that an instrument known as a woer woer, akin to a bullroarer, was among the key sounds of the time.</p>
<p>In today’s episode of Pasha Sarah Wurz, a professor at the University of the Witwatersrand, and Joshua Kumbani, a PhD student at the same university, discuss these ancient sounds and their purposes.</p>
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Read more:
<a href="https://theconversation.com/how-our-african-ancestors-made-sound-in-the-stone-age-121142">How our African ancestors made sound in the Stone Age</a>
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<p><strong>Photo:</strong>
Photo taken of the pendants used in the research. <a href="https://www.researchgate.net/publication/331558496_A_functional_investigation_of_southern_Cape_Later_Stone_Age_artefacts_resembling_aerophones">Academic paper</a></p>
<p><strong>Music</strong>
“Happy African Village” by John Bartmann found on <a href="http://freemusicarchive.org/music/John_Bartmann/Public_Domain_Soundtrack_Music_Album_One/happy-african-village">FreeMusicArchive.org</a> licensed under <a href="https://creativecommons.org/publicdomain/zero/1.0/">CC0 1</a>.</p>
<p><strong>Sounds</strong>
The sounds of the replica bullroarer & the woer woer in action.
Source: Neil Rusch, personal archive.</p><img src="https://counter.theconversation.com/content/123782/count.gif" alt="The Conversation" width="1" height="1" />
The sounds our ancestors made are important because they teach us about spaces and behaviour and rituals of the time.Ozayr Patel, Digital EditorLicensed 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>
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<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>
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<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.