tag:theconversation.com,2011:/fr/topics/human-migration-1981/articles
Human migration – The Conversation
2023-08-17T19:42:11Z
tag:theconversation.com,2011:article/211712
2023-08-17T19:42:11Z
2023-08-17T19:42:11Z
A changing climate, growing human populations and widespread fires contributed to the last major extinction event − can we prevent another?
<p>Over the past decade, deadly wildfires have become increasingly common because of both <a href="https://www.scientificamerican.com/article/climate-change-is-escalating-californias-wildfires/">human-caused climate change</a> and <a href="https://www.nytimes.com/2023/08/13/us/hawaii-wildfire-factors.html">disruptive land management practices</a>. Southern California, where the three of us live and work, has been <a href="https://ktla.com/news/the-cities-where-wildfires-threaten-the-most-homes-in-california/">hit especially hard</a>.</p>
<p>Southern California also experienced a wave of wildfires 13,000 years ago. These fires permanently transformed the region’s vegetation and <a href="https://www.science.org/doi/10.1126/science.abo3594">contributed to Earth’s largest extinction</a> in more than 60 million years.</p>
<p>As <a href="https://www.ioes.ucla.edu/person/emily-lindsey/">paleontologists</a>, <a href="https://nhm.org/person/dunn-regan">we have</a> a <a href="https://scholar.google.com/citations?user=_FveDz4AAAAJ&hl=en">unique perspective</a> on the long-term causes and consequences of environmental changes, both those linked to natural climate fluctuations and those wrought by humans. </p>
<p><a href="https://www.science.org/doi/10.1126/science.abo3594">In a new study</a>, published in August 2023, we sought to understand changes that were happening in California during the last major extinction event at the <a href="https://www.britannica.com/science/Pleistocene-Epoch">end of the Pleistocene</a>, a time period known as the Ice Age. This event wiped out <a href="https://www.smithsonianmag.com/science-nature/what-happened-worlds-most-enormous-animals-180964255/">most of Earth’s large mammals</a> between about 10,000 and 50,000 years ago. This was a time marked by dramatic climate upheavals and rapidly spreading human populations. </p>
<h2>The last major extinction</h2>
<p>Scientists often call the past 66 million years of Earth’s history the Age of Mammals. During this time, our furry relatives took advantage of the <a href="https://www.nhm.ac.uk/discover/how-an-asteroid-caused-extinction-of-dinosaurs.html">extinction of the dinosaurs</a> to become the dominant animals on the planet. </p>
<p>During the Pleistocene, Eurasia and the Americas teemed with enormous beasts like woolly mammoths, giant bears and dire wolves. Two species of camels, three species of ground sloths and five species of large cats <a href="https://tarpits.org/research-collections/tar-pits-collections/mammal-collections">roamed what is now Los Angeles</a>.</p>
<p>Then, abruptly, they were gone. All over the world, the large mammals that had characterized global ecosystems for tens of millions of years disappeared. North America <a href="https://www.doi.org/10.1146/annurev.ecolsys.34.011802.132415">lost more than 70%</a> of mammals weighing more than 97 pounds (44 kilograms). South America lost more than 80%, Australia nearly 90%. Only Africa, Antarctica and a few remote islands retain what could be considered “natural” animal communities today.</p>
<p>The reason for these extinctions remains obscure. For decades, paleontologists and archaeologists have debated potential causes. What has befuddled scientists is not that there are no obvious culprits but that there are too many. </p>
<p>As the last ice age ended, a warming climate led to altered weather patterns and the reorganization of <a href="https://doi.org/10.1016/j.quascirev.2015.08.029">plant communities</a>. At the same time, human populations were rapidly increasing and <a href="https://www.worldhistory.org/article/1070/early-human-migration/">spreading around the globe</a>. </p>
<p>Either or both of these processes could be implicated in the extinction event. But the fossil record of any region is usually too sparse to know exactly when large mammal species disappeared from different regions. This makes it difficult to determine whether habitat loss, resource scarcity, natural disasters, human hunting or some combination of these factors is to blame.</p>
<h2>A deadly combination</h2>
<p>Some records offer clues. <a href="https://tarpits.org/">La Brea Tar Pits</a> in Los Angeles, the world’s richest ice age fossil site, preserves the bones of thousands of large mammals that were trapped in viscous asphalt seeps <a href="https://resolver.caltech.edu/CaltechAUTHORS:20191203-160736818">over the past 60,000 years</a>. Proteins in these bones can be precisely dated <a href="https://doi.org/10.1016/j.quageo.2014.03.002">using radioactive carbon</a>, giving scientists unprecedented insight into an ancient ecosystem and an opportunity to illuminate the timing – and causes – of its collapse. </p>
<p>Our recent study from La Brea Tar Pits and <a href="https://en.wikipedia.org/wiki/Lake_Elsinore">nearby Lake Elsinore</a> has unearthed evidence of a dramatic event 13,000 years ago that permanently transformed Southern California’s vegetation and <a href="https://www.science.org/doi/10.1126/science.abo3594">caused the disappearance</a> of La Brea’s iconic mega-mammals. </p>
<p>Sediment archives from the lake’s bottom and archaeological records provide evidence of a deadly combination – a warming climate <a href="https://doi.org/10.1002/jqs.3018">punctuated by decadeslong droughts</a> and rapidly rising human populations. These factors pushed the Southern California ecosystem to a tipping point. </p>
<p><a href="https://www.doi.org/10.1126/sciadv.1501682">Similar combinations</a> of climate warming and human impacts have been blamed for ice age extinctions elsewhere, but our study found something new. The catalyst for this dramatic transformation seems to have been an unprecedented increase in wildfires, which were probably set by humans. </p>
<p>The processes that led to this collapse are familiar today. As California warmed coming out of the last ice age, the landscape became drier and forests receded. At La Brea, herbivore populations declined, probably from a combination of human hunting and habitat loss. Species associated with trees, like camels, disappeared entirely. </p>
<p>In the millennium leading up to the extinction, mean annual temperatures in the region <a href="https://doi.org/10.1016/j.epsl.2019.03.024">rose 10 degrees Farenheit</a> (5.5 degrees Celsius), and the lake began evaporating. Then, 13,200 years ago, the ecosystem entered a 200-year-long drought. Half of the remaining trees died. With fewer large herbivores to eat it, dead vegetation built up on the landscape. </p>
<p>At the same time, human populations began expanding across North America. And as they spread, people brought with them a powerful new tool – fire. </p>
<p>Humans and our ancestors have used fire for <a href="https://www.science.org/content/article/artificial-intelligence-may-have-unearthed-one-world-s-oldest-campfires">hundreds of thousands of years</a>, but fire has <a href="https://www.firescience.gov/projects/09-2-01-9/supdocs/09-2-01-9_Chapter_3_Fire_Regimes.pdf">different impacts in different ecosystems</a>. Charcoal records from Lake Elsinore reveal that before humans, fire activity was low in coastal Southern California. But 13,200 to 13,000 years ago, as human populations grew, fire in the region increased by an order of magnitude. </p>
<p>Our research suggests that the combination of heat, drought, herbivore loss and human-set fires had pushed this system to a <a href="https://www.nature.com/articles/nature11018">tipping point</a>. At the end of this period, Southern California was covered in chaparral plants, which thrive after fires. A new fire regime had become established, and the iconic La Brea megafauna had disappeared.</p>
<h2>Lessons for the future</h2>
<p>Studying the causes and consequences of the Pleistocene extinctions in California can provide valuable context for understanding today’s climate and biodiversity crises. A similar combination of climate warming, expanding human populations, biodiversity loss and human-ignited fires that characterized the ice age extinction interval in Southern California are <a href="https://www.doi.org/10.1126/science.abb0355">playing out again today</a>.</p>
<p>The alarming difference is that temperatures today are rising <a href="https://www.scientificamerican.com/article/todays-climate-change-proves-much-faster-than-changes-in-past-65-million-years/">10 times faster</a> than they did at the end of the ice age, primarily because of the burning of fossil fuels. This human-caused climate change has contributed to a fivefold increase in fire frequency and intensity and the amount of area burned in the state of California in the <a href="https://doi.org/10.1029/2019EF001210">past 45 years</a>. </p>
<p>While California is now <a href="https://earthobservatory.nasa.gov/images/148908/whats-behind-californias-surge-of-large-fires">famous for extreme fires</a>, our study reveals that fire is a relatively new phenomenon in this region. In the 20,000 years leading up to the extinction, the Lake Elsinore record shows very low incidence of any fire even during comparable periods of drought. Only after human arrival does fire become a regular part of the ecosystem. </p>
<p>Even today, <a href="https://www.businessinsider.com/pge-caused-california-wildfires-safety-measures-2019-10">downed power lines</a>, campfires and <a href="https://www.nytimes.com/2020/09/07/us/gender-reveal-party-wildfire.html">other human activities</a> start <a href="https://doi.org/10.1071/WF18026">over 90%</a> of wildfires in coastal California. </p>
<p>The parallels between the late Pleistocene megafaunal extinctions and today’s environmental crises are striking. The past teaches us that the ecosystems we depend upon are vulnerable to collapse when stressed by multiple intersecting pressures. Redoubling efforts to eliminate greenhouse gas emissions, prevent reckless fire ignitions and preserve Earth’s remaining megafauna can help avert another, even more catastrophic transformation.</p><img src="https://counter.theconversation.com/content/211712/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily Lindsey receives funding from the National Science Foundation, which funded some of the research reported in this article. </span></em></p><p class="fine-print"><em><span>Lisa N. Martinez receives funding from the National Science Foundation and the UCLA Endowed Chair in Geography of California and the American West. </span></em></p><p class="fine-print"><em><span>Regan E. Dunn receives funding from National Science Foundation and NASA. </span></em></p>
New findings from the La Brea Tar Pits in southern California suggest human-caused wildfires in the region, along with a warming climate, led to the loss of most of the area’s large mammals.
Emily Lindsey, Associate Curator, La Brea Tar Pits; Adjunct Faculty, Institute of the Environment and Sustainability, UCLA, University of California, Los Angeles
Lisa N. Martinez, Ph.D. Candidate in Geography, University of California, Los Angeles
Regan E. Dunn, Adjunct Professor of Earth Sciences, USC Dornsife College of Letters, Arts and Sciences
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/210056
2023-07-19T20:00:03Z
2023-07-19T20:00:03Z
Ancient DNA reveals the earliest evidence of the last massive human migration to Western Europe
<p>Nomadic animal-herders from the Eurasian steppe mingled with Copper Age farmers in southeastern Europe centuries earlier than previously thought. </p>
<p>In a new study <a href="https://www.nature.com/articles/s41586-023-06334-8">published in Nature</a>, we used ancient DNA to gain new insights into the spread of culture, technologies and ancestry at a crucial juncture in European history.</p>
<h2>How ancient DNA can help us understand change</h2>
<p>Humanity’s archaeological record reveals massive changes in cultural practices and <a href="https://theconversation.com/how-a-handful-of-prehistoric-geniuses-launched-humanitys-technological-revolution-171511">technologies</a>. </p>
<p>However, it is not always clear how these changes moved between different groups of people. It can happen either by a spread of ideas (such as through trade), or through the migration of people.</p>
<p>In Europe, there have been <a href="https://theconversation.com/european-invasion-dna-reveals-the-origins-of-modern-europeans-38096">two major migrations</a> in the past 10,000 years. </p>
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Read more:
<a href="https://theconversation.com/european-invasion-dna-reveals-the-origins-of-modern-europeans-38096">European invasion: DNA reveals the origins of modern Europeans</a>
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<p>First, there was an expansion of early farming groups from Anatolia around 9,000 years ago. This was associated with the introduction of farming practices and animal husbandry, a more sedentary lifestyle (permanent housing) and the wide use of pottery and new types of polished stone tools.</p>
<p>Second was the expansion of steppe herders from the <a href="https://www.oneearth.org/ecoregions/pontic-steppe/">Eurasian Pontic Steppes</a> around 5,000 years ago. This is associated with the spread of pastoralism and dairying technologies, a different type of ancestry and possibly some of the Indo-European languages.</p>
<p>In our <a href="https://www.nature.com/articles/s41586-023-06334-8">new research</a>, we studied the interaction between farming and pastoralist groups from the steppe from a new angle by analysing the genomes of 135 individuals from southeastern Europe and the northwestern Black Sea region, who lived between 4,000 and 7,000 years ago. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map showing the Black Sea and surrounding areas." src="https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=380&fit=crop&dpr=1 600w, https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=380&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=380&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=477&fit=crop&dpr=1 754w, https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=477&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/538000/original/file-20230718-21-739xyt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=477&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The area around Odesa was a ‘melting pot’ of cultures and ancestries.</span>
<span class="attribution"><span class="source">Modified from Penske et al. (2023)</span>, <span class="license">Author provided</span></span>
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<p>We uncovered previously unknown and significant genetic changes in the people living in these regions. We also found the presence of steppe ancestry in the contact zone in the northwestern Black Sea region around 5,500 years ago, some 500 years earlier than previously assumed. </p>
<h2>The Copper Age in southeastern Europe</h2>
<p>Southeastern Europe played an important role in the spread of farming across Europe after early farmers from Anatolia arrived around 9,000-8,000 years ago. Approximately 1,000 years later, easy access to copper, gold and salt led to the development of <a href="https://doi.org/10.1177/1461957107086121">many flourishing settlements</a> in parts of today’s Bulgaria and Romania. </p>
<p>Settlements on the Black Sea and major rivers such as the Danube thrived through contact and trade with surrounding areas. Similarity in material culture visible in the archaeological record across a wider region indicates a period of social and political stability of approximately 500 years, between around 6,200 and 6,700 years ago.</p>
<p>Ninety-five of the ancient genomes we analysed were from this period and region, and this cultural similarity and stability is reflected in the absence of major genetic differences. </p>
<h2>A new era and a melting pot of human interaction</h2>
<p>Following this period of stability, many Copper Age settlements were abruptly abandoned around 6,000 years ago. For almost the next 1,000 years so few people lived in southeastern Europe that the period is often referred to as “the dark millennium”. The reason for this is not fully understood, but it is likely due to the depletion of resources due to unfavourable climatic conditions. </p>
<p>Instead, large settlements of several thousand houses emerged further north in parts of what are now Moldova and Ukraine. Located on the western end of the forest steppe zone, these mega-sites were associated with the <a href="https://doi.org/10.1007/s10963-017-9105-8">Cucuteni-Trypillia culture</a>. </p>
<p>Here, during a period called the Eneolithic spanning from 5,200 to 6,500 years ago, the region around today’s Odesa became a “melting pot” of human interaction. Numerous cultural influences appear in the archaeological record, including the waning Copper Age cultures and the Cucuteni-Trypillia culture. </p>
<p>Interestingly, the resulting style of pottery and other artefacts at the mega-sites showed influences from two additional groups. First, from nearby groups that could be traced to the steppe region east of Odesa. Second, from the distant Maykop culture of the North Caucasus, a mountain range east of the Black Sea. </p>
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<a href="https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Many photos of jewellery, weapons, tools and pots shown on a white background." src="https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=931&fit=crop&dpr=1 600w, https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=931&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=931&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1170&fit=crop&dpr=1 754w, https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1170&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/537927/original/file-20230718-20840-oyfm8y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1170&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Characteristic jewellery, weapons, tools and pottery from the melting pot area around today’s Odesa. The pottery combines characteristics from numerous cultures of the area.</span>
<span class="attribution"><span class="source">I. Manzura (2020), History Carved by the Dagger: the Society of the Usatovo Culture in the 4th Millennium BC</span></span>
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<p>The steppe groups practised a different way of life, called nomadic pastoralism. Where farmers lived on and worked the same piece of land, nomadic pastoralists kept moving to find fresh pastures for their large herds of animals.</p>
<p>On top of this very different lifestyle, they also carried a distinct genetic profile called “steppe ancestry”.</p>
<h2>A surprising discovery</h2>
<p>By analysing the genomes of 18 ancient individuals from the Odesa region from this period, we could see genetic evidence of the many cultural influences observed by archaeologists. </p>
<p>In addition to the previously observed Copper Age ancestry, we detected new genetic contributions from individuals from the forest steppe regions, and the North Caucasus. This new ancestry and its appearance in western Europe had been uniquely associated with the spread of a later cultural group known as the Yamnaya. </p>
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Read more:
<a href="https://theconversation.com/how-a-handful-of-prehistoric-geniuses-launched-humanitys-technological-revolution-171511">How a handful of prehistoric geniuses launched humanity's technological revolution</a>
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<p>This was a huge surprise. We didn’t expect to see signs of this ancestry until at least 500 years later, when the Yamnaya arrived.</p>
<p>These findings show there was not only a cultural exchange between the different groups. There must have also been biological interactions of many genetically distinct people coming together in this contact zone as early as 5,400 to 6,500 years ago. </p>
<p>Due to this “melting pot” the Eneolithic was characterised by a number of innovations. Technologies such as wheels, wagon transportation and improved metal-working spread quickly into western Europe and Central Asia.</p>
<h2>A mosaic of ancestries</h2>
<p>We also analysed 21 individuals from the Early Bronze Age, approximately 4,000–5,300 years ago. In eight of these individuals we observed the expected westward expansion of steppe pastoralists, this time associated with <a href="https://doi.org/10.1038/nature14317">the Yamnaya culture</a>. </p>
<p>This final migration brought with it the last part of the modern Western European gene pool, likely emerging from the preceding period of contact and exchange that we identified. However, the remaining 13 individuals retained the genetic signature from the preceding Copper Age. These findings indicated a coexistence of these genetically distinct peoples. </p>
<p>Our study of genetic data over time reveals a highly dynamic picture of human prehistory in southeastern Europe. As more ancient DNA data becomes available, so too will more chapters of this story.</p><img src="https://counter.theconversation.com/content/210056/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Ancient DNA from Ukraine uncovers the earliest evidence of the arrival of the ‘steppe ancestry’ – the last piece of the modern Western European genetic puzzle.
Adam "Ben" Rohrlach, Mathematics Lecturer and Ancient DNA Researcher, University of Adelaide
Sandra Penske, PhD Student, Max Planck Institute for Evolutionary Anthropology
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/207593
2023-06-28T18:10:56Z
2023-06-28T18:10:56Z
English dialects make themselves heard in genes
<figure><img src="https://images.theconversation.com/files/534597/original/file-20230628-21-5cad3t.jpg?ixlib=rb-1.1.0&rect=289%2C118%2C4440%2C3103&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Conditions in rural England around the turn of the 20th century offer a case study for cultural evolution researchers.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/coming-home-from-the-marshes-1886-a-work-made-of-platinum-news-photo/1338669913">Heritage Images/Hulton Archive via Getty Images</a></span></figcaption></figure><p>If you need to hit a nail, what tool do you ask for? If you say “hammer,” do you pronounce the “<a href="https://www.bl.uk/british-accents-and-dialects/articles/phonological-variation-across-the-uk#:%7E:text=Above%20all%20he%20is%20a%20rhotic%20speaker">r</a>”? Do you drop the “<a href="https://www.bl.uk/british-accents-and-dialects/articles/social-variation-across-the-uk#:%7E:text=and%20happens.-,H%2Ddropping,-%E2%80%93%20the%20tendency%20to">h</a>”?</p>
<p>Different people pronounce the same English words in different ways. People learn which words to use and how to pronounce them as they’re learning to talk with family, friends and others in their community, so geographic patterns in these pronunciations can <a href="https://www.theguardian.com/science/2022/jul/31/north-south-english-dialects-language-pronunciation-study">persist over time</a>.</p>
<p>In England, pairs of words that mean similar things, like “sight” and “vision” or “yes” and “aye,” can reveal a rich history of language that is intertwined with the history of the place itself. Such words have their origins in <a href="https://education.nationalgeographic.org/resource/norman-conquest/">migrations and conquests</a> that took place during the Middle Ages. New words would sometimes coexist and sometimes displace one another.</p>
<p><a href="https://scholar.google.com/citations?user=06-OHeUAAAAJ&hl=en&oi=ao">Cultural evolution researchers</a> <a href="https://scholar.google.com/citations?user=vwQdgAYAAAAJ&hl=en&oi=ao">like us</a> know that it’s not just mountain ranges or oceans that can be barriers to interaction. Different people can share their technology, cuisines and ideas, but some tend to interact more often with those who share cultural similarities, <a href="https://doi.org/10.1146/annurev.soc.27.1.415">a behavior called homophily</a>.</p>
<p>This can be seen most clearly when cultural traditions lead people to marry people from the same community. Populations that tend to marry within their group because of <a href="https://doi.org/10.1186/1742-4755-6-17">social or economic forces</a>, including <a href="https://doi.org/10.1038/srep35837">religious</a> <a href="https://www.science.org/content/article/tracing-roots-jewishness-rev2">traditions</a> and <a href="https://www.nytimes.com/2017/07/17/health/india-south-asia-castes-genetics-diseases.html">social stratification</a>, have smaller gene pools, leading them to be more genetically similar to one another.</p>
<p>In addition to groups with distinctive marital practices, researchers have found relationships between genes and culture when studying groups that are <a href="https://doi.org/10.1371/journal.pgen.1003316">from different ethnicities</a> or <a href="https://doi.org/10.1073/pnas.94.15.7719">different regions of the world</a>. These similarities between genes and culture don’t imply that certain genetic variants are exclusive to these groups, or that genetics causes certain cultures to arise. Rather, the same people might be more likely to share genetics and language because of a common history, especially because of significant geographic or social barriers between groups.</p>
<p>Can smaller things, like the different dialects between neighboring villages, shape the genetic landscape of populations? In our <a href="https://doi.org/10.1002/ajpa.24789">new study</a>, we combined genetic and linguistic data sampled in England to study the effects of culture on genetics at smaller geographic scales than generally studied.</p>
<p>We examined this relationship between cultural and genetic variation across England. In places where people move often, the small correlations between language and genes can be lost because of how rapidly they change. Since Great Britain is an island, <a href="https://doi.org/10.1111/1468-0289.00221">few people entered its rural population</a> between the times of the Norman conquest in 1066 and the end of the 19th century, making it ideal for our analysis.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="two women and three children in 1956 collect water from a tub against a stone wall of a house" src="https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=493&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=493&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=493&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=620&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=620&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534599/original/file-20230628-19-htd5ou.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=620&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In the middle of the 20th century, interviewers recorded the ways rural people spoke.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/village-without-water-at-ruyton-xi-towns-shropshire-churns-news-photo/867461430">Bill Ellman/Mirrorpix via Getty Images</a></span>
</figcaption>
</figure>
<h2>Combining two sets of data</h2>
<p>Ideally, we could use a unified data set capturing information about the genetics and dialects of people living in a region. Unfortunately, no such data exists. Instead, we used data from two separate studies of people from approximately the same time and place. For our research, we focused on where the data sets overlapped in England.</p>
<p>For linguistic data, we relied on the <a href="https://dialectandheritage.org.uk/about/the-survey-of-english-dialects/">Survey of English Dialects</a>. Between 1950 and 1961, interviewers visited over 300 mostly rural places and asked people hundreds of questions about their daily lives. Their answers recorded the phrases, terms and sounds of local dialects of English. Each of these words can carry clues about where, or with whom, a person grew up.</p>
<p>The genetic data we used came from the <a href="https://www.peopleofthebritishisles.org/">People of the British Isles</a> project, an academic investigation of how much Britain’s historical events of conquest, war and migration are reflected in British genetics. The project sequenced DNA from more than 2,000 people in Great Britain and Northern Ireland. Researchers genotyped people whose grandparents who were born within 50 miles (80 kilometers) of each other, were largely rural, and were born in the late 19th century.</p>
<p>The People of the British Isles project found that most genotypes were not local to any one part of Great Britain <a href="https://doi.org/10.1038/nature14230">but were evenly distributed</a>. However, the historical movements of people to Great Britain left genetic marks: Compared with people in the rest of Great Britain, the genetics of those from the south of England were slightly more similar to those in France – a result of the Norman conquest a millennium ago – and the genetics of people in the former <a href="https://www.britannica.com/place/Danelaw">Danelaw</a> were slightly more similar to modern Danes – because of the settling of the region by Vikings and, later, Danes. These events resulted in groups of people with somewhat similar genetics, a phenomenon <a href="https://doi.org/10.1126/science.1078311">referred to as genetic clustering</a>.</p>
<p>We used features from the Survey of English Dialects to measure where neighboring towns spoke the most differently, which occurs at the borders between dialects. When people from neighboring towns speak the same dialect, we expect features of their language, such as whether the “r” is pronounced at the ends of words, to be similar. Conversely, if nearby towns speak different dialects, their language features will be more different.</p>
<p>Many of these dialect boundaries have long histories, such as that separating the English of the <a href="https://www.bl.uk/british-accents-and-dialects/articles/regional-voices-the-north-south-divide">North from that of the South of England</a>. Over time, <a href="https://www.theguardian.com/science/2022/jul/31/north-south-english-dialects-language-pronunciation-study">dialects can persist</a> in similar locations if geographic or cultural barriers influence how often and with whom people interact.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="1938 black and white photo of postman pushing bike up hill in village" src="https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=452&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=452&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=452&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=568&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=568&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534601/original/file-20230628-29-64o014.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=568&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rural life was more insular in the past.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-postmans-job-is-not-a-happy-one-when-the-snow-is-on-the-news-photo/3288430">Fox Photos/Hulton Archive via Getty Images</a></span>
</figcaption>
</figure>
<h2>The echo of sounds long gone</h2>
<p>We found greater genetic differences at the borders between dialects. Our results suggest that language, or some other aspect of culture, has limited how people interacted to some degree over the past thousand years. By limiting how often people started families with those from neighboring groups, cultural differences have maintained genetic evidence of the Norman conquest and other events from the Middle Ages.</p>
<p>This is the first time that information about linguistic dialects has been compared with modern genetic data within a population, particularly at such a granular level. Notably, people speaking different dialects have no obvious reason to avoid marrying one another, as would be expected from groups with specific marriage customs. Nevertheless, we find that even small-scale language differences, or other aspects of culture associated with these differences, can leave an impression on genes via people’s mating behaviors.</p>
<p>Even though people outside of Britain may think of a general “British accent,” the subtle differences among dialects seem to have parallels with the genetics of the region. This is in spite of the fact that the languages brought by people coming to England have since mixed and merged to produce the modern English language and today’s dialects.</p>
<p>The data used in our study represents the genetic landscape and dialects of the late 19th century; both have changed significantly since then. After the introduction of radio and television, dialects became more influenced by the cities around them. As a result, features of many English dialects in England, such as the pronunciation of “r” at the ends of syllables, have <a href="https://www.cam.ac.uk/research/news/cambridge-app-maps-decline-in-regional-diversity-of-english-dialects">become much less common</a>.</p>
<p>At the same time, immigrants from the former British Empire and elsewhere have brought a new influx of language. The cities in Great Britain have developed a set of new dialects rooted in the interactions among people from all ethnicities. As cultural barriers among groups fall away, small human interactions form the bridges that allow people to deemphasize differences and learn from one another.</p>
<p><em>This article has been updated to clarify which parts of the United Kingdom were included in the different data sets and the authors’ study.</em></p><img src="https://counter.theconversation.com/content/207593/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yakov Pichkar receives funding from the John Templeton Foundation (grant no. 62187). </span></em></p><p class="fine-print"><em><span>Nicole Creanza receives funding from the National Science Foundation and the John Templeton Foundation.</span></em></p>
People with a common history – often due to significant geographic or social barriers – often share genetics and language. New research finds that even a dialect can act as a barrier within a group.
Yakov Pichkar, Ph.D. Candidate in Biological Sciences, Vanderbilt University
Nicole Creanza, Assistant Professor of Biological Sciences, Vanderbilt University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/206232
2023-06-13T20:05:08Z
2023-06-13T20:05:08Z
Bones, the ‘Cave of the Monkeys’ and 86,000 years of history: new evidence pushes back the timing of human arrival in Southeast Asia
<figure><img src="https://images.theconversation.com/files/528694/original/file-20230528-27-d2uomq.JPG?ixlib=rb-1.1.0&rect=0%2C0%2C5184%2C3453&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Kira Westaway</span>, <span class="license">Author provided</span></span></figcaption></figure><p>In 2009, when our team first found a human skull and jaw bone in Tam Pà Ling Cave in northern Laos, some were sceptical of its origin and true age. </p>
<p>When we published a <a href="https://www.pnas.org/doi/full/10.1073/pnas.1208104109">timeline</a> in 2012 for the arrival of modern humans in mainland Asia around 46,000 years ago based on the Tam Pà Ling evidence, the sceptics remained.</p>
<p>In short, the site was given a bad rap. One of the most interesting caves in mainland Southeast Asia was frequently overlooked as a possible route on the accepted path of human dispersal in the region. </p>
<p>However, in <a href="https://www.nature.com/articles/s41467-023-38715-y">new research</a> published today in Nature Communications, we report more human remains found in Tam Pà Ling – and a more detailed and robust timeline for the site. This shows humans reached the region at least 68,000 years ago, and possibly as long as 86,000 years ago.</p>
<h2>Plenty of evidence, but hard to date</h2>
<p>Our team of Laotian, French, US and Australian researchers has been excavating at Tam Pà Ling for many years. You can see a detailed, interactive 3D scan of the site <a href="https://mq.pedestal3d.com/r/0DH2py28jD">here</a>.</p>
<p>As we dug, we found more and more evidence of <em>Homo sapiens</em> at earlier and earlier times. </p>
<p>First there was a finger bone, then roughly 2.5 metres deeper, a chin bone, then part of a rib. In total, eight pieces were found in only 4.5 metres of sediment – which may not sound like a lot, but is huge in archaeological terms.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing a cave in a rocky hill." src="https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=484&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=484&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=484&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=608&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=608&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531223/original/file-20230611-22144-nb009s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=608&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A cross-sectional view of the Tam Pà Ling cave, showing the location of the trench where remains were found.</span>
<span class="attribution"><a class="source" href="https://www.nature.com/articles/s41467-023-38715-y">Freidline et al. / Nature Communications</a></span>
</figcaption>
</figure>
<p>Surely, we thought, this would be enough for Tam Pà Ling to take its place among the early human arrival sites in Southeast Asia.</p>
<p>But a hurdle remained: the cave is hard to date. This has prevented its significance being recognised, and without a convincing timeline the cave’s evidence will not be included in the debate over early human movements.</p>
<h2>Many common dating methods can’t be used</h2>
<p>There are a few difficulties with dating Tam Pà Ling. </p>
<p>First, the human fossils cannot be directly dated as the site is a world heritage area and the fossils are protected by Laotian laws. </p>
<p>Second, there are very few animal bones and no suitable cave decorations, either of which might be used for dating.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo from inside a cave, looking up a rocky slope to daylight outside." src="https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531222/original/file-20230611-158977-iblgu4.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The wide, steep entrance to Tam Pà Ling channelled sediments and fossils into the cave over a long time period.</span>
<span class="attribution"><span class="source">Kira Westaway</span></span>
</figcaption>
</figure>
<p>And third, the entrance of the site is wide and steep. This means any charcoal found in the cave, which is useful for dating, may well have come from outside – so it has little relation to the age of the sediment inside.</p>
<p>This means the backbone of the timeline must be established by the dating of the sediment itself, using techniques such as luminescence dating.</p>
<h2>Signals in buried minerals</h2>
<p>Luminescence dating relies on a light-sensitive signal that builds up in buried sediment, resetting to zero when it is exposed to light.</p>
<p>This technique mainly uses two minerals: quartz and feldspar. </p>
<p>Quartz can only be used in the younger levels as it is limited by how much signal it can hold. In the deeper layers it can often underestimate the age, so in Tam Pà Ling we only used quartz to date the top three metres of the sediment. </p>
<p>For the lower levels (four to seven metres), we had to switch to dating using feldspar to fill in the gap in the age profile. Below six metres the feldspar grains started to weather and we had to resort to fine-grain dating, using tiny mineral grains all mixed together. </p>
<h2>Dating teeth</h2>
<p>Tam Pà Ling is relatively poor in animal evidence. Yet, eventually two teeth from a cow-like animal were unearthed at 6.5 metres deep that could be dated using two distinct techniques. </p>
<p>Uranium series dating works by measuring uranium, and the elements into which it transforms via radioactive decay, within the tooth. Electron spin resonance dating relies on measuring the number of electrons in tooth enamel. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/old-teeth-from-a-rediscovered-cave-show-humans-were-in-indonesia-more-than-63-000-years-ago-82075">Old teeth from a rediscovered cave show humans were in Indonesia more than 63,000 years ago</a>
</strong>
</em>
</p>
<hr>
<p>Each technique offers an individual numerical age for the fossil. By combining the two, we obtained robust direct dates, which can complement the luminescence chronology. </p>
<h2>A closer look at sediment</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of archaeologists at work in a cave." src="https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531224/original/file-20230611-150540-ohn2oi.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Archaeologists have returned to Tam Pà Ling regularly, steadily accumulating more evidence from a deep 7 m excavation.</span>
<span class="attribution"><span class="source">Kira Westaway</span></span>
</figcaption>
</figure>
<p>To make the dating as strong as possible, we used every technique we could, such as applying uranium series dating to a stalactite tip that had been buried in sediment. </p>
<p>We also began to support all our dating evidence with a very detailed analysis of the sediments to assess the origin of the fossils. </p>
<p>Micromorphology is a technique that examines sediments under a microscope to establish the integrity of the layers that buried the fossils. </p>
<p>This is a key component of the new chronology, as it helped establish that there was a fairly consistent accumulation of sediment layers over a long period. </p>
<p>By 2022, we had amassed an array of dating evidence that could be modelled to determine the exact age of each layer and the fossils they buried. </p>
<h2>A stop on the route of human dispersal</h2>
<p>Our updated chronology revealed humans were present in the vicinity of Tam Pà Ling Cave for roughly 56,000 years. It also confirmed that, far from reflecting a rapid dump of sediments, the site contains sediments that accumulated steadily over some 86,000 years.</p>
<p>The age of the lowest fossil, a fragment of a leg bone found seven metres deep, suggests modern humans arrived in this region between 86,000 and 68,000 years ago.</p>
<p>The evidence from Tam Pà Ling has pushed back the timing of <em>Homo sapiens</em> arrival in Southeast Asia. This suggests the mainland, along with the coastal and island locations, may have also been a viable dispersal route. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-fossil-tooth-places-enigmatic-ancient-humans-in-southeast-asia-179290">A fossil tooth places enigmatic ancient humans in Southeast Asia</a>
</strong>
</em>
</p>
<hr>
<p>Tam Pà Ling is just a stone’s throw from Cobra Cave, where we found a <a href="https://www.nature.com/articles/s41467-022-29923-z">tooth</a> some 150,000 years old belonging to a Denisovan, the now-extinct human relatives otherwise known only from remains found in Siberia and Tibet. This suggests the site may lie on a previously used dispersal route among hominins.</p>
<p>Tam Pà Ling continues to reveal pieces of the puzzle of the ancient human journey across the world. Only time will tell how many more it has in store.</p><img src="https://counter.theconversation.com/content/206232/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kira Westaway receives funding from Australian Research Council</span></em></p><p class="fine-print"><em><span>Meghan McAllister-Hayward receives funding from Flinders University College of Humanities, Arts and Social Sciences and the ARC Future Fellowship awarded to Associate Professor Mike Morley. </span></em></p><p class="fine-print"><em><span>Mike W Morley receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Renaud Joannes-Boyau receives funding from the Australian Research Council </span></em></p><p class="fine-print"><em><span>Vito C. Hernandez receives funding from the College of Humanities, Arts and Social Sciences of Flinders University, and the ARC Future Fellowship grant of Associate Professor Mike Morley.</span></em></p>
New evidence from contested Laos cave site shows humans reached Southeast Asia at least 68,000 years ago.
Kira Westaway, Associate Professor, School of Natural Sciences, Macquarie University
Meghan McAllister-Hayward, PhD Candidate
Mike W. Morley, Associate Professor, Flinders University
Renaud Joannes-Boyau, Associate Professor, Southern Cross University
Vito C. Hernandez, Geoarchaeologist and Postgraduate Research Scholar, Flinders University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/206200
2023-05-24T03:15:20Z
2023-05-24T03:15:20Z
Ancient humans may have paused in Arabia for 30,000 years on their way out of Africa
<figure><img src="https://images.theconversation.com/files/527894/original/file-20230524-20-w6g0dp.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Most scientists agree modern humans developed in Africa, more than 200,000 years ago, and that a great human diaspora across much of the rest of the world occurred between perhaps 60,000 and 50,000 years ago. </p>
<p>In new research <a href="https://www.pnas.org/doi/10.1073/pnas.2213061120">published</a> in Proceedings of the National Academies of Sciences, we have uncovered dozens of distinctive historical changes in the human genome to reveal a new chapter in this story. </p>
<p>Our work suggests there may have been a previously unknown phase of humanity’s great migration: an “Arabian standstill” of up to 30,000 years in which humans settled in and around the Arabian Peninsula. These humans slowly adapted to life in the region’s colder climate before venturing to Eurasia and beyond. </p>
<p>The legacy of these adaptations still lingers. Under modern conditions, many genetic changes from this period are linked to diseases including obesity, diabetes, and cardiovascular disorders. </p>
<h2>History in our genomes</h2>
<p>Since the first human genome was published in 2000, the amount of human genomic data available has grown exponentially. These rapidly growing datasets contain traces of key events in human history. Researchers have been actively developing new techniques to find those traces.</p>
<p>When ancient humans left Africa and moved around the globe, they likely met new environments and challenges. New pressures would have led to adaptation and genetic changes. These changes would subsequently have been inherited by modern humans.</p>
<p><a href="https://www.nature.com/articles/s41586-021-03244-5">Previous research</a> on genomic data shows ancient humans most likely left Africa and spread across the planet between 60,000 and 50,000 years ago. </p>
<p>However, we still don’t know much about genetic adaptations during this crucial time period. </p>
<h2>Ancient adaptation events</h2>
<p>Our team of evolutionary and medical researchers has shed new light on this period. By studying both ancient and modern genomes, we have shown genetic selection was probably an important facilitator of this ancient human diaspora.</p>
<p>Using ancient human genomes makes it possible to recover <a href="https://theconversation.com/ancient-dna-reveals-a-hidden-history-of-human-adaptation-193251">evidence of past events</a> in which specific genetic variants were strongly favoured over others and swept through a population. These “hard sweep” events are surprisingly rare in modern human genomes, most likely because their traces have been erased or distorted by subsequent mixing between populations.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ancient-dna-reveals-a-hidden-history-of-human-adaptation-193251">Ancient DNA reveals a hidden history of human adaptation</a>
</strong>
</em>
</p>
<hr>
<p>However, in <a href="https://www.nature.com/articles/s41559-022-01914-9">earlier work</a> we identified 57 regions in the human genome where an initially rare beneficial genetic variant effectively replaced an older variant in ancient Eurasian groups. </p>
<p>In our <a href="https://www.pnas.org/doi/10.1073/pnas.2213061120">new study</a>, we reconstructed the historical spread of these genetic variants. We also estimated the temporal and geographical origins of the underlying selection pressures. </p>
<p>Further, we identified the gene in each hard sweep region most likely to have been selected for. Knowing these genes helped us understand the ancient pressures that may have led to their selection.</p>
<h2>Coping with cold</h2>
<p>Our findings suggest early humans went through a period of extensive adaptation, lasting up to 30,000 years, before the big diaspora between 60,000 and 50,000 years ago. This period of adaptation was followed by rapid dispersal across Eurasia and as far as Australia. </p>
<p>We call this period the “Arabian standstill”. Genetic, archaeological and climatic evidence all suggest these ancient humans were most likely living in and around the Arabian Peninsula.</p>
<p><iframe id="8yMnX" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/8yMnX/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>The genetic adaptations involved parts of the genome related to fat storage, nerve development, skin physiology, and tiny hair-like fibres in our airways called cilia. These adaptations share striking functional similarities with those found in humans and other mammals living in the Arctic today. </p>
<p>We also detected similar functional similarities with previously identified human adaptive genes derived from historical mixing events with Neanderthals and Denisovans. These distant relatives of humans are also thought to have adapted to cold Eurasian climates. </p>
<p>Overall, these changes seem likely to have been driven by adaptation to the cool and dry climates in and around prehistoric Arabia between 80,000 and 50,000 years ago. The changes would also have prepared the ancient humans for the cold Eurasian climates they would eventually encounter.</p>
<h2>Old adaptations, modern diseases</h2>
<p>Many of these adaptive genes have links to modern diseases, including obesity, diabetes, and cardiovascular disorders. The adaptations around the human expansion from Africa may have established genetic variations that, under modern conditions, are associated with common diseases. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-found-traces-of-humanitys-age-old-arms-race-with-coronaviruses-written-in-our-dna-163254">We found traces of humanity's age-old arms race with coronaviruses written in our DNA</a>
</strong>
</em>
</p>
<hr>
<p>As we have suggested in <a href="https://theconversation.com/we-found-traces-of-humanitys-age-old-arms-race-with-coronaviruses-written-in-our-dna-163254">another study</a>, genes that were adaptive in the past might contribute to modern human susceptibility to various diseases. Identifying the genetic targets of historical adaptation events could help the development of therapeutic approaches and preventive measures for contemporary populations.</p>
<p>Our findings contribute to a new but growing literature highlighting the importance of adaptation in shaping human history. They also show the growing potential of evolutionary genetics for medical research.</p><img src="https://counter.theconversation.com/content/206200/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ray Tobler receives funding from Australian Research Council.</span></em></p><p class="fine-print"><em><span>Shane T Grey receives funding from NHMRC, ARC, MRFF, JDRF and NIH. </span></em></p><p class="fine-print"><em><span>Yassine Souilmi is supported by funding from the ARC and NHMRC.</span></em></p>
Genetic evidence reveals a long, previously unknown period of adaptation to cold climates in the history of ancient human migrations across the globe.
Ray Tobler, Postdoctoral fellow, Australian National University
Shane T Grey, Chair professor, Garvan Institute
Yassine Souilmi, Group Leader, Genomics and Bioinformatics, Australian Centre for Ancient DNA, University of Adelaide
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/179360
2022-06-27T12:25:01Z
2022-06-27T12:25:01Z
How many ice ages has the Earth had, and could humans live through one?
<figure><img src="https://images.theconversation.com/files/468859/original/file-20220614-17290-2cjvwa.jpg?ixlib=rb-1.1.0&rect=25%2C12%2C8601%2C5729&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">During ice ages, ice sheets like the one in Greenland have covered much of Earth's surface. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-greenland-ice-sheet-is-the-largest-ice-sheet-in-the-news-photo/1399203109">Thor Wegner/DeFodi Images via Getty Images</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>How many ice ages has the Earth had, and could humans live through one? – Mason C., age 8, Hobbs, New Mexico</strong></p>
</blockquote>
<p>First, what is an <a href="https://geology.utah.gov/map-pub/survey-notes/glad-you-asked/ice-ages-what-are-they-and-what-causes-them/">ice age</a>? It’s when the Earth has cold temperatures for a long time – millions to tens of millions of years – that lead to ice sheets and glaciers covering large areas of its surface. </p>
<p>We know that the Earth has had <a href="http://iceage.museum.state.il.us/content/when-have-ice-ages-occurred">at least five major ice ages</a>. The first one happened about 2 billion years ago and lasted about 300 million years. The most recent one started about 2.6 million years ago, and in fact, we are still technically in it. </p>
<p>So why isn’t the Earth covered in ice right now? It’s because we are in a period known as an “interglacial.” In an ice age, temperatures will fluctuate between colder and warmer levels. Ice sheets and glaciers melt during warmer phases, which are called interglacials, and expand during colder phases, which are called glacials.</p>
<p>Right now we are in the most recent ice age’s warm interglacial period, which began about 11,000 years ago.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/I4EZCy14te0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Earth’s climate goes through warming and cooling cycles that are influenced by gases in its atmosphere and variations in its orbit around the sun.</span></figcaption>
</figure>
<h2>What was it like during the ice age?</h2>
<p>When most people talk about the “ice age,” they are usually referring to the last glacial period, which began about 115,000 years ago and ended about 11,000 years ago with the start of the current interglacial period. </p>
<p>During that time, the planet was much cooler than it is now. At its peak, when ice sheets covered most of North America, the average global temperature was about <a href="https://www.smithsonianmag.com/smart-news/ice-age-temperature-science-how-cold-180975674/">46 degrees Fahrenheit</a> (8 degrees Celsius). That’s 11 degrees F (6 degrees C) cooler than the global annual average today.</p>
<p>That difference might not sound like a lot, but it resulted in most of North America and Eurasia being covered in ice sheets. Earth was also much drier, and <a href="https://www.usgs.gov/media/images/coastline-eastern-us-changesslowly">sea level was much lower</a>, since most of the Earth’s water was trapped in the ice sheets. <a href="https://education.nationalgeographic.org/resource/steppe">Steppes</a>, or dry grassy plains, were common. So were <a href="http://kids.nceas.ucsb.edu/biomes/savanna.html">savannas</a>, or warmer grassy plains, and deserts.</p>
<p>Many <a href="https://ucmp.berkeley.edu/quaternary/ple.html">animals present during the ice age</a> would be familiar to you, including brown bears, caribou and wolves. But there were also megafauna that went extinct at the end of the ice age, like <a href="https://uwaterloo.ca/earth-sciences-museum/resources/ice-age-mammals">mammoths, mastodons, saber-toothed cats</a> and <a href="https://www.livescience.com/56762-giant-ground-sloth.html">giant ground sloths</a>. </p>
<p>There are different ideas about <a href="https://samnoblemuseum.ou.edu/understanding-extinction/extinctions-in-the-recent-past-and-the-present-day/pleistocene-extinctions/">why these animals went extinct</a>. One is that humans hunted them into extinction when they came in contact with the megafauna.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scientist and workers gather around a jawbone and horns protruding out of the ground." src="https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468864/original/file-20220614-2525-72v0y4.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">Excavating a mastodon skeleton at Burning Tree Golf Course in Heath, Ohio, December 1989. The skeleton, found by workers who were digging a pond, was 90% to 95% complete and more than 11,000 years old.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/mF53eR">James St. John/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Wait, there were humans during the ice age?!</h2>
<p>Yes, people just like us lived through the ice age. Since our species, <em>Homo sapiens</em>, <a href="https://humanorigins.si.edu/evidence/human-fossils/species/homo-sapiens">emerged about 300,000 years ago in Africa</a>, we have spread around the world. </p>
<p>During the ice age, some populations remained in Africa and did not experience the full effects of the cold. Others moved into other parts of the world, including the cold, glacial environments of Europe. </p>
<p>And they weren’t alone. At the beginning of the ice age, there were other species of hominins – a group that includes our immediate ancestors and our closest relatives – throughout Eurasia, like the <a href="https://humanorigins.si.edu/evidence/human-fossils/species/homo-neanderthalensis">Neanderthals</a> in Europe and the mysterious <a href="https://www.newscientist.com/definition/denisovans/">Denisovans</a> in Asia. Both of these groups seem to have gone extinct before the end of the ice age. </p>
<p>There are lots of ideas about how our species survived the ice age when our hominin cousins did not. Some think that it has to do with how adaptable we are, and how we <a href="https://www.discovermagazine.com/planet-earth/how-humans-survived-the-ice-age">used our social and communication skills and tools</a>. And it appears that humans didn’t hunker down during the ice age. Instead they moved into new areas. </p>
<p>For a long time it was thought that humans did not enter North America until after the ice sheets started to melt. But <a href="https://www.nps.gov/whsa/learn/nature/fossilized-footprints.htm">fossilized footprints</a> found at <a href="https://www.nps.gov/whsa/index.htm">White Sands National Park</a> in New Mexico show that humans have been in North America since at least 23,000 years ago – close to the peak of the last ice age.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/179360/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Denise Su does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The Earth has had at least five major ice ages, and humans showed up in time for the most recent one. In fact, we’re still in it.
Denise Su, Associate Professor, Arizona State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/168426
2021-09-23T18:00:41Z
2021-09-23T18:00:41Z
Fossil footprints prove humans populated the Americas thousands of years earlier than we thought
<figure><img src="https://images.theconversation.com/files/422440/original/file-20210921-25-kgjgkh.jpeg?ixlib=rb-1.1.0&rect=0%2C274%2C1004%2C507&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Are these the footprints of the first-known American teen?</span> <span class="attribution"><span class="source">Matthew Robert Bennett</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Our species began migrating out of Africa around <a href="https://www.science.org/doi/10.1126/science.1199113">100,000 years ago</a>. Aside from Antarctica, the Americas were the last continents humans reached, with the early pioneers crossing the now-submerged <a href="https://www.nationalgeographic.org/photo/bering-land-bridge/">Bering land bridge</a> that once connected eastern Siberia to North America. </p>
<p>At times throughout the <a href="https://www.britannica.com/science/Pleistocene-Epoch">Pleistocene ice age</a>, which ended 10,000 years ago, large ice sheets covered much of Europe and North America. The water locked in these ice sheets lowered the sea level, allowing people to walk the bridge from Asia through the Arctic to Alaska. But during the peak of the last glacial cycle, their path south into the Americas was blocked by a continental-wide ice sheet.</p>
<p>Until now, scientists believed humans only travelled south into the Americas when this ice barrier began to melt – at the earliest, <a href="https://www.nature.com/articles/485030a">16,500 years ago</a>. But together with our colleagues, we have <a href="https://www.science.org/doi/10.1126/science.abg7586">discovered</a> a set of fossil footprints that suggest humans first set foot on the continent thousands of years earlier.</p>
<figure class="align-right ">
<img alt="two fossil footprints" src="https://images.theconversation.com/files/422441/original/file-20210921-25-14vvp7y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/422441/original/file-20210921-25-14vvp7y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=990&fit=crop&dpr=1 600w, https://images.theconversation.com/files/422441/original/file-20210921-25-14vvp7y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=990&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/422441/original/file-20210921-25-14vvp7y.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=990&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/422441/original/file-20210921-25-14vvp7y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1244&fit=crop&dpr=1 754w, https://images.theconversation.com/files/422441/original/file-20210921-25-14vvp7y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1244&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/422441/original/file-20210921-25-14vvp7y.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1244&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The fossil footprints.</span>
<span class="attribution"><span class="source">Matthew Robert Bennett</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These footprints, unearthed at White Sands National Park in New Mexico, were made by a group of teenagers, children and the occasional adult, and have been dated to the height of the last glacial maximum, some 23,000 years ago. That makes them potentially the oldest evidence of our species in the Americas. </p>
<p>Our findings support the idea that humans were present in the southern part of North America before the last glacial peak – a theory that has so far been based on disputed and potentially unreliable evidence.</p>
<h2>Step change</h2>
<p>There are literally tens of thousands of fossil footprints at White Sands. Together, they tell <a href="https://theconversation.com/fossil-footprints-the-fascinating-story-behind-the-longest-known-prehistoric-journey-147520">stories</a> of how prehistoric humans interacted with extinct Ice Age megafauna, such as Columbian mammoths and <a href="https://theconversation.com/how-to-hunt-a-giant-sloth-according-to-ancient-human-footprints-95344">giant ground sloths</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-hunt-a-giant-sloth-according-to-ancient-human-footprints-95344">How to hunt a giant sloth – according to ancient human footprints</a>
</strong>
</em>
</p>
<hr>
<p>The tracks were deposited around the margins of a large wetland – perhaps a lake after the rainy season, but at other times more like a patchwork of water bodies. Until now, the problem had been dating these footprints. We knew they were imprinted before the megafauna became extinct, but not precisely when. </p>
<p>This changed in September 2019 when the team found tracks with undisturbed sediment above and below them. Within that sediment were layers containing hundreds of seeds of the common ditch grass <em>Ruppia cirrhosa</em>. These seeds, when radiocarbon dated, would reveal the age of the footprints themselves. Analysis revealed the seeds range in age from 21,000 to 23,000 years old, suggesting humans made repeated visits to the site over at least two millennia.</p>
<figure class="align-center ">
<img alt="Some dark brown seeds" src="https://images.theconversation.com/files/422443/original/file-20210921-15-169uoe8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/422443/original/file-20210921-15-169uoe8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=383&fit=crop&dpr=1 600w, https://images.theconversation.com/files/422443/original/file-20210921-15-169uoe8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=383&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/422443/original/file-20210921-15-169uoe8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=383&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/422443/original/file-20210921-15-169uoe8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=482&fit=crop&dpr=1 754w, https://images.theconversation.com/files/422443/original/file-20210921-15-169uoe8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=482&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/422443/original/file-20210921-15-169uoe8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=482&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Some of the seeds that we extracted from the footprints.</span>
<span class="attribution"><span class="source">Matthew Robert Bennett</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The White Sands footprints provide unequivocal evidence that people were in the Americas at the height of the last glacial maximum, rather than some time after, as was previously thought. That’s a big deal for our understanding of the peopling of the Americas and the genetic composition of indigenous Americans. </p>
<p>Using the DNA of modern indigenous Americans, scientists have worked out that their ancestors arrived from Asia in several waves, some of which became genetically isolated. The cause of this isolation is not clear. Now, our new footprint evidence provides an explanation, suggesting that the earliest Americans were isolated south of the North American ice sheet, only to be joined by others when that sheet melted.</p>
<p>Our discovery may also reopen speculation about other archaeological sites in the Americas. One of them is <a href="https://doi.org/10.1038/s41586-020-2509-0">Chiquihuite Cave</a> in Mexico. Archaeologists recently claimed that evidence from this cave suggests humans occupied the Americas around 30,000 years ago – 7,000 years before people left the White Sands footprints.</p>
<p>But the Chiquihuite Cave findings are disputed by some, as stone tools can be difficult to interpret and tool-like stones can form via natural processes. Stone tools can also move between layers of sediment and rock. Fossil footprints can’t. They are fixed on a bedding plane, and so provide more reliable evidence of exactly when humans left them.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="modern footprints bordering ancient ones." src="https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/422447/original/file-20210921-23-1uj9b7l.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">On the left, modern shoeprints; on the right, footprints millennia old.</span>
<span class="attribution"><span class="source">Matthew Robert Bennett</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Teenage kicks</h2>
<p>We tend to picture our ancestors engaged in life-or-death struggles – forced to battle the elements simply to survive. Yet the White Sands evidence is suggestive of a playful, relatively relaxed setting, with teenagers and children spending time together in a group.</p>
<p>This is perhaps not that surprising. Children and teenagers are more energetic and playful than adults and therefore leave more traces. Adults tend to be more economical in their movement, leaving fewer tracks. </p>
<figure class="align-center ">
<img alt="An illustration of prehistoric man and mammoths" src="https://images.theconversation.com/files/422602/original/file-20210922-16-fhamca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/422602/original/file-20210922-16-fhamca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=297&fit=crop&dpr=1 600w, https://images.theconversation.com/files/422602/original/file-20210922-16-fhamca.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=297&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/422602/original/file-20210922-16-fhamca.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=297&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/422602/original/file-20210922-16-fhamca.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=373&fit=crop&dpr=1 754w, https://images.theconversation.com/files/422602/original/file-20210922-16-fhamca.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=373&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/422602/original/file-20210922-16-fhamca.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=373&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">What White Sands might have looked like 23,000 years ago.</span>
<span class="attribution"><a class="source" href="http://www.davidebonadonna.it/">Davide Bonadonna</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>But another interpretation of this new footprint evidence is that the teenagers were part of the workforce in these early bands of hunter-gatherers. It’s possible that the tracks were left by young people fetching and carrying resources for their prehistoric parents.</p>
<p>In any case, the people that left their tracks on White Sands were some of the earliest known American teens. Set in stone, their footprints pay tribute to their forebears, who we now know walked the long land bridge into the Americas millennia earlier than what was commonly believed.</p><img src="https://counter.theconversation.com/content/168426/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The New Mexico findings could rewrite the history of human migration to the Americas.
Matthew Robert Bennett, Professor of Environmental and Geographical Sciences, Bournemouth University
Sally Christine Reynolds, Principal Academic in Hominin Palaeoecology, Bournemouth University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/167050
2021-09-01T20:10:52Z
2021-09-01T20:10:52Z
Research reveals humans ventured out of Africa repeatedly as early as 400,000 years ago, to visit the rolling grasslands of Arabia
<figure><img src="https://images.theconversation.com/files/418801/original/file-20210901-13-u6hxli.jpg?ixlib=rb-1.1.0&rect=22%2C16%2C1352%2C740&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Eleanor Scerri</span>, <span class="license">Author provided</span></span></figcaption></figure><p>If you stood in the middle of the Nefud Desert in central Arabia today, you’d be confronted on all sides by enormous sand dunes, some rising more than 100 meters from the desert floor. </p>
<p>The few scraggly bushes make poor browse for the herds of goats and camels that eke out a living in this harsh environment. But this wasn’t always the case.</p>
<p>Our research published today in <a href="https://www.nature.com/articles/s41586-021-03863-y">Nature</a> shows that in repeated pulses over the past 400,000 years, the Nefud Desert landscape received monsoon rains that resulted in rolling grasslands, flowing rivers and large lakes home to thousands of wild donkeys, antelopes and hippos.</p>
<p>Humans also inhabited these green corridors as they made their way out of Africa, only to disappear when conditions deteriorated again. </p>
<p>Among other findings, we present the oldest dated evidence for hominins in Arabia, in the form of stone tools dated to about 400,000 years ago. The Homininae subfamily is the group of humans of which <em>Homo sapiens</em> is the sole survivor. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=292&fit=crop&dpr=1 600w, https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=292&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=292&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=367&fit=crop&dpr=1 754w, https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=367&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/418793/original/file-20210901-15-1rcoh1e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=367&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A 400,000 year ‘handaxe’ stone tool from Khall Amayshan 4.</span>
<span class="attribution"><span class="source">Palaeodeserts Project (photo by Ian Cartwright)</span></span>
</figcaption>
</figure>
<h2>Early movements out of Africa</h2>
<p>Today Arabia is one of the world’s driest places, and was long thought to have played little role in human prehistory. </p>
<p>While the rich and long-studied Levant and the Mediterranean regions were considered critical for the dispersal of people out of Africa, it was thought most humans would have avoided places like the Arabian “Empty Quarter” — due to the harshness of its environmental conditions. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/418773/original/file-20210831-19-1s6hphj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Nefud Desert today.</span>
<span class="attribution"><span class="source">Julien Louys</span></span>
</figcaption>
</figure>
<p>But detailed scientific investigations over the past few decades have been slowly changing these ideas. A rich stone tool culture has now been recovered from the surfaces of many ancient and dried out lakebeds in Southwest Asia. </p>
<p>However, because these were from isolated beds — often hundreds of kilometres apart — and restricted to surface scatters, it was difficult to determine who had left these tools, when, and where they came from.</p>
<p>In collaboration with the Heritage Commission of the Saudi Ministry of Culture and other Saudi colleagues, our international team of researchers has been working in Saudi Arabia, Southwest Asia’s largest country, for the past decade. </p>
<p>We have recorded and studied a wealth of stone tools and animal fossils emerging from the sands and ancient lakebeds. And we’ve made some startling discoveries. </p>
<p>We recovered a <em>Homo sapiens</em> finger bone, among other fossils, from an ancient Saudi Arabian lakebed known as <a href="https://www.nature.com/articles/s41559-018-0518-2">Al Wusta</a>. These remains were dated to 85,000 years ago. This finding shows modern humans had made it out <a href="https://theconversation.com/our-fossil-finger-discovery-points-to-earlier-human-migration-in-arabia-94670">of Africa at least 20,000 years before</a> the genetic evidence indicates we left. </p>
<p>It has been thought (and many still believe) <em>Homo sapiens</em> only left Africa about 50-65,000 years ago. Our finger bone finding challenges this view, as do other discoveries - including from Madjedbebe in Australia. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/buried-tools-and-pigments-tell-a-new-history-of-humans-in-australia-for-65-000-years-81021">Buried tools and pigments tell a new history of humans in Australia for 65,000 years</a>
</strong>
</em>
</p>
<hr>
<p>What happened to the group of people from Al Wusta remains unknown. They may have moved further into Asia, or retreated back to Africa. Or they may have become locally extinct.</p>
<h2>A green Arabia</h2>
<p>We also report a series of archaeological sites associated with multiple lakes across two locations which tell the story of human prehistory going back 400,000 years. The first of these locations, Khall Amayshan 4, is a depression located between large sand dunes covering 60,000 square metres. </p>
<p>In this single depression we found individual lakebeds dated back to 55,000, 100,000, 200,000, 300,000 and 400,000 thousand years ago. And each of the five lake phases is represented by its own unique archaeological signature.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/418774/original/file-20210831-29-9oaf0z.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Aerial view of Khall Amayshan 4 showing the series of ancient lakebeds. See the two small, white 4WDs on the left for scale.</span>
<span class="attribution"><span class="source">Julien Louys</span></span>
</figcaption>
</figure>
<p>Today different populations around the world can be identified by their cultures, which include the tools they use, how they’re made and how they use them. Think chopsticks across Asia and forks in Europe, for example. </p>
<p>These tools are passed on to successive generations, even if those generations move from their point of origin. The way people made and used stone tools in the past also reflected patterns of cultural inheritance. </p>
<p>So by studying and comparing the stone tools from Arabia with those from surrounding regions, we can find out not just when people were living and moving through the region, but also where their ancestors had moved from and how they changed as they moved.</p>
<p>The most striking thing we found was that each assemblage of stone tools recovered from each ancient lakebed was very different from the others. </p>
<p>Our detailed examination of the lakebeds and the mammal fossils they preserved, including from hippos, clearly pointed to how much wetter, greener and more productive each of those phases were compared to the region today. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/418796/original/file-20210901-13-2w4jz1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Antelope teeth eroding from an ancient lakebed in the Nefud Desert.</span>
<span class="attribution"><span class="source">Julien Louys</span></span>
</figcaption>
</figure>
<p>The different technologies associated with each green phase indicate there was no long-term continuity in the populations in the area. Instead, different populations, perhaps even different species of hominin, were moving in and out with each phase. </p>
<p>At the Jubbah Oasis around 150 km east of Khall Amayshan 4, two further sites – Jebel Qattar 1 and Jebel Umm Sanman 1 – filled in the last of the gaps in the timeline. These sites presented different stone tools dating to around 200,000 and 75,000 years ago, also associated with green phases. </p>
<p>Each of these phases occurs during wetter climatic periods, which are wetter due to the northern movements of the monsoon, bringing increased rainfall to the desert. Once the climate shifted back, however, conditions became arid again and humans and other fauna disappeared from Arabia. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/prehistoric-desert-footprints-are-earliest-evidence-for-homo-sapiens-on-arabian-peninsula-146445">Prehistoric desert footprints are earliest evidence for Homo sapiens on Arabian Peninsula</a>
</strong>
</em>
</p>
<hr>
<p>Our findings reveal the intimate association between early human migrations and patterns of climate change — wherein different groups of humans repeatedly made it out of Africa when conditions became favourable. </p>
<p>And this happened long before the dispersal event of 50-65,000 years ago, which finally saw their descendents permanently colonise other regions.</p>
<p>Yet dozens of questions remain. Were some of these migrations from northern Neanderthals? What became of these different populations? Where did they go? Could some have made it to Southeast Asia and hence to Australia? </p>
<p>The human story won’t be told completely until we explore more long-neglected areas, much like our ancestors once did.</p><img src="https://counter.theconversation.com/content/167050/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Louys receives funding from The Australian Research Council and the Leakey Foundation</span></em></p><p class="fine-print"><em><span>Gilbert Price receives funding from The Australian Research Council and the Leakey Foundation.</span></em></p><p class="fine-print"><em><span>Huw Groucutt receives funding from the Max Planck Society.</span></em></p><p class="fine-print"><em><span>Michael Petraglia receives funding from the European Research Council and the Max Planck Society. </span></em></p>
The new work presents the oldest dated evidence for hominins in Arabia, in the form of an ancient handaxe tool uncovered from the Nefud Desert.
Julien Louys, Deputy Director, Australian Research Centre for Human Evolution, Griffith University
Gilbert Price, Lecturer in Palaeontology, The University of Queensland
Huw Groucutt, Group leader of Max Planck 'Extreme Events' group., Max Planck Institute of Geoanthropology
Michael Petraglia, Professor of Archaeology, Max Planck Institute of Geoanthropology
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/130106
2020-10-30T12:49:16Z
2020-10-30T12:49:16Z
Cahokian culture spread across eastern North America 1,000 years ago in an early example of diaspora
<figure><img src="https://images.theconversation.com/files/365994/original/file-20201028-19-11trta4.jpg?ixlib=rb-1.1.0&rect=481%2C618%2C3859%2C2421&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cahokia's mound-building culture flourished a millennium ago near modern-day St. Louis.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/st-louis-missouri-from-cahokia-mounds-royalty-free-image/825340730">JByard/iStock via Getty Images Plus</a></span></figcaption></figure><p>An expansive city flourished almost a thousand years ago in the bottomlands of the Mississippi River across the water from where St. Louis, Missouri stands today. It was one of the greatest pre-Columbian cities constructed north of the Aztec city of Tenochititlan, at present-day Mexico City.</p>
<p>The people who lived in this now largely forgotten city were part of a monument-building, corn-farming culture. No one knows what its inhabitants named this place, but today archaeologists call the city <a href="https://cahokiamounds.org/">Cahokia</a>. </p>
<p>Excavations show it was home to thousands of families. The city held hundreds of earthen mounds that supported council houses, homes for social elites, tombs for powerful leaders and <a href="https://doi.org/10.1179/2327427113Y.0000000005">reminders of lunar alignments</a>. In addition, archaeologists have discovered a <a href="https://www.pbs.org/video/cahokias-celestial-calendar-woodhenge-jizxuu/">Woodhenge</a> at Cahokia – a circular celestial observatory made of large wooden posts.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="white stone projectile points" src="https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=790&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=790&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=790&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=992&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=992&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366506/original/file-20201029-19-1arc5tw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=992&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Typical Cahokian projectiles excavated at the Mill Cove Complex in Florida.</span>
<span class="attribution"><span class="source">Keith Ashley</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Archaeologists call the pre-Columbian societies that lived in the Mississippi River Valley region “Mississippian cultures.” These people stretched as far west as Oklahoma, north to Wisconsin, south to Mississippi and Louisiana, and east to Florida and North Carolina. Though broadly similar, it’s unlikely these people thought of themselves as a unified political body.</p>
<p>A complex question in American archaeology hinges on how these cultures arose and the ways in which they shared ideas, goods and people.</p>
<p>Did the Cahokians create Mississippian culture as they moved outward from their homeland, bringing their artifacts and ideas with them? Or did Cahokians spread across the Midwest and Southeast, meeting new communities and sharing ideas along the way, eventually helping form Mississippian culture through a kind of melting-pot process? Recently, my colleagues <a href="https://www.easternct.edu/faculty-directory/baires.html">Sarah Baires</a>, <a href="https://utoledo.academia.edu/MelissaBaltus">Melissa Baltus</a> and <a href="https://illinois.academia.edu/ElizabethWattsMalouchos">Elizabeth Watts Malouchos</a> <a href="https://scholar.google.com/citations?user=1M1FPzYAAAAJ&hl=en&oi=ao">and I</a> have contributed to <a href="https://link.springer.com/journal/10816/volumes-and-issues/27-1">new</a> <a href="https://upf.com/book.asp?id=9781683400820">research</a> investigating what it meant to be a Cahokian and Mississippian.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="outdoor archaeological dig" src="https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365985/original/file-20201028-13-18ztoci.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Archaeology students excavate Cahokian and Mississippian sites to learn more about the culture they left behind.</span>
<span class="attribution"><span class="source">Jayur Mehta</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Striking out from Cahokia</h2>
<p>Like cities today, Cahokia was a diverse place inhabited by groups of people with different histories, diverging values and varying ideas. So when people left the city, they likely had a variety of reasons.</p>
<p>Early in Cahokia’s history, movements into and out of the city may have been <a href="https://doi.org/10.1177/1469605318763626">tied to religious gatherings</a> while later migrations out of the city may have been <a href="https://doi.org/10.1179/0093469013Z.00000000054">related to political change</a>. While there is some evidence for <a href="https://doi.org/10.1007/s10816-019-09431-z">conflict</a> and potential for <a href="https://www.jstor.org/stable/20622439">drought</a> in the region, archaeologists have no conclusive evidence that those were the ultimate causes for people leaving the city. After all, some people <a href="https://doi.org/10.1017/aaq.2019.103">continued to live there</a>. </p>
<p>Whatever their motives, as Cahokian citizens spread out from St. Louis and migrated throughout the woodlands east of the Mississippi River, they carried their culture with them. Sometimes these were unique artifacts, like <a href="https://doi.org/10.32873/unl.dc.zea.1241">particular ceramics typical of their region</a>. But they also brought with them specific cultural constructs, like their beliefs in the <a href="http://dx.doi.org/10.1080/0734578X.2017.1378986">ordering of the cosmos</a> and relationships between the upper and lower worlds. </p>
<h2>Recreating parts of home</h2>
<p>During the early days of Cahokia, around 1050, emissaries from the city traveled north to sites in what is now Wisconsin, spurring the local creation of platform mounds and sculpted landscapes similar to those in the Cahokian heartland. These places were <a href="https://doi.org/10.7183/0002-7316.80.2.260">religious shrines or outposts</a> that likely inspired the construction of more Cahokian style earthen mounds in the north. </p>
<p>At sites like these, Cahokian citizens embraced new places and new environments, often developing unique relationships with the communities into which they immigrated. We know this through archaeological excavations that found Cahokian-style households, site layouts, pottery and more integrated into these new communities.</p>
<p>It looks like they were remembering their homeland, adopting local practices while keeping their own traditions alive. In modern settings, this phenomenon is often called a diaspora – an enclave of immigrants living among local populations with their own practices and beliefs that hearken back to where they came from.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=825&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=825&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=825&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1037&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1037&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365990/original/file-20201028-23-1hf3kjf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1037&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Top: 1894 hand-drawn map of the Carson Mounds site. Bottom: 2018 plan view drawing of excavated structures at the site.</span>
<span class="attribution"><span class="source">Top: Cyrus Thomas Bottom: Benny Roberts and John Connaway</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>For instance, at the <a href="https://en.wikipedia.org/wiki/Carson_Mounds">Carson site</a> <a href="https://www.youtube.com/watch?v=xYRspQhRd8c&ab_channel=jayurmehta">in north Mississippi</a>, far downriver from the Cahokian homeland, Cahokian migrants recreated familiar built environments. They constructed long, rectangular and semi-subterrenean houses at Carson <a href="https://doi.org/10.1007/s10816-019-09432-y">that looked like home</a>.</p>
<p>Decades of excavations in north Mississippi suggest that the Cahokians likely observed other people and their <a href="https://egrove.olemiss.edu/etd/1570/">above-ground square houses</a> as they migrated southward, but chose to build in ways that evoked homeland – much as how a Hindu temple in Texas still maintains the <a href="https://www.baps.org/Global-Network/North-America/Houston.aspx">spires, domes and craftwork</a> of India. It took another one or two hundred years for the square house style to be built at Carson.</p>
<h2>Blending lifestyles with those they met</h2>
<p>In northeast Florida, Cahokians encountered <a href="https://doi.org/10.1007/s10816-019-09439-5">local communities of St. Johns people</a>, mound builders of sites like Grant, Shields and Mt. Royal. Archaeologists call the tools and architecture of the two groups’ shared history the <a href="https://www.researchgate.net/profile/Keith_Ashley/publication/304497371_Toward_an_Interpretation_of_the_Mill_Cove_Complex/links/577169df08ae842225ac256d/Toward-an-Interpretation-of-the-Mill-Cove-Complex.pdf">Mill Cove Complex</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="stone artifact" src="https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=440&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=440&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=440&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=553&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=553&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365983/original/file-20201028-17-12a9dgi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=553&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Cahokian emissaries carried distinctive tools like this Burlington chert drill.</span>
<span class="attribution"><span class="source">Jayur Mehta</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>For instance, Cahokians may have sought unique local knowledge about the emergence of the Sun and Moon from the ocean – <a href="https://www.academia.edu/download/58221704/Pauketat_2017_oxfordhb-9780198788218-e-81.pdf">celestial alignments were important for Cahokians</a>, and this would have been an unobserved phenomenon in the Mississippi River Valley. In exchange, Cahokian emissaries brought with them a kind of rock known as Burlington chert, a familiar resource for making <a href="https://doi.org/10.5744/florida/9780813049366.003.0014">their unique tri-lobed</a> <a href="http://www.projectilepoints.net/Points/Cahokia.html">projectile points</a>.</p>
<p>Excavations in the area revealed long-nosed god maskettes made of copper; these artifacts are found at only 20 or so sites across the <a href="https://www.google.com/books/edition/_/55h7hrf-ET0C?hl=en&gbpv=1&pg=PA61">Southeast and Midwest</a>, all of which have a Cahokian presence. These <a href="https://americanindian.si.edu/static/exhibitions/infinityofnations/woodlands/243506.html">masks</a> may have been part of a hero narrative that was also depicted in <a href="https://www.jstor.org/stable/20708122">rock art</a> and narrated by Siouxan speaking groups whose traditional lands encompassed much of the Upper Midwest.</p>
<p>Farther north, Cahokians created other new, hybridized styles with local populations. </p>
<p>For example, during Cahokia’s emergence around 1050, nearby villages in the uplands of southern Illinois went through their own social transformation; they adopted some aspects of early Cahokian culture while retaining cultural and architectural <a href="https://www.jstor.org/stable/20708178">features of their own</a>.</p>
<p>This can be seen in artifacts found at the Halliday site, located in southern Illinois approximately 30 kilometers southeast of Cahokia; excavations have found nonlocal pottery types from Indiana and northern Mississippi, Tennessee and Arkansas, alongside pottery typical of Cahokia. People at Halliday were also eating slightly different foods than at other nearby sites, suggesting they maintained culinary traditions of their remote homelands. </p>
<p>Archaeologists have also found evidence that these upland villages eventually adopted a Cahokian building method that placed a prefabricated wall directly into a trench. But it didn’t happen immediately. They stuck with placing single posts into the ground to create building walls for houses from 1050 to 1350, emphasizing villagers’ choice to maintain some of their <a href="https://doi.org/10.1179/sea.2011.30.1.008">pre-Cahokian traditional practices in the face of social change</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="sideview of grass-covered Monks Mound on a sunny day" src="https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365997/original/file-20201028-13-1tdzyfp.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">Monks Mound at Cahokia is one of the largest earthen mounds in North America.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/cahokia-mounds-monks-mound-sideview-royalty-free-image/511786885">Denise Panyik-Dale/Moment Open via Getty Images</a></span>
</figcaption>
</figure>
<h2>Similarities to today</h2>
<p>In each place where Cahokians remade themselves, they contended with local communities, as well as their individual memories of their homeland.</p>
<p>Cahokian migrants made houses that mimicked those at home; they built according to celestial alignments from home; and in diasporic settings, they made iconographic designs honoring mythic heroes from their homeland. </p>
<p>Because Cahokians never ceased making their homeland wherever they spread – albeit in unique ways in new environments – we believe it makes sense to think of Cahokian and Mississippian culture not as one monolithic entity with just one perspective, but instead, a multitude of voices that together signified something greater. </p>
<p>The broader anthropological implication of our Cahokian research is the reminder it provides across the centuries that migration and identity are an ongoing process by which individuals and communities make and remake themselves, all while remembering their homeland and adapting to a new one. This process describes the complexities of living in the diaspora, and it is as relevant today as it was a thousand years ago.</p>
<p>[<em>The Conversation’s science, health and technology editors pick their favorite stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-favorite">Weekly on Wednesdays</a>.]</p><img src="https://counter.theconversation.com/content/130106/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jayur Mehta received funding from the Mississippi Department of Archives and History for parts of this research. </span></em></p>
Five centuries before Columbus arrived, migrants were spreading across North America, carrying their culture with them and mixing with those they encountered in new places.
Jayur Mehta, Assistant Professor of Anthropology, Florida State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/130669
2020-09-29T12:31:30Z
2020-09-29T12:31:30Z
Archaeologists determined the step-by-step path taken by the first people to settle the Caribbean islands
<figure><img src="https://images.theconversation.com/files/360064/original/file-20200925-22-vgu7h0.jpg?ixlib=rb-1.1.0&rect=300%2C84%2C4533%2C3076&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What route did the first settlers to colonize the islands of the Caribbean take?</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/caribbean-royalty-free-image/132280669">M.M. Swee/Moment via Getty Images</a></span></figcaption></figure><p>For the millions of people around the world who live on islands today, a plane or boat can easily enough carry them to the mainland or other islands.</p>
<p>But how did people in the ancient past first make it to distant islands they couldn’t even see from home? Many islands around the world can be reached only by traveling hundreds or even thousands of miles across open water, yet nearly all islands that people live on were settled by between 800 to 1,000 years ago.</p>
<p><a href="https://scholar.google.com/citations?user=cVLYtvoAAAAJ&hl=en&oi=ao">Archaeologists</a> <a href="https://scholar.google.com/citations?user=o60SujYAAAAJ&hl=en&oi=ao">like</a> <a href="https://scholar.google.com/citations?user=tTV6YEoAAAAJ&hl=en&oi=ao">us</a> <a href="https://scholar.google.com/citations?hl=en&user=ZMMqNV4AAAAJ">want</a> to understand why people would risk their lives to reach these far-off places, what kinds of boat and navigational methods they used, and what other technologies they invented to make it. Islands are important places to study because they hold clues about human endurance and survival in different kinds of environments.</p>
<p>One of the most interesting places to study these processes is the Caribbean, the only region of the Americas where people settled an archipelago with some islands not visible from surrounding areas. Despite more than a century of research, there are still many questions about the origins of the first Caribbean people, when they migrated and what routes they took. My colleagues and I recently reanalyzed archaeological data collected over 60 years to answer these fundamental questions.</p>
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<h2>Settling the islands one by one</h2>
<p>Based on the discovery of unique stone tools and food remains such as shells and bones, archaeologists have a general understanding that <a href="https://doi.org/10.1179/2055557115Y.0000000010">people first spread throughout the Caribbean</a> in a series of migrations that probably began at least 7,000 years ago and likely originated from northern South America.</p>
<p><a href="http://www.uapress.ua.edu/product/On-Land-and-Sea,1478.aspx">Amerindians paddled between islands</a> in dugout canoes and were remarkably adept at open-water travel. Archaeologists don’t know what inspired people to first colonize the Caribbean islands, but we do know they brought plants and animals from the mainland, like manioc and oppossum, to help ensure their survival. </p>
<p>There are two main ideas about what happened. For decades, the prevailing notion was that people migrated from South America into the Antilles in a south-to-north “stepping-stone” pattern. Because the islands stretch in a gentle arc from Grenada all the way up to Cuba in the northwest – <a href="http://www.uapress.ua.edu/product/Archaeology-and-Geoinformatics,114.aspx">with many largely visible from one to the next</a> – this would seem to provide a convenient path for early settlers.</p>
<p>This hypothesis, however, has been challenged by evidence that <a href="https://doi.org/10.1086/320012">some of the earliest sites are in the northern islands</a>. Analyses of wind and ocean currents suggest that it was actually easier to travel directly between South America and the northern Caribbean before moving in a southerly direction. Researchers call this proposal of a north-to-south migration the “southward route” hypothesis.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="archeologists excavating with the sea in the background" src="https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/358882/original/file-20200918-14-1487jzo.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">For decades, archaeologists have been excavating artifacts on these islands.</span>
<span class="attribution"><span class="source">Scott Fitzpatrick</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Revisiting previous scientists’ date data</h2>
<p>Figuring out which model for settling the Caribbean best fits the evidence depends on being able to assign accurate dates to human activity preserved in the archaeological record. To do this, researchers need a lot of reliable dates from many different sites throughout the islands to establish how, when and from where people landed.</p>
<p>Archaeologists typically use <a href="https://theconversation.com/explainer-what-is-radiocarbon-dating-and-how-does-it-work-9690">a technique called radiocarbon dating</a> to figure out how old an artifact is. When an organism dies, it stops producing carbon and its remaining carbon decays at a fixed rate of time – archaeologists say “death starts the clock.” By measuring the amount of carbon left in the organism and then performing a few additional calculations, scientists are left with a probable age range for when that organism died.</p>
<p>Archaeologists often date things like food remains, charcoal from cooking hearths or wood in the building where they are found. If archaeologists date shells found in a trash heap, they can tell, usually within a range of 25 to 50 years or so, when that shellfish was harvested for a meal.</p>
<p>We recently <a href="https://doi.org/10.1126/sciadv.aar7806">reevaluated about 2,500 radiocarbon dates</a> from hundreds of archaeological sites on more than 50 Caribbean islands. </p>
<p>Archaeologists have been radiocarbon dating findings in the Caribbean since the 1950s – when the radiocarbon technique was first discovered. But dating methods and the standards scientists follow have improved dramatically since then. Part of our job was to see if each of the 2,500 radiocarbon dates available would meet today’s standards. Dates that did not meet those standards were thrown out, leaving us with a smaller database of only the most reliable times for human activity.</p>
<h2>Determining where people lived first</h2>
<p>By statistically analyzing these remaining dates, we confirmed that Trinidad was the first Caribbean island settled by humans, at least 7,000 years ago. However, Trinidad is so close to South America that only simple – or even no – boats were needed to get there.</p>
<p>After Trinidad, the oldest settlements occurred between 6,000 and 5,000 years ago in the northern Caribbean on the large islands of the Greater Antilles: Cuba, Puerto Rico and Hispaniola. Reaching them would have required crossing passages of water where no islands were visible to the naked eye, although navigators rely on other wayfinding techniques – like current, cloud patterns, seeing birds fly in a certain direction – to know if land is out there. By around 2,500 years ago, people had spread out to settle other islands in the northern Lesser Antilles, including Antigua and Barbuda.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="map of Caribbean showing order in which islands were settled, from north to south" src="https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/358878/original/file-20200918-14-619act.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Thousands of years after Trinidad, Cuba, Puerto Rico and Hispaniola were settled, colonists reached islands in the northern Antilles, bypassing islands in the southern Lesser Antilles, depicted with green SRH arrows for ‘southern route hypothesis.’ The stepping-stone model, depicted with SS arrow, is refuted by the new analysis.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1126/sciadv.aar7806">'Reevaluating human colonization of the Caribbean using chronometric hygiene and Bayesian modeling,' M. F. Napolitano et al, Science Advances, Dec. 18, 2019</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Based on these data, the patterns of initial settlement of the Caribbean are most consistent with the southward route hypothesis. </p>
<p>Around 1,800 years ago, a new wave of people also moved from South America into the Lesser Antilles, colonizing many of the remaining uninhabited islands. About 1,000 years later, their descendants moved into the smaller islands of the Greater Antilles and Bahamian archipelago. This is when Jamaica and the Bahamas were settled for the first time.</p>
<p>Our research findings also support the widely held view that environment played a significant role in how and when islands were settled.</p>
<p>Archaeologists know that once people settled islands, they frequently moved between them. Not all islands are the same, and some offered more or better resources than others. For example, in the Bahamas and the Grenadines, the primary <a href="https://doi.org/10.1353/crb.2012.0030">way to access freshwater</a> is by digging wells; there are no streams or springs. Some islands <a href="https://doi.org/10.1016/j.jasrep.2016.08.033">lacked clay for making pottery</a>, which was important for cooking and storing food. People may have also traveled to different islands to access preferred fishing or hunting spots or seek out marriage partners.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>Strong seasonal winds and currents facilitated travel between islands. That’s also probably one of the reasons why Caribbean people never developed the sail or other seafaring technologies that were used in the Pacific, Mediterranean and North Atlantic around the same time. Dugout canoes crossed between South America and the islands just fine.</p>
<p>Interpretations of past human behavior at archaeological sites are anchored by radiocarbon dates to study change over time. For archaeologists, it’s important to periodically take another look at the data to make sure that the narratives built on those data are reliable. Our review of the radiocarbon record for the Caribbean allowed us to show – with increased accuracy – the ways in which the region was first colonized by people, how they interacted and moved between islands, and how their societies developed following initial colonization.</p><img src="https://counter.theconversation.com/content/130669/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew F Napolitano is a PhD Candidate at the University of Oregon. </span></em></p><p class="fine-print"><em><span>Jessica Stone is an affiliated researcher with the Department of Anthropology at the University of Oregon.</span></em></p><p class="fine-print"><em><span>Robert DiNapoli is a Postdoctoral Research Associate in Harpur College at Binghamton University and an affiliated researcher with the Department of Anthropology at the University of Oregon.</span></em></p><p class="fine-print"><em><span>Scott Fitzpatrick is a Professor of Archaeology and Associate Director of the Museum of Natural and Cultural History at the University of Oregon.</span></em></p>
Did people settle these islands by traveling north from South America, or in the other direction? Reanalyzing data from artifacts discovered decades ago provides a definitive answer.
Matthew F. Napolitano, Ph.D. Candidate in Archaeology, University of Oregon
Jessica Stone, Affiliated Researcher in the Department of Anthropology, University of Oregon
Robert DiNapoli, Postdoctoral Research Associate in Archaeology, Binghamton University, State University of New York
Scott Fitzpatrick, Professor of Anthropology + Associate Director, Museum of Natural and Cultural History, University of Oregon
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/146763
2020-09-27T19:59:17Z
2020-09-27T19:59:17Z
White supremacists believe in genetic ‘purity’. Science shows no such thing exists
<p>Far-right white supremacist ideology is on the rise in Europe, <a href="https://www.nature.com/articles/s41599-020-00546-3">North America</a> and <a href="https://www.abc.net.au/news/2020-02-24/asio-director-general-mike-burgess-neo-nazi-threat-rising/11994178">Australia</a>. It appeals to a <a href="https://www.aspistrategist.org.au/the-difficulties-in-overcoming-the-white-supremacist-phenomenon/">racist notion</a> whereby many white supremacists see themselves as members of a “pure” race that is at risk of dilution and contamination. </p>
<p>Science does not support the idea of pure races with ancient origins. In the past few years, genetic sequencing of ancient and modern humans and related species has given us a flood of new information about how human populations have evolved.</p>
<p>The evidence reveals a history of ongoing genetic mingling, due to interbreeding between different populations and even species. Humans from different groups had children together, and even with Neanderthals and members of other now-extinct hominin species.</p>
<p>This mingling occurred constantly in the long process of human migration across the globe. Europeans inhabit one region of a large genetic continuum and are no more or less “pure” than any other population.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-believers-in-white-genocide-are-spreading-their-hate-filled-message-in-australia-106605">How believers in 'white genocide' are spreading their hate-filled message in Australia</a>
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<h2>From Africa to the world</h2>
<p>The <a href="https://www.the-scientist.com/features/genetics-steps-in-to-help-tell-the-story-of-human-origins-67871">genetic history of humanity</a> begins in what we now know as Africa. The exact location (or locations) of the first anatomically modern humans is debated, but there is a consensus they lived south of the Sahara desert between 100,000 and 200,000 years ago. </p>
<p>A group or groups of these early humans migrated out of Africa and into the Middle East, as we now know it, some time between 50,000 and 70,000 years ago. Next, some went east into Asia while others headed west into Europe. </p>
<p>At some point, the wandering humans <a href="https://www.the-scientist.com/magazine-issue/infographic--history-of-ancient-hominin-interbreeding-66319">met and bred with Neanderthals</a>. These now-extinct hominins had left Africa many thousands of years earlier. </p>
<p>Modern Asians and Europeans still carry <a href="https://www.pnas.org/content/116/31/15327">genetic signatures</a> of Neanderthals, while sub-Saharan Africans do not. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-dna-ancestry-testing-can-change-our-ideas-of-who-we-are-114428">How DNA ancestry testing can change our ideas of who we are</a>
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<p>The humans that migrated east into Asia also met and bred with other extinct species of hominins, including at least <a href="https://doi.org/10.1016/j.cell.2018.02.031">two major injections of genes</a> from a group we call Denisovans. </p>
<p>Early modern humans almost certainly bred with other ancient hominins as well, because interspecies breeding was likely common. The remains of a girl with a <a href="https://www.the-scientist.com/news-opinion/girl-had-a-denisovan-dad-and-neanderthal-mom-64674">Neanderthal mother and Denisovan father</a> have recently been discovered. Another recent study has shown some Neanderthals too <a href="https://science.sciencemag.org/content/369/6511/1653">carried traces of human DNA</a>.</p>
<h2>Genetic diversity leads to greater fitness</h2>
<p>Genetic diversity, as measured by a metric called heterozygosity, <a href="https://pubmed.ncbi.nlm.nih.gov/27654910/">decreases with geographic distance from Africa</a>. Higher heterozygosity is generally associated with greater genetic fitness for survival. </p>
<p>From this perspective it could be argued that, when the humans who walked away from Africa lost genetic diversity through living in small groups, they also lost genetic fitness. By the same argument, interbreeding between populations increases fitness. </p>
<p>In fact, Europeans probably benefited from picking up some Neanderthal DNA: these genes are thought to have <a href="https://www.the-scientist.com/features/neanderthal-dna-in-modern-human-genomes-is-not-silent-66299">diversified their immune systems</a> and may have contributed to their lighter pigmentation. </p>
<p>Humans who migrated west into Europe continued to <a href="https://www.nature.com/articles/nature21347">meet and breed with other human populations</a>. </p>
<p>Another wave of humans from what we call Anatolia (roughly modern-day Turkey) followed the initial spread of humans into Europe. The Yamnaya population from what we now know as the Russian steppe migrated west into Europe between 3,000 and 5,000 years ago. In fact, little genetic trace remains of the first human inhabitants of Europe, as they were continually supplanted by others.</p>
<p>Even the Roman civilisation, considered to be one of the historical foundations of European identity, was home to great genetic variety. A <a href="https://science.sciencemag.org/content/366/6466/708.abstract">recent study</a> looked at the genomes of 127 people from 29 sites across the past 10,000 years. It found an initial wave of hunter-gatherers had been supplanted by an Anatolian population, and during the age of Imperial Rome (27 BC to 300 AD) there were significant introductions of genes from what is now Iran and the eastern Mediterranean.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/vikings-were-never-the-pure-bred-master-race-white-supremacists-like-to-portray-84455">Vikings were never the pure-bred master race white supremacists like to portray</a>
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</p>
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<h2>Even Vikings were diverse</h2>
<p>Blonde-haired, blue-eyed northern Europeans are considered by many white supremacists as the ideal of racial purity. They are epitomised historically by the Vikings. </p>
<p>However, the reality was different. A <a href="https://www.nature.com/articles/s41586-020-2688-8">recent study</a> of 442 human genomes from archaeological sites across Europe and Greenland found substantial ancestry from elsewhere in Europe entering Scandinavia during the Viking Age. In fact, Vikings were more likely to have dark hair than modern Scandinavians.</p>
<p>In short, the idea of a pure white race has no basis in genetics. Lightly pigmented skin, hair and eyes are simply an adaptation to northern European climates (and represent an inferior adaptation in equatorial regions). These features exist in a background of countless other genetic influences borrowed from many populations, old and new.</p>
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<strong>
Read more:
<a href="https://theconversation.com/how-science-has-been-abused-through-the-ages-to-promote-racism-50629">How science has been abused through the ages to promote racism</a>
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</p>
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<img src="https://counter.theconversation.com/content/146763/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dennis McNevin is the Director of the Genetic Ancestry Lab. He has received funding from the Australian Research Council, the Australian Institute of Nuclear Science and Engineering (AINSE), the US Army International Technology Center - Pacific, ANU Connect Ventures and the AMP Tomorrow Fund.</span></em></p>
Genetic studies show mingling between populations has been the norm throughout human history.
Dennis McNevin, Professor of Forensic Genetics, University of Technology Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/145072
2020-09-20T07:44:57Z
2020-09-20T07:44:57Z
Why South Africa’s new plan to fortify its borders won’t stop irregular migration
<figure><img src="https://images.theconversation.com/files/358433/original/file-20200916-16-1jgpbnk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Zimbabwean migrants illegally cross Into South Africa.
</span> <span class="attribution"><span class="source">John Moore/Getty Images</span></span></figcaption></figure><p>South Africa has just passed a <a href="https://www.gov.za/documents/border-management-authority-act-2-2020-english-sepedi-21-jul-2020-0000">new law</a> in response to growing concerns in the country about its porous borders. The socioeconomic and <a href="https://www.timeslive.co.za/news/south-africa/2019-08-14-porous-borders-biggest-threat-to-domestic-security-in-sa-new-spy-boss/">security dangers</a> posed by having large numbers of undocumented migrants have become key political issues in the country in recent times.</p>
<p>It’s <a href="https://ewn.co.za/2018/09/17/fact-check-are-the-11-million-undocumented-migrants-in-sa">difficult to ascertain</a> how many undocumented migrants there are in the country, leading to <a href="https://africacheck.org/reports/do-5-million-immigrants-live-in-s-africa-the-new-york-times-inflates-number/">exaggerated estimates</a>. According to Statistics South Africa figures from 2011, legal migrants were about 4.2% of the total population, or about <a href="http://www.statssa.gov.za/publications/Report-03-01-79/Report-03-01-792011.pdf">2.1 million people</a>. Over 75% came from the African continent, with the majority (68%) from within the Southern African Development Community (SADC) region. Over 45% of those from the SADC region were Zimbabweans. </p>
<p>The new law provides for the establishment of a <a href="https://www.gov.za/sites/default/files/gcis_document/202007/43536gon799.pdf">Border Management Authority</a>. Its primary function is to provide integrated border law enforcement. Its core functions include the governance and management of the lawful movement of people and goods within the border law enforcement areas and at ports of entry. It’ll work with other arms of government and relevant stakeholders in the discharge of border law <a href="https://www.gov.za/sites/default/files/gcis_document/202007/43536gon799.pdf">enforcement functions</a>.</p>
<h2>Why the change</h2>
<p>Migration and immigration are not efficiently managed at the moment, being undertaken by several entities. These include the Department of Home Affairs, South African Revenue Service, the Defence Force and the State Security Agency.</p>
<p>The functions and roles of these and other organs of state have been reconfigured. They will now basically fall on committees providing advice to the new agency on, inter alia, politics, security, defence and economy.</p>
<p>It is envisioned that the new agency and stronger policing will secure the porous borders, stop undocumented migration and enhance legitimate trade. But a closer reading of the new Act, particularly Chapter 6, shows that there is a strong move towards the militarisation of the country’s borders. This approach, which is similar to what European countries have implemented, is bound to fail in curbing undocumented migration. Undocumented migration is the crossing of borders without meeting immigration requirements.</p>
<h2>Militarisation and securitarisation</h2>
<p>Border militarisation involves the deployment of, among others, military technologies, equipment and <a href="https://rgs-ibg.onlinelibrary.wiley.com/doi/pdf/10.1111/tran.12115#:%7E:text=In%20contrast%20to%20claims%20of,into%20new%20spaces%20and%20arenas">personnel</a> to protect borders.</p>
<p>Border securitisation involves stringent immigration requirements as well as the reinforcement of the physical border, by for example, <a href="https://gizmodo.com/5-european-countries-have-built-border-fences-to-keep-o-1731065879">erecting walls or fences</a>.</p>
<p>In the case of South Africa, this will, among other things, entail the deployment of border guards who have powers to arrest and detain anybody deemed to have transgressed the new law. The border guards will have extensive powers. They will, for example, be empowered to search any person, premise, goods and vehicles as well as question any person about any matter related to the passage of people, goods or vehicles through a port of entry or <a href="https://www.gov.za/sites/default/files/gcis_document/202007/43536gon799.pdf">across the borders</a>. </p>
<p>This has parallels with other parts of the world. Examples include the European Union (EU) borders between Morocco and <a href="https://beatingborders.wordpress.com/2015/06/17/the-militarisation-of-the-european-borders-the-daily-terror-in-morocco/">Spain at Ceuta and Melilla</a>, where the objective is to keep migrants and refugees out, particularly those from Africa. </p>
<p>This involves the use of security technologies so sophisticated that they can <a href="https://www.law.ox.ac.uk/research-subject-groups/centre-criminology/centreborder-criminologies/blog/2017/05/treacherous">sense the heartbeat</a> of a border jumper. </p>
<h2>Lessons from elsewhere</h2>
<p>Nation states are entitled to secure their borders. Indeed, they are constitutionally bound to uphold their territorial sovereignty. But the militarisation of borders and securitisation of migration have always failed to stop irregular migration. </p>
<p>This can be seen in the case of the EU where they have failed to stop migrants from <a href="https://www.hrw.org/news/2016/12/06/impact-externalization-migration-controls-rights-asylum-seekers-and-other-migrants">crossing into Europe</a>.</p>
<p>Instead, the migrants have been led to find alternative ways to cross the border. I expect the same thing to happen in the case of South Africa. </p>
<p>No single country can effectively address the problem of irregular migration on its own in the southern African setting. Beefing up security at borders through military and security strategies is not the answer. An effective response lies in a regional approach to the management of migration and its root causes.</p>
<h2>Regional approach to illegal migration</h2>
<p>Such an approach should recognise that migration is a multidimensional phenomenon in terms of its causes, patterns, settings and consequences. </p>
<p>The 16 member states of the <a href="https://www.sadc.int/member-states/">Southern African Development Community</a> should jointly deal with the issue of undocumented migration through a regional migration mechanism which promotes free human mobility. </p>
<p>The <a href="https://www.sadc.int/files/8613/5292/8378/Declaration__Treaty_of_SADC.pdf">Declaration and Treaty of the SADC of 1992</a> and the subsequent <a href="https://www.sadc.int/files/9513/5292/8363/Protocol_on_Facilitation_of_Movement_of_Persons2005.pdf">SADC Protocol on the Facilitation of Movement of Persons</a> provide a good starting point for the region to formulate a regional migration management architecture that enables unlimited migration between member states. </p>
<p>The declaration and treaty commit the SADC to promoting regional integration and free human mobility. The protocol on the <a href="https://www.sadc.int/files/9513/5292/8363/Protocol_on_Facilitation_of_Movement_of_Persons2005.pdf">movement of persons</a>, which is not yet in full force, is a move in this direction.</p>
<p>Its main objective is to develop policies aimed at the progressive elimination of obstacles to the movement of people in the SADC region and within member states. It calls for the harmonisation of respective national laws in fulfilment of <a href="https://www.sadc.int/files/9513/5292/8363/Protocol_on_Facilitation_of_Movement_of_Persons2005.pdf">this objective</a>.</p>
<p>I posit that undocumented migration occurs because of stringent immigration regimes which force people to resort to such illegal acts as <a href="https://www.tandfonline.com/doi/abs/10.1080/15562948.2019.1570416">smuggling people across borders</a>. Differently stated, if there were free movement between countries in the region, the issue of undocumented and irregular migration would not arise. </p>
<p>This raises the related question of what nation states should do in the absence of a regional migration governance mechanism. In other words, should countries like South Africa stop improving the safety and management of their borders? </p>
<p>By all means countries should maintain their territorial integrity. But in an African setting, the historical context of borders and migration matters. </p>
<p>Africa’s borders were drawn arbitrarily by colonial powers, often separating people who had always lived together. These contiguous borders have <a href="https://theconversation.com/southern-africas-porous-borders-pose-a-problem-for-containing-the-coronavirus-135386">always been ignored and breached</a>. Thus, no amount of border militarisation and securitisation can stop such irregular migration.</p>
<h2>Addressing causes of irregular migration</h2>
<p>The multifaceted nature of migration in the SADC region requires the regional body to also address the issues which uproot people from their countries. These include bad governance and human rights abuses. </p>
<p>For example, if the SADC had responded swiftly and appropriately to the crisis in Zimbabwe in the 2000s, when that country embarked on questionable political programmes with regional political and economic ramifications, Zimbabweans would not have been forced to migrate in such great numbers to South Africa for economic reasons.</p>
<p>The SADC should have collectively leaned on the Zimbabwean government to stop human rights abuses. Instead, only the late Zambian president Levy Mwanawasa openly criticised the Zimbabwean government and called on the SADC <a href="https://www.reuters.com/article/us-zimbabwe-sadc/zambian-president-calls-zimbabwe-sinking-titanic-idUSL2140021620070321">to help address the country’s economic and political problems</a>. This never happened. </p>
<p>The Zimbabwean crisis continues unabated two decades later, leading many people to continue to flee to South Africa, some of them swimming across the <a href="https://www.sabcnews.com/sabcnews/smuggling-at-beit-bridge-border-continues-despite-r37-million-fence/">crocodile infested Limpopo River</a>. This shows that nothing can stop irregular migration – short of addressing its root causes, over and above a regional migration management approach. Given that most migrants in South Africa are from the SADC countries, with over 45% coming from Zimbabwe, it makes sense to deal with the issue of migration within the SADC first, before addressing those from other parts of Africa.</p><img src="https://counter.theconversation.com/content/145072/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Inocent Moyo does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The militarisation of borders and securitisation of migration have always failed to stop irregular migration.
Inocent Moyo, Senior Lecturer and Head of Department of Geography and Environmental Studies, University of Zululand
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/139458
2020-09-15T19:28:35Z
2020-09-15T19:28:35Z
Ancient DNA is revealing the genetic landscape of people who first settled East Asia
<figure><img src="https://images.theconversation.com/files/352993/original/file-20200814-22-dg3488.jpg?ixlib=rb-1.1.0&rect=310%2C222%2C3016%2C2074&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pulverized ancient bone can provide DNA to scientists for analysis.</span> <span class="attribution"><span class="source">Xin Xu Institute of Vertebrate Paleontology and Paleoanthropology</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>The very first human beings originally emerged in Africa before <a href="https://doi.org/10.1002/evan.21455">spreading across Eurasia</a> about 60,000 years ago. After that, the story of humankind heads down many different paths, some more well-studied than others.</p>
<p>Eastern regions of Eurasia are home to approximately 2.3 billion people today – roughly 30% of the world’s population. Archaeologists know <a href="https://doi.org/10.1016/j.quaint.2011.02.017">from fossils</a> <a href="https://doi.org/10.1126/science.aat8824">and artifacts</a> that modern humans have occupied <a href="https://doi.org/10.1038/nature23452">Southeast Asia for 60,000 years</a> and East Asia for 40,000 years.</p>
<p>But there’s a lot left to untangle. Who were the people who first came to these regions and eventually developed agriculture? Where did different populations come from? Which groups ended up predominant and which died out?</p>
<p>Ancient DNA is helping to answer some of these questions. By sequencing the genomes of people who lived many millennia ago, <a href="https://scholar.google.com/citations?user=3sRfg2sAAAAJ&hl=en&oi=ao">scientists like me</a>
are starting to fill in the picture of how Asia was populated.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Ancient skull without bottom jaw" src="https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353009/original/file-20200814-20-otal1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Well-preserved DNA from ancient bones holds clues about how human beings spread into East Asia.</span>
<span class="attribution"><span class="source">Wei Gao, Institute of Vertebrate Paleontology and Paleoanthropology</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Analyzing ancient genomes</h2>
<p>In 2016, I joined Dr. Qiaomei Fu’s Molecular Paleontology Lab at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences in Beijing. Our challenge: Resolve the history of humans in East Asia, with the help of collaborators who were long dead – ancient humans who lived up to tens of thousands of years ago in the region. </p>
<p>Members of the lab extracted and sequenced ancient DNA using human remains from archaeological sites. Then Dr. Fu and I used computational genomic tools to assess how their DNA related to that of previously sequenced ancient and present-day humans.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="map where aDNA samples were excavated in Asia" src="https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/357984/original/file-20200914-24-1frozem.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tianyuan Man, from near present-day Beijing, and Hòabìnhian people, from present-day Laos and Malaysia, represent two very old lineages that are distinct from today’s East Asians.</span>
<span class="attribution"><span class="source">Map © OpenStreetMap contributors, modified by The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>One of our sequences came from ancient DNA extracted from the <a href="https://www.pnas.org/content/110/6/2223">leg bones</a> of the Tianyuan Man, a <a href="https://doi.org/10.1016/j.cub.2017.09.030">40,000-year-old individual</a> discovered near <a href="https://whc.unesco.org/en/list/449/">a famous paleoanthropological site</a> in western Beijing. One of the earliest modern humans found in East Asia, his genetic sequence marks him as an early ancestor of today’s Asians and Native Americans. That he lived where China’s current capital stands indicates that the ancestors of today’s Asians began placing roots in East Asia as early as 40,000 years ago. </p>
<p>Farther south, <a href="https://doi.org/10.1126/science.aat3628">two 8,000- to 4,000-year-old Southeast Asian hunter-gatherers</a> from Laos and Malaysia associated with the Hòabìnhian culture have DNA that, like the Tianyuan Man, shows they’re early ancestors of Asians and Native Americans. These two came from a completely different lineage than the Tianyuan Man, which suggested that many genetically distinct populations occupied Asia in the past. </p>
<p>But no humans today share the same genetic makeup as either Hòabìnhians or the Tianyuan Man, in both East and Southeast Asia. Why did ancestries that persisted for so long vanish from the gene pool of people alive now? Ancient farmers carry the key to that answer. </p>
<h2>DNA carries marks of ancient migrations</h2>
<p>Based on plant remains found at archaeological sites, scientists know that <a href="https://www.sciencedaily.com/releases/2015/12/151214084754.htm">people domesticated millet</a> in northern China’s Yellow River region about 10,000 years ago. Around the same time, people in southern China’s Yangtze River region <a href="https://doi.org/10.1073/pnas.1308942110">domesticated rice</a>.</p>
<p>Unlike in Europe, plant domestication began locally and was not introduced from elsewhere. The process took thousands of years, and societies in East Asia grew increasingly complex, with the rise of the <a href="https://doi.org/10.1146/annurev-anthro-091908-164513">first dynasties</a> around 4,000 years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="map showing migration of ancient people north from Yellow River area and south from Yangtze River area" src="https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/357986/original/file-20200914-18-z19zh1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rice farmers, possibly from around the Yangtze River, moved south into Southeast Asia, while millet farmers from around the Yellow River moved north into Siberia.</span>
<span class="attribution"><span class="source">Map © OpenStreetMap contributors, modified by The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>That’s also when rice cultivation appears to have spread from its origins to areas farther south, including lands that are today’s Southeast Asian countries. DNA helps tell the story. When rice farmers from southern China expanded southward, they introduced not only their farming technology but also their genetics to local populations of Southeast Asian hunter-gatherers. </p>
<p>The overpowering influx of their DNA ended up swamping the local gene pool. Today, <a href="https://doi.org/10.1126/science.aat3628">little trace of hunter-gatherer ancestry</a> <a href="https://doi.org/10.1126/science.aat3188">remains in the genes of people</a> who live in Southeast Asia. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Excavation of human skeleton" src="https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=333&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=333&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=333&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=419&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=419&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353002/original/file-20200814-24-czv093.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=419&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The skeleton of a person who lived about 8,700 years ago in Xiaogao, Shandong, China near the Yellow River. This individual’s northern East Asian ancestry can be found in the remains of people who lived up into the eastern steppes of Siberia.</span>
<span class="attribution"><span class="source">Jianfeng Lang, Shandong University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Farther north, <a href="https://doi.org/10.1038/s41586-019-1279-z">a similar story played out</a>. Ancient Siberian hunter-gatherers show little relationship with East Asians today, but later Siberian farmers are closely related to today’s East Asians. Farmers from northern China moved northward into Siberia bringing their DNA with them, leading to a sharp decrease in prevalence of the previous local hunter-gatherer ancestry.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scientist in protective gear pipetting under a hood" src="https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353000/original/file-20200814-14-1aipm61.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">Professor Qiaomei Fu, head of the Molecular Paleontology Lab at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, prepares samples for ancient DNA extraction.</span>
<span class="attribution"><span class="source">Institute of Vertebrate Paleontology and Paleoanthropology</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Past populations were more diverse than today’s</h2>
<p>Genetically speaking, today’s East Asians are not very different from each other. A lot of DNA is needed to start genetically distinguishing between people with different cultural histories.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Folded up ancient skeleton being excavated" src="https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=868&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=868&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=868&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1091&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1091&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353004/original/file-20200814-18-mdsmzw.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1091&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This individual, who lived about 8,300 years ago on Liang island in the Taiwan Strait, has the southern ancestry found in inhabitants of coastal mainland southern China.</span>
<span class="attribution"><span class="source">Hunglin Chiu, Institute of Anthropology, National Tsinghua University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>What surprised Dr. Fu and me was how different the DNA of various ancient populations were in China. <a href="https://doi.org/10.1126/science.aba0909">We</a> <a href="https://doi.org/10.1101/2020.03.25.004606">and</a> <a href="https://doi.org/10.1038/s41467-020-16557-2">others</a> found shared DNA across the Yellow River region, a place important to the development of Chinese civilization. This shared DNA represents a northern East Asian ancestry, distinct from a southern East Asian ancestry <a href="https://doi.org/10.1126/science.aba0909">we found in coastal southern China</a>. </p>
<p>When we analyzed the DNA of people who lived in coastal southern China 9,000-8,500 years ago, we realized that already by then much of China shared a common heritage. Because their <a href="http://www.kaogu.cn/en/Research_work/Excavation_Report/2018/0122/60804.html">archaeology</a> and <a href="https://doi.org/10.1038/s41598-018-35426-z">morphology</a> was different from that of the Yellow River farmers, we had thought these coastal people might come from a lineage not closely related to those first agricultural East Asians. Maybe this group’s ancestry would be similar to the Tianyuan Man or Hòabìnhians.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="map showing different ancestral populations in Asia based on aDNA" src="https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/357988/original/file-20200914-18-160rygb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&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 with different lifestyles who lived far apart in northern China near the Yellow River and along the southern China coast as far back as 9,000 years ago both passed their distinct DNA down to present-day East Asians and Southeast Asians. Austronesians are the closest descendants of the ancient population from coastal southern China.</span>
<span class="attribution"><span class="source">Map © OpenStreetMap contributors, modified by The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>But instead, every person we sampled was closely related to present-day East Asians. That means that by 9,000 years ago, DNA common to all present-day East Asians was widespread across China.</p>
<p>Today’s northern and southern Chinese populations share more in common with ancient Yellow River populations than with ancient coastal southern Chinese. Thus, early Yellow River farmers migrated both north and south, contributing to the gene pool of humans across East and Southeast Asia. </p>
<p>The coastal southern Chinese ancestry did not vanish, though. It persisted in small amounts and did increase in <a href="https://doi.org/10.1038/s41467-020-16557-2">northern China’s Yellow River region over time</a>. The influence of ancient southern East Asians is low on the mainland, but they had a huge impact elsewhere. On islands spanning from the Taiwan Strait to Polynesia live the <a href="https://doi.org/10.1007/s00439-015-1620-z">Austronesians</a>, best known for their seafaring. They possess the <a href="https://doi.org/10.1126/science.aba0909">highest amount of southern East Asian ancestry today</a>, highlighting their ancestry’s roots in coastal southern China.</p>
<p><a href="https://doi.org/10.1101/2020.03.25.004606">Other emerging</a> <a href="https://doi.org/10.1126/science.aba0909">genetic patterns</a> show connections between Tibetans and ancient individuals from Mongolia and northern China, raising questions about the peopling of the Tibetan Plateau.</p>
<p>Ancient DNA reveals rapid shifts in ancestry over the last 10,000 years across Asia, likely due to migration and cultural exchange. Until more ancient human DNA is retrieved, scientists can only speculate as to exactly who, genetically speaking, lived in East Asia prior to that.</p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/139458/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Melinda A. Yang 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>
By studying the DNA of people who lived in East Asia thousands of years ago, scientists are starting to untangle how the region was populated.
Melinda A. Yang, Assistant Professor of Biology, University of Richmond
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/144570
2020-08-19T20:12:47Z
2020-08-19T20:12:47Z
Stone tools from a remote cave reveal how island-hopping humans made a living in the jungle millennia ago
<figure><img src="https://images.theconversation.com/files/353559/original/file-20200819-42823-req2bj.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3750%2C2890&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">ANU</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Prehistoric axes and beads found in caves on a remote Indonesian island suggest this was a crucial staging post for seafaring people who lived in this region as the last ice age was coming to an end.</p>
<p>Our discoveries, <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236719">published today in PLOS ONE</a>, suggest humans arrived on the tropical island of Obi at least 18,000 years ago, successfully making a living there for at least the next 10,000 years. </p>
<p>It also provides the first direct archaeological evidence to support the idea these islands were crucial for humans’ island-hopping migration through this region millennia ago.</p>
<p>In early April 2019, we and our colleagues in Indonesia became the first archaeologists to explore Obi, in Indonesia’s Maluku Utara province. </p>
<p>We found the oldest example from east Indonesia of edge-ground axes, made by grinding a piece of stone to a sharp blade against a rough material such as sandstone. These were likely used for clearing the forest and making dugout canoes. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Hand holding a prehistoric stone axe" src="https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353556/original/file-20200819-42831-1gqncd9.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">Stone axes were vital tools for clearing forest and making canoes.</span>
<span class="attribution"><span class="source">ANU</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our discoveries suggest the prehistoric people who lived on Obi were adept on both land and sea, hunting in the dense rainforest, foraging by the sea, and possibly even making canoes for voyaging between islands.</p>
<p>Our research is part of a <a href="https://epicaustralia.org.au/mapping-the-journeys-of-australias-first-people/">project</a> to learn more about how people first dispersed from mainland Asia, through the Indonesian archipelago and into Sahul, the prehistoric continent that once connected Australia and New Guinea. </p>
<h2>An island stepping-stone</h2>
<p>Recent <a href="https://epicaustralia.org.au/mapping-the-journeys-of-australias-first-people/">models</a> by <a href="https://www.nature.com/articles/s41598-019-42946-9">CABAH researchers</a> identified the collection of small islands in northeast Indonesia – and Obi in particular – as the most likely “stepping-stones” used by humans on their very first journey east towards northern Sahul (modern-day New Guinea), about 65,000-50,000 years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Obi and surrounding islands" src="https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=593&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=593&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=593&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=745&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=745&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353613/original/file-20200819-24815-zdtt7d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=745&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 the region showing the location of Obi island and the sites excavated by the team, and the previous geography of the region when sea levels were lower.</span>
</figcaption>
</figure>
<p>Migrating through this region, which is named <a href="https://theconversation.com/wallacea-a-living-laboratory-of-evolution-85602">Wallacea</a> after the explorer and naturalist Alfred Russel Wallace, would have required multiple sea crossings. This enormous archipelago thus has a unique significance in human history, as the region where people first set out on deliberate long sea voyages. </p>
<p>Our <a href="https://www.sciencedirect.com/science/article/pii/S0047248418302136">earlier research</a> suggested the northern Wallacean islands, including Obi, would have offered the easiest migration route. But to back this theory, we need archaeological evidence for humans living in this remote area in the ancient past. So we travelled to Obi to look for cave sites that might reveal evidence of early occupation.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/island-hopping-study-shows-the-most-likely-route-the-first-people-took-to-australia-93120">Island-hopping study shows the most likely route the first people took to Australia</a>
</strong>
</em>
</p>
<hr>
<h2>Tools and treasure</h2>
<p>We found two rock shelter sites, just inland from the village of Kelo on Obi’s northern coast, that were suitable for excavation. With the permission and help of the local people of Kelo, we dug a small test excavation in each shelter. </p>
<p>We found numberous artefacts including fragments of edge-ground axes, some dating to about 14,000 years ago. The earliest ground axes at Kelo were made using clam shells. Axes made from shells have also been found elsewhere in this region from roughly the same time, including on the nearby island of Gebe to the northeast. Traditionally, they were used by people in the region for the construction of dugout canoes. It is highly likely that Obi’s axes were also used for making canoes, thus allowing these early peoples to maintain connections between communities on neighbouring islands.</p>
<figure class="align-center ">
<img alt="People walking among coconut trees" src="https://images.theconversation.com/files/353561/original/file-20200819-24671-j439w8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353561/original/file-20200819-24671-j439w8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353561/original/file-20200819-24671-j439w8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353561/original/file-20200819-24671-j439w8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353561/original/file-20200819-24671-j439w8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353561/original/file-20200819-24671-j439w8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353561/original/file-20200819-24671-j439w8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The research team treks through coconut groves on Obi.</span>
<span class="attribution"><span class="source">ANU</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The oldest cultural layers from the Kelo 6 site, containing a combination of shell and stone tool flakes, provided us with the earliest record for human occupation on Obi, dating back around 18,000 years. At this time the climate was drier and colder the today, and the island’s dense rainforests would likely have been much less impenetrable than they are now. Sea levels were about 120 metres lower, meaning Obi was a much larger island, encompassing what is today the separate island of Bisa, as well as several other small islands nearby.</p>
<p>Roughly 11,700 years ago, as the most recent ice age ended, the climate became significantly warmer and wetter, no doubt making Obi’s jungle much thicker. It is perhaps no coincidence this is the time we see the first evidence of axes made from stone rather than sea shells, likely in response to their increased, heavy-duty use for clearing and modification of the increasingly dense rainforest. While stone takes about twice as long to grind into an axe compared to shell, the harder material also keeps its sharp edge for longer as well.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Various views of stone axes" src="https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=517&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=517&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=517&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=650&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=650&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353657/original/file-20200819-42893-t2s41e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=650&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Stone axes found on the ground near Kelo village. Scale bar represents 1cm.</span>
<span class="attribution"><span class="source">Shipton et al. 2020</span></span>
</figcaption>
</figure>
<p>Judging by the bones we found in the Kelo caves, people living there mainly hunted the <a href="https://www.iucnredlist.org/species/16852/6506978">Rothschild’s cuscus</a>, a possum-like animal that still lives on Obi today. As the forest grew more dense, people probably used axes to clear patches of forest and make hunting easier. </p>
<p>Again, it’s probably no coincidence axes made of volcanic stone – which would have stayed sharp for longer, and are known to have been used for this purpose in New Guinea – first appearing in the archaeological record at around the time the climate was changing. </p>
<p>We also found obsidian, which must have been brought over from another island as there is no known source on Obi, and particular types of shell beads in the Kelo caves, similar to those previously found on islands in southern Wallacea. This again supports the idea that Obi islanders routinely travelled to other islands.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Selection of ancient sea shell pieces" src="https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=427&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=427&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=427&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=537&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=537&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353557/original/file-20200819-24757-3totpy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=537&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sea shell fragments on the cave floor.</span>
<span class="attribution"><span class="source">ANU</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Moving out, or moving on?</h2>
<p>Our excavations suggest people successfully lived at the Kelo caves for about 10,000 years. But then, about 8,000 years ago, both sites were abandoned. </p>
<p>Did the residents leave Obi completely, or move elsewhere on the island? Perhaps the jungle had grown so thick human axes (even stone ones!) were no longer a match for the dense undergrowth. Perhaps people simply moved to the coast and became mainly fishers rather than hunters. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-incredible-journey-the-first-people-to-arrive-in-australia-came-in-large-numbers-and-on-purpose-114074">An incredible journey: the first people to arrive in Australia came in large numbers, and on purpose</a>
</strong>
</em>
</p>
<hr>
<p>Whatever the reason, we have no evidence for use of the Kelo shelters after this time, until about 1,000 years ago, when they were reoccupied by people who had pottery and metal items. It seems likely, in view of Obi’s location in the middle of the Maluku “Spice Islands”, this final phase of occupation saw the Kelo shelters used by people involved in the historic spice trade.</p>
<p>We will hopefully find the answers to some of these questions when we return to Obi next year, COVID permitting, to excavate some coastal caves.</p><img src="https://counter.theconversation.com/content/144570/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shimona Kealy receives funding from the Australian Research Council through the ARC Centre of Excellence for Australian Biodiversity and Heritage. She is affiliated with the Australian National University, College of Asia and the Pacific. </span></em></p><p class="fine-print"><em><span><a href="mailto:sue.oconnor@anu.edu.au">sue.oconnor@anu.edu.au</a> receives funding from the Australian Research Council
through the ARC Centre of Excellence for Australian Biodiversity and Heritage.
She is affiliated with the Australian National University, College of Asia and the Pacific.</span></em></p>
Archaeological discoveries in a jungle cave in central Indonesia suggest humans arrived there 18,000 years ago and decided to stay a while, hunting in the jungle and building canoes.
Shimona Kealy, Postdoctoral Researcher, College of Asia & the Pacific, Australian National University
Sue O'Connor, Distinguished Professor, School of Culture, History & Language, Australian National University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/142810
2020-07-22T19:51:24Z
2020-07-22T19:51:24Z
Humans inhabited North America in the depths of the last Ice Age, but didn’t thrive until the climate warmed
<figure><img src="https://images.theconversation.com/files/348770/original/file-20200722-29-1cgvogd.jpg?ixlib=rb-1.1.0&rect=2%2C8%2C1914%2C1267&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Chiquihuite Cave in Mexico.</span> <span class="attribution"><span class="source">Devlin A. Gandy</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Humans lived in what is now Mexico up to 33,000 years ago and may have settled the Americas by travelling along the Pacific coast, according to two studies by myself and colleagues published today. </p>
<p>It has been commonly believed that the first people to enter the Americas were big-game hunters from Asia, who arrived after the last Ice Age around 13,000 years ago. This narrative is known as the “Clovis first” theory, based on distinctive stone tools produced by a people archaeologists call the Clovis culture.</p>
<p>For most of the 20th century, this theory was widely accepted. However, more recent archaeological evidence has shown humans were present in the Americas before the Clovis people.</p>
<p>Just how much earlier, however, is unclear and a topic of intense academic debate. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ancient-dna-in-lake-mud-sheds-light-on-the-mystery-of-how-humans-first-reached-america-63776">Ancient DNA in lake mud sheds light on the mystery of how humans first reached America</a>
</strong>
</em>
</p>
<hr>
<h2>What we found in Chiquihuite Cave</h2>
<p>Chiquihuite Cave is an archaeological site more than 2,740 metres above sea level in Zacatecas, Mexico. Ciprian Ardelean of the University of Zacatecas has been leading excavations of the site for more than seven years. Nearly 2,000 stone tools and pieces created through their manufacture have been found. </p>
<p>The tools belongs to a type of material culture never before seen in the Americas, with no evident similarities to any other cultural complexes. Importantly, more than 200 specimens were found below an archaeological layer that corresponds to the peak of the last Ice Age. (Archaeologists call this peak the Last Glacial Maximum.) </p>
<p>During this time, between 26,000 and 19,000 years ago, ice sheets were at their greatest extent. Evidence from Chiquihuite Cave, therefore, strongly suggests that humans were present in North America well before Clovis. </p>
<figure class="align-center ">
<img alt="A hand holding a small stone tool." src="https://images.theconversation.com/files/348775/original/file-20200722-25-1m3rygt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/348775/original/file-20200722-25-1m3rygt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/348775/original/file-20200722-25-1m3rygt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/348775/original/file-20200722-25-1m3rygt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/348775/original/file-20200722-25-1m3rygt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/348775/original/file-20200722-25-1m3rygt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/348775/original/file-20200722-25-1m3rygt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A stone tool found below the Last Glacial Maximum layer.</span>
<span class="attribution"><span class="source">Ciprian Ardelean</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Given the significance of the discovery, myself and a team of international researchers joined in the interdisciplinary study of Chiquihuite Cave. Some of us had the opportunity to visit the site following a four-hour long journey by foot, and see the evidence at first hand. Our aims were to reconstruct the environment humans lived in and define exactly when they occupied the site. </p>
<p>My own research at Chiquihuite Cave focused on the latter. I helped to build a chronology of more than 50 radiocarbon and optical dates. </p>
<p>Combined with the archaeological evidence, the <a href="https://www.nature.com/articles/s41586-020-2509-0">results</a> showed humans inhabited Chiquihuite as early as 33,000 years ago, until the cave was sealed off at the end of the Pleistocene period (around 12,000 years ago). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman walking into a cave" src="https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/348240/original/file-20200719-29-52patm.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">Lorena Becerra-Valdivia inside Chiquihuite Cave in 2019, walking towards the archaeological excavations.</span>
<span class="attribution"><span class="source">Thomas L.C. Gibson</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The pattern of settlement</h2>
<p>In <a href="https://www.nature.com/articles/s41586-020-2491-6">a second paper</a>, I explore the wider pattern of human occupation across North America and Beringia (the ancient land bridge connecting America to Asia). This involved analysing hundreds of dates obtained from 42 archaeological sites in North America and Beringia, including Chiquihuite Cave, using a statistical tool called Bayesian age modelling. </p>
<p>The analysis showed there were humans in North America before, during and immediately after the peak of the last Ice Age. However, it was not until much later that populations expanded significantly across the continent. </p>
<p>This occurred during a period of climate warming at the end of the Ice Age called Greenland Interstadial 1. The warming began suddenly with a pulse of increased global temperature around 14,700 years ago. </p>
<p>We also observed that the three major stone tool traditions in the wider region started around the same time. This coincides with an increase in archaeological sites and radiocarbon dates from those sites, as well as genetic data pointing to marked population growth. </p>
<p>This significant expansion of humans during a warmer period seems to have played a role in the dramatic demise of large megafauna, including types of camels, horses and mammoths. We plotted the dates of the last appearance of the megafauna and found they largely disappeared within this, and a following, colder period. </p>
<p>However, the contribution of climate change in faunal extinctions, represented by abrupt warming and cooling, cannot be fully excluded. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-evidence-that-an-extraterrestrial-collision-12-800-years-ago-triggered-an-abrupt-climate-change-for-earth-118244">New evidence that an extraterrestrial collision 12,800 years ago triggered an abrupt climate change for Earth</a>
</strong>
</em>
</p>
<hr>
<p>The first human arrivals came from eastern Eurasia, yet it looks as though there was a surprisingly early movement of people into the continent. </p>
<p>We think the path of earlier arrivals to these new lands was probably along the coast. Inland travel would have been blocked, either because Beringia was partly underwater or because modern-day Canada was covered by impenetrable ice sheets.</p>
<p>Together, the two studies and their results depart from previously accepted models, and allow us to uncover a new story of the initial peopling of the Americas. This journey, marking one of the major expansions of modern humans across the planet, will continue to mystify and spark debate.</p><img src="https://counter.theconversation.com/content/142810/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lorena Becerra-Valdivia 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>
Stone tools found in a cave in Mexico have archaeologists rewriting the human history of the Americas.
Lorena Becerra-Valdivia, Postdoctoral Research Fellow, UNSW Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/132101
2020-02-25T19:00:26Z
2020-02-25T19:00:26Z
Stone tools show humans in India survived the cataclysmic Toba eruption 74,000 years ago
<figure><img src="https://images.theconversation.com/files/317004/original/file-20200225-24668-1t3hkj5.JPG?ixlib=rb-1.1.0&rect=3%2C6%2C2281%2C1702&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Christina Neudorf</span>, <span class="license">Author provided</span></span></figcaption></figure><p>About 74,000 years ago a volcanic eruption at what is now Lake Toba in Sumatra, Indonesia, created one of the most dramatic natural disasters of the past 2 million years. The plume of the eruption punched 30 kilometres or more into the sky, eventually blanketing much of India and parts of Africa in a <a href="https://pubs.geoscienceworld.org/gsa/geology/article-abstract/15/10/913/204210/Dispersal-of-ash-in-the-great-Toba-eruption-75-ka">layer of ash</a>.</p>
<p>Some scientists <a href="https://www.cambridge.org/core/journals/quaternary-research/article/climatevolcanism-feedback-and-the-toba-eruption-of-74000-years-ago/6C5611CF710962C41436E08196EFE9E6">argue</a> the eruption plunged Earth into a six-year “volcanic winter” followed by a thousand-year cooling of the planet’s surface. The long chill, the argument goes, may have resulted in the near extinction of our own species. </p>
<p>One <a href="https://www.sciencedirect.com/science/article/abs/pii/S0047248498902196">prominent theory</a> says the eruption was a key event in human evolution. If this is right, the few human survivors in Africa would have developed more sophisticated social, symbolic and economic strategies to cope with the harsh conditions. These new strategies might then have enabled them to repopulate Africa and migrate into Europe, Asia and Australia by 60-50,000 years ago. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/armageddon-and-its-aftermath-dating-the-toba-super-eruption-10393">Armageddon and its aftermath: dating the Toba super-eruption</a>
</strong>
</em>
</p>
<hr>
<p>It is still unclear how intense the fallout from the Toba eruption really was, and how it affected humans. The debate has been running for decades, drawing on evidence from climate science, geology, archaeology and genetics.</p>
<p>We have found new evidence that humans in India survived the Toba eruption and continued to flourish after it. The study – by researchers from the University of Queensland, the University of Wollongong, the Max Planck Institute for the Science of Human History, the University of Allahabad and others – is <a href="https://www.nature.com/articles/s41467-020-14668-4">published in Nature Communications</a> today.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=532&fit=crop&dpr=1 600w, https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=532&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=532&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=668&fit=crop&dpr=1 754w, https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=668&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/317006/original/file-20200225-24690-1of22zq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=668&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some of the stone tools found at Dhaba.</span>
<span class="attribution"><span class="source">Chris Clarkson</span></span>
</figcaption>
</figure>
<h2>Living through the eruption</h2>
<p>We studied a unique archaeological record that covers 80,000 years at the Dhaba site in the middle Son valley of northern India. Ash from the Toba eruption was found in the Son valley back in the 1980s, but until now there was no archaeological evidence to go with it. </p>
<p>The Dhaba site fills a major time gap in our understanding of how ancient humans survived and migrated out of Africa and across the world. The stone tools we found at Dhaba are similar to the ones people were using in Africa at the same time. </p>
<p>These toolkits were present at Dhaba before and after the Toba super-eruption, indicating that populations survived the event. It is likely that humans made the same kinds of tools all along the dispersal route from Africa through India, reaching Australia by <a href="https://www.nature.com/articles/doi:10.1038/nature22968">at least 65,000 years ago</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/buried-tools-and-pigments-tell-a-new-history-of-humans-in-australia-for-65-000-years-81021">Buried tools and pigments tell a new history of humans in Australia for 65,000 years</a>
</strong>
</em>
</p>
<hr>
<p>Dhaba therefore provides a crucial cultural link between Africa, Asia and Australia. Although fossil and genetic evidence indicate modern humans have lived outside Africa for the past 200,000 years (at sites such as Apedima, Misliya,
Qafzeh, Skhul, Al Wusta and Fuyan cave) only human fossil evidence can prove beyond doubt they were in India 80,000 years ago. </p>
<p>Nevertheless, the stone tools at Dhaba go a long way toward demonstrating human presence.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=371&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=371&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=371&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=467&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=467&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316996/original/file-20200225-24668-k6jcdh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=467&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Possible routes of ancient human migration.</span>
<span class="attribution"><span class="source">Chris Clarkson</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Putting together the puzzle</h2>
<p>Our findings at Dhaba fit with archaeological evidence from Africa, Asia, and elsewhere in India to support the idea that the Toba super-eruption had minimal effects on humans and did not cause a population bottleneck. Archaeological sites in southern Africa show human populations thrived following the Toba super-eruption. </p>
<p>Climate and vegetation records from Lake Malawi in East Africa likewise show <a href="https://www.pnas.org/content/early/2013/04/24/1301474110.abstract">no evidence</a> for a volcanic winter at the time of the eruption. Genetic studies similarly have not detected a clear population bottleneck around 74,000 years ago. </p>
<p>At Jwalapuram, in southern India, <a href="https://science.sciencemag.org/content/317/5834/114">Michael Petraglia and colleagues</a> found similar Middle Palaeolithic stone tools above and below a thick layer of Toba ash. At the Lida Ajer site in Sumatra, close to the eruption itself, Kira Westaway and colleagues <a href="https://www.nature.com/articles/nature23452">found human teeth</a> dated to 73,000-63,000 years ago. This indicates humans were living in Sumatra, in a closed-canopy rainforest environment not long after the eruption.</p>
<p>Our new findings contribute to a revised understanding of the global impact of the Toba super-eruption. While the Toba super-eruption was certainly a colossal event, global cooling may have been less significant than previously thought. </p>
<p>In any case, archaeological evidence suggests that humans survived and coped with one of the largest volcanic events in human history. Small bands of hunter-gatherers turned out to be highly adaptable in the face of climate change. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/under-the-volcano-predicting-eruptions-and-coping-with-ash-rain-32899">Under the volcano: predicting eruptions and coping with ash rain</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/132101/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Clarkson receives funding from the Australian Research Council</span></em></p><p class="fine-print"><em><span>Michael Petraglia 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>
An archaeological site in India sheds new light on how ancient humans dispersed from Africa across the world.
Chris Clarkson, Professor in Archaeology, The University of Queensland
Michael Petraglia, Professor of Archaeology, Max Planck Institute of Geoanthropology
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/117183
2019-08-15T02:13:07Z
2019-08-15T02:13:07Z
How ancient seafarers and their dogs helped a humble louse conquer the world
<figure><img src="https://images.theconversation.com/files/287955/original/file-20190814-136176-dom5tp.jpg?ixlib=rb-1.1.0&rect=0%2C2%2C995%2C606&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Male (left) and female Heterodoxus spiniger from Borneo.</span> <span class="attribution"><span class="source">Natural History Museum, London</span>, <span class="license">Author provided</span></span></figcaption></figure><p>This is the story of how a parasitic, skin-chewing insect came to conquer the world. </p>
<p>For more than a century, scientists have been puzzled as to how an obscure louse native to Australia came to be found on dogs across the world. <em>Heterodoxus spiniger</em> evolved to live in the fur of the agile wallaby. </p>
<p>Despite little evidence to back the idea, many researchers believed it was linked to <a href="https://www.tandfonline.com/doi/abs/10.2752/175303709X434149">people from Asia bringing the dingo to Australia</a> in ancient times. Perhaps people later took dingoes infested with this parasite back home, where it spread to local dogs, and onwards from there. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/dingoes-do-bark-why-most-dingo-facts-you-think-you-know-are-wrong-68816">Dingoes do bark: why most dingo facts you think you know are wrong</a>
</strong>
</em>
</p>
<hr>
<p>But when we approached the question again using the most up-to-date information, my colleague Peter Contos and I came up with a completely different explanation – one that better fits what we know of ancient migration and trade in the Asia-Pacific region.</p>
<p>As we report in the journal <a href="https://www.tandfonline.com/doi/full/10.1080/14614103.2019.1653619">Environmental Archaeology</a>, this louse probably originated not in Australia but in New Guinea, an island with a long history of intimate connection with seafaring Asian cultures.</p>
<h2>Louse on the loose</h2>
<p><em>H. spiniger</em> is a tiny louse that lives on mammals around the world, mostly dogs. Using its clawed legs to hang on, it bites and chews at the skin and hair of its hosts to draw the blood on which it feeds.</p>
<p>As all its closest relatives are <a href="https://www.sciencedirect.com/science/article/abs/pii/0020751994901953">specialised parasites of marsupials</a>, mostly other wallabies, logic suggested that <em>H. spiniger</em> must have evolved within Australia. It also seemed logical it would have spread first to the dingo, Australia’s native dog.</p>
<p>Our first task was to figure out just how far away from Australia it had spread; this would inform the likely pathways by which it could have travelled to the wider world. </p>
<p>We looked at museum collections, entomological surveys, and veterinary research reports to generate a map of its worldwide distribution.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=268&fit=crop&dpr=1 600w, https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=268&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=268&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=337&fit=crop&dpr=1 754w, https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=337&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/287951/original/file-20190814-136186-1ddmp4k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=337&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Global distribution of <em>H. spiniger</em>.</span>
<span class="attribution"><span class="source">Lougoulos and Contos</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The specimens we found, collected from the late 19th century to the present day, showed that this species is found on every continent except Europe and Antarctica.</p>
<p>But in Australia, we couldn’t find a single verifiable instance of the parasite living on dingoes. The only cases were from agile wallabies and domestic dogs.</p>
<p>That meant the prevailing wisdom had been wrong, and we had to look elsewhere for the origins of <em>H. spiniger</em>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/287954/original/file-20190814-136176-5rt7e5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/287954/original/file-20190814-136176-5rt7e5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=500&fit=crop&dpr=1 600w, https://images.theconversation.com/files/287954/original/file-20190814-136176-5rt7e5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=500&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/287954/original/file-20190814-136176-5rt7e5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=500&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/287954/original/file-20190814-136176-5rt7e5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=629&fit=crop&dpr=1 754w, https://images.theconversation.com/files/287954/original/file-20190814-136176-5rt7e5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=629&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/287954/original/file-20190814-136176-5rt7e5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=629&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t blame the dingoes.</span>
<span class="attribution"><span class="source">Blanka Berankova/Shutterstock</span></span>
</figcaption>
</figure>
<h2>Where did it really come from?</h2>
<p>Although marsupials are best known from Australia, they are also found in other parts of the surrounding region. The agile wallaby is <a href="https://www.iucnredlist.org/species/40560/21954106">also native to the island of New Guinea</a>, which was once joined with Australia.</p>
<p>Dogs have also been in New Guinea for <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.3487">at least as long</a> as the dingo has been in Australia. Traditionally, dogs were kept in Papuan villages, and were used to hunt game, including wallabies.</p>
<p>It came as little surprise, then, that we found <em>H. spiniger</em> on both agile wallabies and native dogs in New Guinea – and only a few decades after the first ever identification of the species.</p>
<p>So here was a more likely place in which the first transfer from wallaby to dog took place. But who took them out of New Guinea and into the wider world? </p>
<h2>Austronesian voyagers</h2>
<p>New Guinea was first colonised by humans around the same time as Australia. But since that time, compared with Australia it has had notably stronger connections with the outside world, reaching back millennia before European colonisation of Australia in 1788. </p>
<p>Around 4,000 years ago, agriculturalists known as Austronesians sailed out of Taiwan to settle several archipelagos in Oceania. With them they brought domestic species of plants and animals, including dogs.</p>
<p>By 3,000 years ago, at the latest, they <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0134497">reached New Guinea</a>. We suggest this was the crucial moment when dogs first picked up <em>H. spiniger</em>.</p>
<p>In the ensuing centuries, Austronesians went on to settle much of Indonesia, the Philippines, Melanesia and Polynesia, and coastal sections of mainland Southeast Asia. </p>
<p>They even settled as far as Madagascar, suggesting their voyages probably took them around the rim of the Indian Ocean, along the margins of India and the Middle East. </p>
<p>Dogs accompanying the migrants probably helped spread the louse, which is found almost everywhere they went. </p>
<p>This spans an enormous distance – from Hawaii to Madagascar – a testament to the ancient Austronesians’ supreme seafaring skills.</p>
<h2>New directions</h2>
<p>Our research suggests how the parasite first got around the world, but not precisely when. Its journey probably progressed at different times in different places.</p>
<p>The Austronesian diaspora established <a href="https://www.tandfonline.com/doi/abs/10.1080/03122417.2008.11681877">trade routes between the places they settled</a>, some of which spanned impressive distances across several island groups.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-get-to-australia-more-than-50-000-years-ago-96118">How to get to Australia ... more than 50,000 years ago</a>
</strong>
</em>
</p>
<hr>
<p>Later, foreign traders connected these communities with greater Asia and Africa. And in modern times, dogs continue to be transported as desirable goods themselves. </p>
<p>Trade and contact has probably led to further, possibly ongoing, dispersal of <em>H. spiniger</em>.</p>
<p>Unfortunately there are no archaeological examples that could demonstrate the louse’s early presence outside New Guinea, because this species prefers hot, humid environments.</p>
<p>A genetic approach is a better way forward. A start would be testing specimens from different parts of the world, to see when different regional populations – if they exist - branched off from one another.</p>
<p>This is particularly important in tracking its spread to the Americas, which likely occurred in recent centuries alongside European colonisation. </p>
<p>This research will help us further understand how migration, contact and trade unfolded in the prehistoric Asia-Pacific region, and how it affected the animal species – including the humblest of parasites – we see there today.</p>
<hr>
<p><em>This paper would not have been possible without the contributions of Peter Contos, the work of volunteers on the Natural History Museum’s Boopidae of Australasia digitisation project, and the contributions of the public to Wikipedia Creative Commons, for which we are grateful.</em></p><img src="https://counter.theconversation.com/content/117183/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Loukas Koungoulos receives support from an Australian Government Research Training Program scholarship, and funding from the Carlyle-Greenwell Research Fund (University of Sydney).</span></em></p>
Reconsidering an old ecological conundrum comes up with a new perspective on migration, contact and trade in the Australia and Asia-Pacific region.
Loukas Koungoulos, PhD Candidate, University of Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/106914
2018-11-19T16:11:44Z
2018-11-19T16:11:44Z
New dates for ancient stone tools in China point to local invention of complex technology
<figure><img src="https://images.theconversation.com/files/246063/original/file-20181117-194516-nzuo6m.jpg?ixlib=rb-1.1.0&rect=8%2C0%2C1857%2C1362&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Several of the newly identified stone tools – unearthed from a museum collection.</span> <span class="attribution"><span class="source">Hu Yue</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>You probably think of new technologies as electronics you can carry in a pocket or wear on a wrist. But some of the most profound technological innovations in human evolution have been made out of stone. For most of the time that humans have been on Earth, they’ve chipped stone into useful shapes to make tools for all kinds of work. </p>
<p><a href="https://doi.org/10.1038/s41586-018-0710-1">In a study just published in Nature</a>, we’ve dated a distinctive and complex method for making stone tools to a much earlier timeframe in China than had previously been accepted. Archaeologists had thought that artifacts of this kind had been carried into China by groups migrating from Europe and Africa. But our new discovery, dated to between 170,000 and 80,000 years ago, suggests that they could have been invented locally without input from elsewhere, or come from much earlier cultural transmission or human migration.</p>
<p>Several different species of humans lived on Earth at this time, including modern ones like us. But we haven’t found any human bones from this site, so don’t know which species of human made these tools. </p>
<p>These Chinese artifacts provide one more piece of evidence that changes the way we think about the origin and spread of new stone tool technologies. And intriguingly we made our discovery based on artifacts that had been excavated decades ago.</p>
<h2>New technology among old stones</h2>
<p>Archaeologists have identified <a href="https://en.wikipedia.org/wiki/Stone_tool">five modes</a> humans have used to make stone tools over the last 3 million years. Each mode is represented by a new stone tool type that is dramatically different from what came before. The appearance of each new mode is also marked by a big increase in the number of steps needed to make the new tool type. </p>
<p>One of these modes, Mode III, also called Levallois, is at the center of several big debates about human evolution. Levallois tools are the defining features of the archaeological period referred to as the Middle Paleolithic, or Africa’s Middle Stone Age. They are the result of a set of very specific steps of chipping a piece of stone to create similar-sized tools suitable to be shaped for a variety of purposes. These steps are remarkable because they are a <a href="https://doi.org/10.1006/jasc.2000.0594">much more efficient way</a> to produce lots of useful cutting tools, with minimal wasted stone, compared to earlier technologies. </p>
<p>One of these debates is whether Mode III tools were invented in one place and then spread out, or independently invented in several different locations. Since the world’s <a href="https://doi.org/10.1038/nature22336">oldest securely dated Levallois tools</a> have been found in north Africa from around 300,000 years ago, it’s possible they spread out from there, carried by groups of early humans migrating across Europe and into Asia. On the other hand, finds of similarly early <a href="https://doi.org/10.1126/science.1256484">Levallois tools in Armenia</a> <a href="https://doi.org/10.1038/nature25444">and India</a> support the idea of independent inventions of the technology outside of Africa. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=481&fit=crop&dpr=1 600w, https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=481&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=481&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=605&fit=crop&dpr=1 754w, https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=605&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/246064/original/file-20181117-194513-wnyzlu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=605&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Levallois tools were a leap forward in technology, a new, efficient way to create tools that could cut, scrape, chop and make other types of tools.</span>
<span class="attribution"><span class="source">Hu Yue</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Changing the chronology in China</h2>
<p>In China it has been hard to find evidence of Mode III tools until <a href="https://doi.org/10.1016/j.quaint.2012.07.020">relatively late in the Palaeolithic period</a>, approximately 30,000 to 40,000 years ago. That’s concurrent with when Mode IV (blade tools) appear there. Ancient people in China appeared to leap from Mode II (stone hand axes) to Mode III and IV at the same time. This suggests that Levallois tools appeared in China when modern humans migrated in and brought these new technologies with them around 30,000 to 40,000 years ago.</p>
<p>Our results support a different story for the origin of Levallois tools in China. At Guanyindong Cave in <a href="https://www.google.com/maps/place/Guiyang,+Guizhou,+China/@26.8485833,102.1052778,6z/data=!4m13!1m7!3m6!1s0x36bf67eaae6dd399:0xec9c1d7600abd55e!2sGuizhou,+China!3b1!8m2!3d26.8429645!4d107.2902839!3m4!1s0x36bf67c355ec1b37:0x173381c0d8316455!8m2!3d26.6474587!4d106.6305542">Guizhou Province</a> in south-central China, we found Mode III tools in layers dated to around 170,000 and around 80,000 years ago. This puts them well before Mode IV tools, and at around the same time that Levallois were the main tools used in Europe and Africa. </p>
<p>One major implication of our new early ages from Guanyindong Cave is that the appearance of Levallois tools in China is no longer tied to the arrival of modern humans and Mode IV tools 30,000 to 40,000 years ago. Instead, Levallois tools could have been invented locally in China – maybe by a different human species. Another possibility is that they were introduced by a much earlier migration, perhaps by the people whose <a href="https://doi.org/10.1038/nature.2015.18566">teeth have been found in a cave in Daoxian</a>, <a href="https://www.google.com/maps/place/Hunan,+China/@22.0022602,102.1170918,5.05z/data=!4m5!3m4!1s0x3420ba186987384d:0xcc21910be4ae2ce5!8m2!3d27.6252995!4d111.8568586">Hunan Province</a>, who lived between 80,000 and 120,000 years ago.</p>
<p><iframe id="K0382" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/K0382/2/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Going back to Guanyindong Cave</h2>
<p>Our discovery is a little unusual because we didn’t do any major new excavations. All of the stone tools we studied had been <a href="https://doi.org/10.4116/jaqua.28.243">excavated from Guanyindong Cave</a> in the 1960s and 1970s. Since that time Guanyindong has been famous as one of the most important Paleolithic sites in South China because of the relatively large number of stone tools found there.</p>
<p>Most are stored at the <a href="http://english.ivpp.cas.cn/">Institute of Vertebrate Paleontology and Paleoanthropology</a> in Beijing, and our team spent a lot of time carefully inspecting each tool to identify the traces that reveal how it was made. It was during this painstaking analysis of the museum specimens that we encountered a few dozen Levallois tools among the thousands of artifacts in the collection. </p>
<p>During the previous excavations at Guanyindong Cave, researchers had used <a href="https://en.wikipedia.org/wiki/Uranium%E2%80%93thorium_dating">uranium-series methods</a> to date fossils found in the sediments. This technique relies on the <a href="https://www.thoughtco.com/definition-of-isotopes-and-examples-604541">radioactive decay of tiny amounts of uranium</a> that collects in bone shortly after it is buried to come up with an age range for its burial. But it’s hard to precisely determine the true age of bone using this method. At Guanyindong these uranium-series ages span a wide range, from <a href="https://europepmc.org/abstract/cba/527068">50,000 to 240,000 years ago</a>. Also, the association between the dated fossil pieces and the stone artifacts was not recorded in detail. These problems meant that we couldn’t work out what layers the dated fossils came from, and if they were close to any of the Levallois stone tools.</p>
<p>Using only information available from the previous excavation, we couldn’t be sure of the exact age of the Levallois tools in the museum. The dates were important to nail down, because if they were older than 30-40,000 years, then they could be the earliest Levallois tools found in China.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=520&fit=crop&dpr=1 754w, https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=520&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/246062/original/file-20181117-194497-13f9kch.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=520&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bo Li and Hu Yue collecting sediment samples from the same layers the stone tools had been in, in order to redate them.</span>
<span class="attribution"><span class="source">Weiwen Huang</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>To uncover the true age of these Levallois tools, we made several trips to the cave to collect new samples for dating. It was challenging to find a suitable location to get the samples because the previous excavations didn’t leave much behind and much of the site was covered with thick vegetation.</p>
<p>We collected our new sediment samples from places where artifacts were still visible in the wall of the excavation, so we could be sure of a close connection between our samples and the stone tools. Essentially we were trying to collect new dirt from the spots where the museum artifacts had originally been excavated. The plan was then to test the samples with more advanced dating techniques than had originally been available.</p>
<h2>Analyzing new samples to date old artifacts</h2>
<p>Back in the lab, we analyzed the samples using single-grain <a href="https://www.thoughtco.com/luminescence-dating-cosmic-method-171538">optically stimulated luminescence</a> methods. This technique can identify how much time has passed since each individual grain was last exposed to the sun. Dating many individual grains in a sample is important because it can tell us if tree roots, animals or insects have mixed younger sediments down into older ones. After we identified and removed intrusive younger grains, we found that one layer of artifacts dated to about 80,000 years ago. We dated a lower layer to about 170,000 years ago. Our museum work had identified Levallois tools in both of these layers. </p>
<p>With the combination of careful inspection of the museum collection, new fieldwork to collect samples, and a new laboratory method of dating the site, we had uncovered a surprising and important result. These Levallois tools are much older than those from any other sites in East Asia. This suggests a more widespread geographic distribution of Levallois prior to the dispersal of modern humans out of Africa and Europe into Asia.</p>
<p>One reason why it has been so hard to find evidence of the technique in China until now is that the number of people in East Asia during the Palaeolithic might have been much smaller than in the West. Small, <a href="https://doi.org/10.1016/j.quaint.2008.12.001">low-density populations with weak and irregular patterns of social activity</a> might make it hard for new technologies to spread and persist over a long time.</p>
<p>We don’t know what species of human made the tools at Guanyindong because we haven’t found any bones. Whoever they were, they had similar skills to people living in the West at the same time. They appear to have independently discovered the Levallois strategy in China at the same time people were making extensive use of it in Europe and Africa.</p><img src="https://counter.theconversation.com/content/106914/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ben Marwick receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Bo Li receives funding from Australian Research Council.</span></em></p><p class="fine-print"><em><span>Hu Yue receives funding from the University of Wollongong.</span></em></p>
A fresh look at museum artifacts fills in a gap in the Asian archaeological record and refutes the idea that an advanced technique was imported from the West by early modern humans.
Ben Marwick, Associate Professor of Archaeology, University of Washington
Bo Li, Principal Research Fellow in Archaeological Science, University of Wollongong
Hu Yue, Postgraduate Student in Earth and Environmental Sciences, University of Wollongong
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/100752
2018-08-02T23:18:12Z
2018-08-02T23:18:12Z
We know why short-statured people of Flores became small – but for the extinct ‘Hobbit’ it’s not so clear
<figure><img src="https://images.theconversation.com/files/230340/original/file-20180802-136652-1p40tmn.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rampasasa people are from Waemulu village, Flores – near Liang Bua where 'the Hobbit' fossils were discovered. </span> <span class="attribution"><span class="source">Dean Falk, Florida State University </span>, <span class="license">Author provided</span></span></figcaption></figure><p>Humans are diverse in size and shape – but some populations are of relatively low average height, and historically described using the term “pygmy”. Some researchers have suggested that the Rampasasa inhabitants of the Flores highlands of Indonesia are one such group.</p>
<p>A paper published today in <a href="http://science.sciencemag.org/lookup/doi/10.1126/science.aar8486">Science</a> looked at whether the Rampasasa are related to an ancient human-like being that was also small in stature and once lived on the island of Flores – the archaic hominin <em>Homo floresiensis</em>, commonly referred to as “<a href="https://www.nature.com/news/the-discovery-of-homo-floresiensis-tales-of-the-hobbit-1.16197">the Hobbit</a>”. The Rampasasa live near Liang Bua, where the Hobbit fossils were first discovered. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-hobbit-took-our-breath-away-now-its-the-new-normal-60784">The Hobbit took our breath away: now it's the new normal</a>
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</em>
</p>
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<p>The study finds no evidence of a genetic relationship – which isn’t surprising, even though a <a href="http://www.pnas.org/content/103/36/13421.short">paper published in 2006</a> suggested otherwise.</p>
<p>The key claim made by today’s paper is that there have been two independent cases of insular dwarfism (reduction in size over time) evolving on Flores: one in our species <em>Home sapiens</em>, and another that resulted in the emergence of <em>Homo floresiensis</em>. </p>
<p>But is this really the case? </p>
<h2>Short-statured humans</h2>
<p>In anthropology, the term “pygmy” refers to populations with an average male stature of less than 150cm and an average female stature of less than 140cm – here we’ll use the term “short-statured”. </p>
<p>There are true short-statured populations to this day in the Andaman Islands (north of Sumatra) and the African rainforests, and borderline peoples in the rainforests of the Malay Peninsula and the Philippines. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/230330/original/file-20180802-118933-1szsx7x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/230330/original/file-20180802-118933-1szsx7x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/230330/original/file-20180802-118933-1szsx7x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/230330/original/file-20180802-118933-1szsx7x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/230330/original/file-20180802-118933-1szsx7x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/230330/original/file-20180802-118933-1szsx7x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/230330/original/file-20180802-118933-1szsx7x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Short-statured Baka men preparing to hunt with nets in the Dzanga-Sangha Forest Reserve, Central African Republic.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dzangasangha-forest-reserve-centralafrican-republic-car-451013683?src=3dp-gdzWMDkPbGRc_1MWWw-1-6">Sergey Uryadnikov / Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Across Africa, South Asia and South East Asia, short-statured populations in the past were interpreted as representing a single ancient migration out of Africa of modern humans who all shared a close ancestry.</p>
<p>Even in Australia, it was considered by one anthropologist (<a href="https://en.wikipedia.org/wiki/Joseph_Birdsell">Dr Joseph Birdsell</a>) that short-statured Indigenous people living in the closed rainforests behind Cairns were part of this first ancient migration of modern humans. </p>
<p>This hypothesis came <a href="https://www.jstor.org/stable/24046693?seq=1#page_scan_tab_contents">undone</a> through a better understanding of the <a href="https://www.nature.com/articles/nature18299">genetic diversity</a> of these populations and improved knowledge of how modern humans <a href="https://www.sciencedirect.com/science/article/pii/S0169534709000421">adapt</a> to closed forests – including in <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.20640">Australia</a>. </p>
<h2>The stature of the Rampasasa</h2>
<p>According to <a href="http://www.worldcat.org/title/anthropological-survey-of-the-eastern-little-sunda-islands-the-negritos-of-the-eastern-little-sunda-islands-the-proto-malay-of-the-netherlands-east-indies/oclc/609580">1940s data</a> collected by enigmatic anthropologist W. Keers, average male stature varied between 154cm and 163cm in the Indonesia’s Flores highlands, central Timor and Sumba. They are short people, yes, but not so-called “pygmies” by classical definition. </p>
<p>The same would apply to the Rampasasa, based on their <a href="http://www.pnas.org/content/103/36/13421.short">average stature of 146cm</a> across 35 males and 41 females. Given this is a mixed sex sample, it’s somewhat confusing that the new <a href="http://science.sciencemag.org/lookup/doi/10.1126/science.aar8486">Science paper</a> refers to the Rampasasa as “pygmies”. </p>
<p>Semantics aside, the tiny stature of 110cm for “the Hobbit” <em>Homo floresiensis</em> (female) type is well below the recorded range for modern humans, “pygmy” or otherwise. Various attempts have been made to attribute the tiny stature of “the Hobbit” to diseases such as <a href="http://www.pnas.org/content/103/36/13421.short">microcephaly</a>, <a href="https://www.sciencedirect.com/science/article/pii/S0018442X12001102">cretinism</a>, <a href="http://www.pnas.org/content/111/33/11967">Down sydrome</a> and <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.20655">Laron syndrome</a>. </p>
<p>However these attempts have been unsuccessful in explaining the unique suite of <em>Homo floresiensis</em> characteristics that clearly distinguish it from <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0155731">any modern humans</a>.</p>
<h2>The ‘Hobbit’ was tiny</h2>
<p>The existence of “the Hobbit” is based on an original fossil reported at <a href="https://www.nature.com/news/the-discovery-of-homo-floresiensis-tales-of-the-hobbit-1.16197">Liang Bua in 2004</a>, and possibly additional evidence located at the earlier site of Mate Menge <a href="https://www.nature.com/articles/nature17999">reported in 2016</a> </p>
<p>So how could <em>Homo floresiensis</em> have developed its unique features, of which tiny size is just one? </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/down-syndrome-theory-on-hobbit-species-doesnt-hold-to-scrutiny-33375">Down syndrome theory on Hobbit species doesn't hold to scrutiny</a>
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<p>According to archaeological evidence, their ancestors arrived on Flores approximately a million years ago, which allows ample time for evolution through isolation of a species (if we accept the Mate Menge fossil as also being <em>Homo floresiensis</em>) dated to 700,000–60,000 years ago. </p>
<p>Some palaeoanthropologists argue that the Hobbit direct ancestor was the Asian hominin <em><a href="https://australianmuseum.net.au/homo-erectus">Homo erectus</a></em>, commonly referred to as “Java Man” because it inhabited Java from about 1.7 million years ago until sometime before 100,000 years ago. </p>
<p><a href="https://en.wikipedia.org/wiki/Foster%27s_rule">Insular dwarfing</a> may explain the tiny size (and remarkably small braincase) of the Hobbit, but it does not easily explain the other features of the skull and lower skeleton that appear more primitive than recorded for <em>Homo erectus</em>. </p>
<p>A number of scientists employing <a href="https://evolution.berkeley.edu/evolibrary/article/phylogenetics_01">phylogenetic techniques</a> that are commonly used across palaeontology propose that a more ancient hominin, perhaps one more closely related to <em><a href="http://humanorigins.si.edu/evidence/human-fossils/species/homo-habilis">Homo habilis</a></em> must have reached Flores to give rise to the Hobbit. </p>
<p>Recent <a href="https://theconversation.com/humankinds-odyssey-from-africa-began-more-than-two-million-years-ago-99671">archaeological finds in China</a> dated to 2.1 million years ago support the idea that an older, pre-erectus hominin may have been present in Asia. </p>
<p>More fossil evidence is required before we can confidently classify the Hobbit, and establish if it is derived from <em>Homo erectus</em> or whether it represents a so-called “pre-erectus” hominin.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/humankinds-odyssey-from-africa-began-more-than-two-million-years-ago-99671">Humankind's odyssey from Africa began more than two million years ago</a>
</strong>
</em>
</p>
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<h2>Modern humans in Southeast Asia</h2>
<p>Modern humans first moved into the region of Island Southeast Asia as early as <a href="https://www.nature.com/articles/nature22968">65,000</a> years ago, heralding the seaborne colonisation of Australia and New Guinea. A later migration of modern humans from Northeast Asia occurred into Island Southeast Asia in the last <a href="http://press-files.anu.edu.au/downloads/press/p69411/mobile/ch05s02.html">4,000</a> years. </p>
<p>Different physical characteristics in peoples in this region may reflect these two migrations. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/worlds-scientists-turn-to-asia-and-australia-to-rewrite-human-history-88697">World's scientists turn to Asia and Australia to rewrite human history</a>
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<hr>
<p>The Science paper did find a small genetic contribution to the Rampasasa from two other archaic populations, but this does not distinguish them from other modern humans in the region. </p>
<p>One of these archaic populations is the Neanderthals, whose genetic signature is present in <a href="https://genographic.nationalgeographic.com/neanderthal/">all modern humans outside of Africa</a>. The other is the Denisovans, <a href="https://genographic.nationalgeographic.com/denisovan/">whose DNA</a> is known only from a finger bone found in a Siberian cave. </p>
<p>Denisovans have been identified as a minor contributor to the DNA of populations today in the Philippines, the islands near Flores, with slightly <a href="https://www.sciencedirect.com/science/article/pii/S0002929711003958">higher frequencies</a> in the DNA of people from New Guinea and Australia.</p>
<p>The genetic data obtained for the Rampasasa are entirely compatible with a dual ancestry as also found for other eastern Indonesians. </p>
<h2>A unique finding related to diet</h2>
<p>Perhaps the major contribution made by the <a href="http://science.sciencemag.org/lookup/doi/10.1126/science.aar8486">Science paper</a> is its analysis of a group of genes known as the fatty acid desaturatase (FADS) gene cluster, and how this could modulate dietary related selection pressures. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-origin-of-us-what-we-know-so-far-about-where-we-humans-come-from-54385">The origin of 'us': what we know so far about where we humans come from</a>
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<p>Where the diet is poor, the FADS gene cluster is shown to select for small stature. This mechanism could be of value in explaining the small stature of some populations (particularly in rainforests and on small islands), as well as other small-bodied individuals in some environments. </p>
<p>Indeed there may also be an insight here for understanding stature variation in archaic hominins like the Hobbit, if we are able to identify their genomes in ancient fossils or modern human sequences.</p><img src="https://counter.theconversation.com/content/100752/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Westaway receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>In 2006 Francis David Bulbeck received funding from the Australian Research Council to investigate whether microcephalic eastern Indonesian skulls could resemble Homo floresiensis.</span></em></p>
Modern day people of short stature became physically small due to the effects of living on a small island or forested environment. But we’re not sure why “the Hobbit” of Flores was so small.
Michael Westaway, Senior Research Fellow, Australian Research Centre for Human Evolution, Griffith University
Francis David Bulbeck, Senior Research Associate, Australian National University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/99671
2018-07-11T20:11:28Z
2018-07-11T20:11:28Z
Humankind’s odyssey from Africa began more than two million years ago
<figure><img src="https://images.theconversation.com/files/227066/original/file-20180711-27030-1v51nmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Looking for food, water and maybe adventure? </span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/N64wTMsjnXU">Unsplash </a></span></figcaption></figure><p>Can you imagine walking 14,000km? Trekking across wide savannas, down creek beds, along mountain chains in terrain that is new and home to foreign types of plants and animals? Can I eat this? What is that? </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/226920/original/file-20180710-70042-1y5fba6.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">One of the 2 million-year-old stone tools discovered at Shangchen, China.</span>
<span class="attribution"><span class="source">Photograph courtesy of R. Dennell.</span></span>
</figcaption>
</figure>
<p>This long excursion – once thought only to have been attempted late in the journey of humankind – has been getting pushed further and further back in time thanks to advancing archaeological research. </p>
<p><a href="https://www.nature.com/articles/s41586-018-0299-4">Findings published in Nature</a> today have extended the start of our worldwide trekking back to beyond 2.1 million years ago. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/worlds-scientists-turn-to-asia-and-australia-to-rewrite-human-history-88697">World's scientists turn to Asia and Australia to rewrite human history</a>
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<p>Previously, we knew that people were wandering around eastern Europe by 1.85 million years ago, as their bones and tools were discovered at a cave site called <a href="http://www.dmanisi.ge/page?id=2&lang=en">Dmanisi</a> in Georgia. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/227069/original/file-20180711-27015-p539r2.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ancient sites of global hominin presence.</span>
<span class="attribution"><a class="source" href="https://www.nature.com/articles/s41586-018-0299-4">John Kappelman/Nature (no reuse)</a></span>
</figcaption>
</figure>
<p>Presented in the <a href="https://www.nature.com/articles/s41586-018-0299-4">new paper</a> today, evidence for this earlier – and further – human movement comes in the form of flaked stone tools found in sediments at Shangchen, in the southern Chinese Loess Plateau. </p>
<p>Some 96 tools were found <em>in situ</em> – that is, still in the ground and undisturbed – and have shapes and traces of working recognisable to the archaeologist as distinctly human-made. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/SrvPOkMs4U4?wmode=transparent&start=83" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How are stone tools made? An expert explains.</span></figcaption>
</figure>
<h2>Out of Africa? Or Asia?</h2>
<p>Who were these early explorers? All signs point to hominids of the genus <em>Homo</em> (simply meaning “man”) – early people, <a href="http://humanorigins.si.edu/evidence/human-family-tree">some of whom led to our modern selves</a>. </p>
<p>An onslaught of recent findings from Asia has prompted some researchers to suggest that humans came “<a href="https://www.newscientist.com/article/mg23931850-200-asias-mysterious-role-in-the-early-origins-of-humanity/">Out of Asia</a>”. However, while it appears that people were in this region very early, humanity remains an African invention. </p>
<p>Our earliest ancestors arose in Africa some 6 million years ago, although the earliest remains of those belonging to our branch of the family tree – that of <em>Homo</em> – only date back to 2.8 million years ago. A single jawbone found in Ethiopia pushed back the <a href="https://www.smithsonianmag.com/science-nature/oldest-human-fossil-unearthed-ethiopia-180954470/">origins of our genus some 400,000 years</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/age-of-jawbones-mean-the-origins-of-humans-just-got-older-38722">Age of jawbones mean the origins of humans just got older</a>
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</p>
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<p>Currently, it seems that the earliest communities of <em>Homo</em> lived in eastern Africa for several hundred thousand years before heading out and away from the motherland. </p>
<h2>Human = adaptable = global conquest</h2>
<p>The apparent ease with which humankind has moved across vast landscapes continues to surprise scientists. Many of us now struggle with a hike that our ancestors would consider a relaxing stroll down the road. So how far did they walk at any one time? </p>
<p>Realistically, we have no way of answering this question for sure. Modern hunter-gatherers such as the Hadza regularly travel some ten (or more) kilometres each day in the course of their daily activities. Applying this rate of movement, someone could theoretically reach the new Chinese site of Shangchen from Africa in about four years. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/227082/original/file-20180711-27042-o0eyt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/227082/original/file-20180711-27042-o0eyt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/227082/original/file-20180711-27042-o0eyt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/227082/original/file-20180711-27042-o0eyt6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/227082/original/file-20180711-27042-o0eyt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/227082/original/file-20180711-27042-o0eyt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/227082/original/file-20180711-27042-o0eyt6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Hadza hunter with bow-and-arrow in Tanzania, 2013.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/lake-eyasi-tanzania-february-18-unidentified-134540183?src=3iHm0pYi_FRzRzIPC1b9Ew-1-19">from www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>In reality, the journey from Africa to Asia (and beyond) wasn’t one great trek undertaken by particularly adventurous individuals searching for… treasure? fame? glory? Instead, it is likely that small groups moved only a little at a time as their families expanded, or necessary resources ran dry. </p>
<p>One can imagine the family matriarch and/or patriach saying to their extended family, something along the lines of, “Let us go to the next valley (or the next river) where there are plenty of fish/deer and it isn’t so crowded.”</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/rhino-fossil-rewrites-the-earliest-human-history-of-the-philippines-95879">Rhino fossil rewrites the earliest human history of the Philippines</a>
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</em>
</p>
<hr>
<p>Perhaps on occasion there were a few irrepressible people who wanted to explore new lands and did cover significant distances in a single spurt. Perhaps they set up a new home far from their ancestors. </p>
<p>Certainly, such things have happened in recent times – Western Europeans turning up in Australia or North America, for example. </p>
<p>For the first humans moving out of Africa, there would not have been anyone to parlay with on arrival to new territories. Instead, they would have been entirely on their own when learning how to avoid new and exotic dangerous animals, identify and locate new foods and toolmaking supplies, and develop new ways to navigate. Each new landscape would have presented a significant challenge. Successfully setting up home or simply passing through without serious incident was no small feat. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/chickens-tell-tale-of-human-migration-across-pacific-24461">Chickens tell tale of human migration across Pacific</a>
</strong>
</em>
</p>
<hr>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/YrOlE3x5JRs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Home on the Ocean. Colonisation of the Pacific and the last great human migration.</span></figcaption>
</figure>
<p>Humans are extremely flexible and adaptable to new environments. This trait has allowed a species that evolved in a hot grassy savanna to make its home in tropical rainforests, or the Arctic, or even on the ocean – as the <a href="http://www.abc.net.au/news/science/2016-10-04/dna-reveals-lapita-ancestors-of-pacific-islanders-came-from-asia/7893100">Lapita</a> people who colonised the Pacific did. </p>
<p>Ultimately, it allowed us to discover and colonise the entire globe as part of a multi-millenial human odyssey.</p><img src="https://counter.theconversation.com/content/99671/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michelle Langley is an Australian Research Council DECRA Research Fellow at the Australian Research Centre for Human Evolution at Griffith University.</span></em></p>
Conquer the globe? You bet we did – but when did it start? A new paper shows early humans made tools in China two million years ago.
Michelle Langley, ARC DECRA Research Fellow, Griffith University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/94670
2018-04-09T15:02:38Z
2018-04-09T15:02:38Z
Our fossil finger discovery points to earlier human migration in Arabia
<figure><img src="https://images.theconversation.com/files/213847/original/file-20180409-114109-rhsrf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">: Ian Cartwright/Michael Petraglia/Palaeodeserts Project</span></span></figcaption></figure><p>The Arabian Peninsula is a vast landmass at the crossroads of Africa and Eurasia. Yet until the last decade almost nothing was known about early humans in the area. In the last few years the team I work with have made <a href="http://www.palaeodeserts.com">many remarkable discoveries</a> in Saudi Arabia, but one thing was always missing: fossils of ancient humans.</p>
<p>This changed when we discovered a small bone with big implications in Saudi Arabia’s Nefud Desert two years ago. As my colleagues and I explain <a href="https://www.nature.com/articles/doi:10.1038/s41559-018-0518-2">in a new paper</a> in Nature Ecology and Evolution, this 90,000-year-old <a href="https://theconversation.com/uk/topics/homo-sapiens-2772"><em>Homo sapiens</em></a> finger bone fossil shows <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/evan.21455">human migration</a> into Eurasia occurred earlier than previously thought. And it also highlights the role of climate change in our early expansions. </p>
<p>For the past several years I have been conducting research in Saudi Arabia, as a co-investigator and field director of the international <a href="http://www.palaeodeserts.com">Palaeodeserts Project</a>. In 2014, we discovered the site of Al Wusta, close to another established archaeological site in the north-west of the country, and began serious research there in 2016.</p>
<p>We very soon found hundreds of animal fossils and human-made stone tools. Then we found a small fossil, one of the best preserved from the site. It had the characteristic shape of a part of a human finger bone, but could it really be that after so many years of looking, we had finally found an ancient human fossil?</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/213824/original/file-20180409-114128-1j2pplf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/213824/original/file-20180409-114128-1j2pplf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=384&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213824/original/file-20180409-114128-1j2pplf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=384&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213824/original/file-20180409-114128-1j2pplf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=384&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213824/original/file-20180409-114128-1j2pplf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=483&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213824/original/file-20180409-114128-1j2pplf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=483&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213824/original/file-20180409-114128-1j2pplf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=483&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Where the finger was found.</span>
<span class="attribution"><span class="source">Julien Louys/Michael Petraglia/Palaeodeserts Project</span></span>
</figcaption>
</figure>
<p>We used a technique called <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1002/evan.1360010207">uranium series dating</a> to determine that the finger bone was 90,000-years-old. This involved measuring how much of the tiny amount of uranium naturally found in the fossil had decayed into radioactive thorium and working out how long this must have taken.</p>
<p>The next challenge was identifying the species to which the fossil belonged. Was it a human or was it a Neanderthal, the only other hominin known in south-west Asia in this time period? It turns out that the finger bone belonged to our own species, <em>Homo sapiens</em>.</p>
<p>The part of the finger bone we had found, the middle section or “intermediate phalanx”, is very different in humans and Neanderthals. In basic terms, ours are longer and thinner while Neanderthals’ are <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.21428">shorter and squatter</a>. We also CT-scanned the Al Wusta fossil to produce a 3D computer model. We then used a technique called geometric morphometrics to compare the fine details of the fossil’s shape with the same part from many humans, extinct hominins and non-human primates to confirm it really was from an ancient human. </p>
<h2>New history</h2>
<p>This finger wasn’t just an interesting find in its own right. It could also help change our understanding of when humanity first spread out from its earliest homes. According to the old <a href="http://science.sciencemag.org/content/313/5788/796">textbook view</a>, our species evolved in Africa about 200,000 years ago. Despite a brief, failed expansion to the edge of Eurasia about 100,000 years ago when humans first tried migrating to the lands at the eastern end of the Mediterranean (the Levant), we only successfully spread out of Africa around 60,000 to 50,000 years ago.</p>
<p>Recent evidence suggests that much of this narrative is wrong. Findings in Africa, such as from the site of <a href="https://www.nature.com/articles/nature22336">Jebel Irhoud</a> in Morocco, suggest that <em>Homo sapiens</em> appeared early, more than 300,000 years ago. Our origin does not seem to have occurred in only one small area, but across much of Africa.</p>
<p>Findings from the Levant, most recently the dating of a maxilla (upper jawbone) from <a href="http://science.sciencemag.org/content/359/6374/456">Misliya Cave</a> in Israel, suggest our species repeatedly expanded into the winter-rainfall fed, forested area just outside Africa. We don’t yet know if people survived long term in the Levant, which is a very small area. It seems more likely that there were repeated migrations from Africa.</p>
<p>But what about the areas beyond the Levant? Recent findings suggest that our species got to <a href="https://www.nature.com/articles/nature15696">East Asia</a> and <a href="https://www.nature.com/articles/nature22968">Australia</a> much earlier than had been thought. But determining the hominin species present and the age of these sites have proven challenging.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/213826/original/file-20180409-114080-1jd46p4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/213826/original/file-20180409-114080-1jd46p4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213826/original/file-20180409-114080-1jd46p4.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213826/original/file-20180409-114080-1jd46p4.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213826/original/file-20180409-114080-1jd46p4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213826/original/file-20180409-114080-1jd46p4.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213826/original/file-20180409-114080-1jd46p4.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hundreds of tools and animal bones were found but only one human fossil.</span>
<span class="attribution"><span class="source">Klint Janulis/Michael Petraglia/Palaeodeserts Project</span></span>
</figcaption>
</figure>
<p>Our finger fossil gives us a more specific time range to work with, which correlates with other evidence. Stone tools from Al Wusta are <a href="http://www.palaeodeserts.com/wp-content/uploads/2012/11/Groucutt-et-al.pdf">similar</a> to those from the Middle Palaeolithic (Stone Age) period in the Levant and north-east Africa. They suggest that our early spread into Eurasia was not associated with some kind of technological breakthrough, such as the invention of projectile technology as <a href="https://pdfs.semanticscholar.org/35e4/b8725a3dec7fefa9c378c0d1185ded6b6402.pdf">some have suggested</a>.</p>
<p>Together, these findings show that <em>Homo sapiens</em> had spread beyond the Levant much earlier than traditional accounts would have it. The Al Wusta phalanx is the oldest directly dated fossil of our species beyond Africa and the Levant and so represents a crucial reference point in understanding this topic.</p>
<p>The challenge for the future is working out what became of the population to which the Al Wusta human belonged. The Al Wusta human lived in a very different landscape from the current desert in which it was found. The kinds of animal fossils and features of the sediments show that the site was once a freshwater lake in a grassland environment.</p>
<p>How did these ancient humans respond to the dramatic environmental change which dried out lakes such as that at Al Wusta? How did they relate to other populations? A single discipline alone – be it archaeology, genetics or palaeontology – can’t robustly explain the evolution and spread of our species. But by working together, I am confident that we can make major inroads into understanding our origins over the coming years.</p><img src="https://counter.theconversation.com/content/94670/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Huw Groucutt receives funding from the British Academy.</span></em></p>
How we found the oldest human fossil ever discovered outside Africa and the Levant.
Huw Groucutt, British Academy Postdoctoral Fellow, University of Oxford
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/91891
2018-03-02T11:42:41Z
2018-03-02T11:42:41Z
How people talk now holds clues about human migration centuries ago
<figure><img src="https://images.theconversation.com/files/208303/original/file-20180228-36680-1gzt1zc.jpg?ixlib=rb-1.1.0&rect=349%2C349%2C4132%2C2645&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What can a modern-day Creole language tell us about its first speakers in the 1600s?</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Paramaribo,_Suriname_(11987836025).jpg">M M</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Often, you can tell where someone grew up by the way they speak.</p>
<p>For example, if someone in the United States doesn’t pronounce the final “r” at the end of “car,” you might think they are from the Boston area, based on sometimes exaggerated stereotypes about American accents and dialects, such as “Pahk the cahr in Hahvahd Yahd.”</p>
<p>Linguists go deeper than the stereotypes, though. They’ve used <a href="http://www.tekstlab.uio.no/cambridge_survey/">large-scale surveys</a> to <a href="https://www.nytimes.com/interactive/2014/upshot/dialect-quiz-map.html">map out many features of dialects</a>. The more you know about how a person pronounces certain words, the more likely you’ll be able to pinpoint where they are from. For instance, linguists know that dropping the “r” sounds at the end of words is actually common in many English dialects; they can map in space and time how r-dropping is widespread in the London area and has become increasingly common in England over the years. </p>
<p><a href="https://doi.org/10.1098/rstb.2017.0055">In a recent study</a>, we applied this concept to a different question: the formation of Creole languages. <a href="https://mona-uwi.academia.edu/ASherriah">As a linguist</a> and a <a href="https://scholar.google.com/citations?user=vwQdgAYAAAAJ&hl=en">biologist who studies cultural evolution</a>, we wanted to see how much information we could glean from a snapshot of how a language exists at one moment in time. Working with linguist <a href="https://www.mona.uwi.edu/dllp/jlu/staff/devonish.htm">Hubert Devonish</a> and psychologist <a href="https://profiles.stanford.edu/ewart-thomas">Ewart Thomas</a>, could we figure out the language “ingredients” that went into a Creole language, and where these “ingredients” originally came from?</p>
<h2>Mixing languages to make a Creole</h2>
<p>When a <a href="https://benjamins.com/#catalog/books/cll.25/main">Creole language forms</a>, it’s generally because <a href="http://www.ello.uos.de/field.php/Sociolinguistics/Theoriesofgenesis">two or more populations come together</a> without a common language to speak. Across history, this was often in the context of colonialism, indentured servitude and slavery. For example, in the U.S., <a href="http://www.afropedea.org/louisiana-creoles-people">Louisiana Creole</a> was formed by speakers of French and several African languages in the French slave colony of Louisiana. <a href="https://doi.org/10.1163/000000008792525228">As people mix</a>, a new language forms, and often the origins of individual words can be traced back to one of the source languages.</p>
<p>Our idea was that, if specific dialects were common among the migrants, the way they pronounce words might influence the pronunciations in the new Creole language. In other words, if English-derived words in a Creole exhibit r-dropping, we might hypothesize that the English speakers present when the Creole formed also dropped their r’s.</p>
<p><iframe id="tc-infographic-244" class="tc-infographic" height="400px" src="https://cdn.theconversation.com/infographics/244/d0929212fe8463b2bd63c88f0474e341fd78aee8/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Following this logic, we examined the pronunciation of Sranan, an English-based Creole still spoken in Suriname. We wanted to see if we could use language clues to identify where in England the original settlers came from. Sranan developed around the mid-17th century, due to contact between speakers of English dialects from England, migrants from elsewhere in Europe (such as Portugal and the Netherlands) and enslaved Africans who spoke a variety of West African languages.</p>
<p>As is the case with most English-based Creoles, the majority of the lexicon is English. Unlike most English Creoles, though, Sranan represents a linguistic fossil of the early colonial English that went into its development. In 1667, soon after Sranan was formed, the English ceded Suriname to the Dutch, and most English speakers moved elsewhere. So the indentured servants and other migrants from England had a brief but strong influence on Sranan.</p>
<h2>Using historical records to check our work</h2>
<p>We asked whether we could use features of Sranan to hypothesize where the English settlers originated and then corroborate these hypotheses via historical records.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=703&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=703&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=703&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=883&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=883&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208295/original/file-20180228-36700-182it7d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=883&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The similarity of each English dialect to Sranan. The most similar dialect, Blagdon, is indicated by a red arrow.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1098/rstb.2017.0055">source</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>First, we compared a set of linguistic features of modern-day Sranan with those of English as spoken in 313 localities across England. We focused on things like the production of “r” sounds after vowels and “h” sounds at the start of words. Since some aspects of English dialects have changed over the last few centuries, we also consulted historical accounts of both English and Sranan.</p>
<p>It turned out that 80 percent of the English features in Sranan could be traced back to regional dialectal features from two distinct locations within England: a cluster of locations near the port of Bristol and a cluster near Essex, in eastern England. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=822&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=822&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=822&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1033&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1033&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208294/original/file-20180228-36696-1505m3l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1033&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Circles represent the origin locations listed in ship records. The area of the circle is proportional to the number of individuals from that location. Bristol is marked by a yellow star, London by a blue star.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1098/rstb.2017.0055">source</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Then, we examined archival records such as the <a href="http://www.virtualjamestown.org/indentures/search_indentures.html">Bristol Register of Servants to Foreign Plantations</a> to see if the language clues we’d identified were backed up by historical evidence of migration. Indeed, these boat records indicate that indentured servants departing for English colonies were predominantly from the regions identified by our language analysis.</p>
<p><a href="https://doi.org/10.1098/rstb.2017.0055">Our research was proof of concept</a> that we could use modern information to learn more about the linguistic features that went into the formation of a Creole language. We can gain confidence in our conclusions because the historical record backed them up. Language can be a solid clue about the origins and history of human migrations. </p>
<p>We hope to use a similar approach to examine the African languages that have influenced Creole languages, since much less is known about the origins of enslaved people than the European indentured servants. Analyses like these might help us retrace aspects of forced migrations via the slave trade and paint a more complete linguistic picture of Creole formations.</p><img src="https://counter.theconversation.com/content/91891/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicole Creanza has received funding from the Ruth Landes Memorial Research Fund, the John Templeton Foundation, and the Stanford Center for Computational, Evolutionary, and Human Genomics. </span></em></p><p class="fine-print"><em><span>André Ché Sherriah 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>
New research suggests that hints left in Creole languages can identify where the original speakers came from – even hundreds of years after they migrated and mixed together.
Nicole Creanza, Assistant Professor of Biological Sciences, Vanderbilt University
André Ché Sherriah, Postdoctoral Associate in Linguistics, University of the West Indies, Mona Campus
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/89703
2018-01-10T10:19:00Z
2018-01-10T10:19:00Z
Ancient DNA sheds light on the mysterious origins of the first Scandinavians
<figure><img src="https://images.theconversation.com/files/200941/original/file-20180105-26157-1rs4xib.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"> Skeletal fragments from Hummervikholmen, one of sites featured in this study.
</span> <span class="attribution"><span class="source">Beate Kjørslevik</span></span></figcaption></figure><p>Tracking the migration of humans <a href="https://theconversation.com/heres-how-genetics-helped-crack-the-history-of-human-migration-52918">isn’t easy</a>, but genetics is helping us uncover new information at breathtaking speed. We know that our species originated in Africa and likely reached Europe from the southeast no later than 42,000 years ago. During the last ice age some 33,000-20,000 years ago, when a permanent ice sheet covered northern and parts of central Europe, modern humans in southwest Europe were isolated from groups further to the east. </p>
<p>When the ice sheet retreated, some of these hunter gatherers eventually colonised Scandinavia from the south about 11,700 years ago, making it one of the last areas of Europe to be inhabited. But exactly who these individuals were and how they got there has remained a puzzle for researchers. Now we have sequenced the genomes of seven hunter gatherers, dated to be 9,500-6,000 years old, to find out.</p>
<p>One of the reasons the origins of the first Scandinavians is so enigmatic is a major shift in stone tool technology that appeared soon after they got there. This new technology seemed to have had an origin in eastern Europe and <a href="http://dx.doi.org/10.1016/j.quaint.2014.02.023">it has been an open question</a> how it reached Scandinavia.</p>
<h2>Early migration</h2>
<p>Our interdisciplinary research team combined genetic and archaeological data with reconstructions of the ice sheets to investigate the earliest people of the Scandinavian peninsula. We extracted DNA for sequencing from bones and teeth of the seven individuals from the Norwegian Atlantic coast and the Baltic islands of Gotland and Stora Karlsö. </p>
<p>We then compared the genomic data with the genetic variation of contemporary hunter gatherers from other parts of Europe. To our surprise, hunter gatherers from the Norwegian Atlantic coast were genetically more similar to contemporaneous populations from east of the Baltic Sea, while hunter gatherers from what is Sweden today were genetically more similar to those from central and western Europe. One could say that – in Scandinavia at that time – the geographic west was the genetic east and vice versa. </p>
<p>This contradiction between genetics and geography can only be explained by two main migrations into Scandinavia. It would have started with an initial pulse from the south – modern day Denmark and Germany – that took place just after 11,700 years ago. Then there would have been an additional migration from the northeast, following the Atlantic coast in northern Finland and Norway becoming free of ice.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/201036/original/file-20180106-26151-14ho100.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/201036/original/file-20180106-26151-14ho100.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/201036/original/file-20180106-26151-14ho100.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/201036/original/file-20180106-26151-14ho100.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/201036/original/file-20180106-26151-14ho100.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/201036/original/file-20180106-26151-14ho100.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/201036/original/file-20180106-26151-14ho100.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artist’s impression of the last ice age.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Last_glacial_period#/media/File:IceAgeEarth.jpg">wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>These results, <a href="http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2003703">published in the PLOS Biology</a>, agree with archaeological observations that the earliest occurrences of the new stone tool technology in Scandinavia were recorded in Finland, northwest Russia and Norway – dating to about 10,300 years ago. This kind of technology only appeared in southern Sweden and Denmark later on.</p>
<h2>Blue eyes, blonde hair</h2>
<p>Knowing the genomes of these hunter gatherer groups also allowed us to look deeper into the population dynamics in stone age Scandinavia. One consequence of the two groups mixing was a surprisingly large number of genetic variants in Scandinavian hunter gatherers. These groups were genetically more diverse than the groups that lived in central, western and southern Europe at the same time. That is in stark contrast to the pattern we see today where more genetic variation is found in southern Europe and less in the north.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/201325/original/file-20180109-36016-1igvk0b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/201325/original/file-20180109-36016-1igvk0b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=456&fit=crop&dpr=1 600w, https://images.theconversation.com/files/201325/original/file-20180109-36016-1igvk0b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=456&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/201325/original/file-20180109-36016-1igvk0b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=456&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/201325/original/file-20180109-36016-1igvk0b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=573&fit=crop&dpr=1 754w, https://images.theconversation.com/files/201325/original/file-20180109-36016-1igvk0b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=573&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/201325/original/file-20180109-36016-1igvk0b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=573&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Axe, fish hook and other stone tools from the earliest Scandinavians, found in a cave on Gotland.</span>
<span class="attribution"><span class="source">Jan Apel</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The two groups that came to Scandinavia were originally genetically quite different, and displayed distinct physical appearances. The people from the south had blue eyes and relatively dark skin. The people from the northeast, on the other hand, had a variation of eye colours and pale skin.</p>
<p>Originally, humans are a species from warmer climates closer to the equator and we mainly cope with challenging environments with specific behaviour and technology. This includes making fires, clothes and specialised hunting equipment. However, in the long term there is also potential for adaptation through genetic changes. </p>
<p>For example, we found that genetic variants associated with light skin and eye pigmentation were carried, on average, in greater frequency among Scandinavian hunter gatherers than their ancestors from other parts of Europe. Scientists believe that light skin pigmentation <a href="https://www.livescience.com/7863-people-white.html">helps people better absorb sunlight</a> and synthesise vitamin D from it. </p>
<p>That suggests that local adaptation to the high-latitude climate associated with low levels of sunlight and low temperatures took place in Scandinavia after these groups arrived. In fact, this is in agreement with the worldwide pattern of pigmentation <a href="https://www.ncbi.nlm.nih.gov/books/NBK210015/">decreasing with distance to the equator</a>.</p>
<p>Modern people of northern Europe trace relatively little genetic ancestry back to the early Scandinavians studied by us. That’s because several later migrations have changed the Scandinavian gene pool over time. We know that migrations during the later stone age, the bronze age and historical times have brought new genetic material as well as novel technologies, cultures and languages. </p>
<p>The picture is similarly complex in other parts of the world. Hopefully it won’t be long before genetics helps us work out the detailed picture of exactly how humans have spread across the world since we first emerged.</p><img src="https://counter.theconversation.com/content/89703/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jan Apel receives funding from Swedish Research Council, Berit Wallenberg Foundation and Palmska fonden</span></em></p>
Scandinavia was populated by two main migrations, making its first inhabitants more genetically diverse and adapted to harsh climates than those in the rest of Europe.
Jan Apel, Senior Lecturer of Archaeology, Lund University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/88697
2017-12-07T19:21:45Z
2017-12-07T19:21:45Z
World’s scientists turn to Asia and Australia to rewrite human history
<figure><img src="https://images.theconversation.com/files/198087/original/file-20171207-31528-1ivvv02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Indigenous Australians created elaborate rock art, as shown here in Arnhem Land. </span> <span class="attribution"><span class="source">P. Taçon </span>, <span class="license">Author provided</span></span></figcaption></figure><p>Where did we humans come from? </p>
<p>Some 40 or so years ago, our origins seemed quite straight forward. </p>
<p>But now we see that the human story is far more complex. As summarised by Christopher Bae and colleagues in their <a href="http://dx.doi.org/10.1126/science.aai9067">latest paper just published in Science</a>, data from Asia and Australia is becoming vital in piecing this new history together.</p>
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<h3>Zoom using +/- and click on each site to view more information. The box at top left can also be used to navigate through the evidence.</h3>
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Read more:
<a href="https://theconversation.com/curious-kids-where-did-the-first-person-come-from-85891">Curious Kids: Where did the first person come from?</a>
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<p>The original story went something like this: modern humans (<em>Homo sapiens</em>) evolved to their current anatomical form in sub-Saharan Africa sometime after 200,000 years ago. They hung around for a bit, then groups started moving out of the homeland. </p>
<p>Arriving in Western Europe, a “human revolution” soon occurred (40,000 years ago), resulting in our much celebrated artistic and complex language abilities, a sort of creative explosion. These cognitively and technologically advanced peoples then out-competed the indigenous Neanderthals (and other archaic, or relatively ancient, human groups) and ultimately conquered the entire globe. </p>
<p>But fresh evidence has forced a rethink of this version of human history. </p>
<h2>Modern humans</h2>
<p>New analyses of human fossils have pushed back our earliest recognisable modern ancestors to around 310,000 years. And they weren’t found in eastern or southern Africa (like previous fossil finds), but from a site called <a href="https://www.nature.com/articles/nature22336">Jebel Irhoud in Morocco</a>. These findings have raised questions regarding exactly how – and where – we became “modern”. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/qEk_sNYAyCo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Chimpanzees fish for algae using tools.</span></figcaption>
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<p>Traditionally, we saw the primary difference between humans and the rest of the animal kingdom as being the use of tools. However, primatologists and other biologists have been recording more and more instances of <a href="http://www.sciencedirect.com/science/article/pii/S000334721000343X">chimpanzees</a>, orangutans, and other creatures making and using tools.</p>
<p>More than that, work initially in southern Africa has demonstrated that the creative explosion didn’t happen in Europe – it happened back in Africa, and far before the original 40,000 years ago date. </p>
<p>Currently, we understand that our complex cognitive and social capacities first began to emerge at around 100,000 years ago or earlier. And it wasn’t even an explosion, but probably more like a slow burn that slowly built into the raging fire of modern creativity. </p>
<h2>New and old humans</h2>
<p>Perhaps the most intriguing new evidence comes from the analysis of ancient DNA samples. </p>
<p>These studies are showing that interactions between the “new” humans (Modern Humans like you and me) and the “old” humans (<a href="http://science.sciencemag.org/content/328/5979/710">Neanderthals</a>, <a href="https://www.nature.com/articles/nature09710">Denisovans</a>, <em><a href="https://www.nature.com/articles/nature13962">Homo erectus</a></em>, <em><a href="https://theconversation.com/the-hobbit-took-our-breath-away-now-its-the-new-normal-60784">Homo florensiensis</a></em>, that are all now extinct) was not just a case of simple replacement. Instead, it appears that groups of new and old humans intermingled, <a href="https://www.nature.com/articles/nature14558">interbred</a>, <a href="https://www.smithsonianmag.com/science-nature/ancient-brutal-massacre-may-be-earliest-evidence-war-180957884/">fought</a>, and interacted in a multitude of different ways which we are still disentangling.</p>
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Read more:
<a href="https://theconversation.com/neanderthals-didnt-give-us-red-hair-but-they-certainly-changed-the-way-we-sleep-85173">Neanderthals didn't give us red hair but they certainly changed the way we sleep</a>
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<p>The results of these encounters appear to have left some lasting legacies, like the presence of between 1-4% <a href="http://www.sci-news.com/othersciences/anthropology/science-neanderthal-genes-modern-human-dna-01734.html">Neanderthal DNA in non-African Modern Humans</a>. </p>
<p>These studies are also beginning to identify some interesting cognitive differences between “us” and “them”, such as the fact that while we modern humans are susceptible to brain conditions like autism and schizophrenia, it appears <a href="https://www.newscientist.com/article/dn25443-why-we-get-autism-but-our-neanderthal-cousins-didnt/">Neanderthals were not</a>. </p>
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<a href="https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=311&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=311&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=311&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=391&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=391&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198055/original/file-20171207-31546-1v4871g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=391&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Map of sites and postulated migratory pathways associated with modern humans dispersing across Asia during the Late Pleistocene <strong>CLICK TO ZOOM</strong>.</span>
<span class="attribution"><a class="source" href="http://dx.doi.org/10.1126/science.aai9067">Katerina Douka and Michelle O'Reilly</a></span>
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<h2>The Asian story</h2>
<p>The Australasian region is playing a larger and larger role in rewriting the stories of human history. </p>
<p>New fossils like <em><a href="https://australianmuseum.net.au/homo-floresiensis">Homo floresiensis</a></em> have completely changed our view of what the human story is in this region. These tiny humans – “the hobbits” – found on the Indonesian island of Flores, continue to challenge palaeoanthropologists – are they a <a href="https://www.nature.com/articles/534188a?WT.ec_id=NATURE-20160609&spMailingID=51562085&spUserID=MjA1NzcwMjE4MQS2&spJobID=941139164&spReportId=OTQxMTM5MTY0S0">dwarfed</a> <em>Homo erectus</em>? Or are they the descendants of something much more ancient? What are the implications?</p>
<p>But perhaps more interesting (to me at least), are the multitude of artefactual finds which have come to light in recent years. </p>
<p>It now seems that one of the species of older humans, <em>Homo erectus</em>, may have had some capability for symbolism – something rarely associated with them. This hypothesis comes thanks to new analyses of material from old excavations. </p>
<p>Looking back at material excavated from the first known locality of <em><a href="https://www.nature.com/articles/nature13962#ref2">Homo erectus</a></em> fossils – Trinil on Java, originally discovered by Eugène Dubois in 1891 – scientists stumbled upon a shell exhibiting a <a href="https://www.nature.com/articles/nature13962">zig-zag pattern</a>. This shape had been carefully inscribed using a stone tool more than 400,000 years ago (and perhaps as much as 500,000!). Such geometric motifs had previously been found at southern African sites – but all with Modern Humans – and all significantly younger. In Eurasia too, such designs are present, but rarely seen in <a href="http://www.bbc.com/news/science-environment-28967746">Neanderthal contexts</a>. </p>
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<img alt="" src="https://images.theconversation.com/files/198082/original/file-20171207-31570-a5ttjt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/198082/original/file-20171207-31570-a5ttjt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198082/original/file-20171207-31570-a5ttjt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198082/original/file-20171207-31570-a5ttjt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198082/original/file-20171207-31570-a5ttjt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198082/original/file-20171207-31570-a5ttjt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198082/original/file-20171207-31570-a5ttjt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Walking towards the Maros kast in Sulawesi — where the worlds oldest rock art is located.</span>
<span class="attribution"><span class="source">M. Langley</span>, <span class="license">Author provided</span></span>
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<p>Other findings in Island South East Asia – this time associated with modern humans, <em>Homo sapiens</em> – are showing that the realm of extravagant creativity wasn’t the sole domain of Africa and Europe. New explorations and excavations on Sulawesi and Timor-Leste have recovered not only the <a href="https://www.smithsonianmag.com/history/journey-oldest-cave-paintings-world-180957685/">oldest rock art in the world</a>, but a vast array of <a href="https://www.newscientist.com/article/2101485-oldest-jewellery-in-east-asia-is-crafted-37000-year-old-shell/">jewellery</a> and other <a href="https://theconversation.com/ice-age-art-and-jewellery-found-in-an-indonesian-cave-reveal-an-ancient-symbolic-culture-75390">artistic items</a>. </p>
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Read more:
<a href="https://theconversation.com/ice-age-art-and-jewellery-found-in-an-indonesian-cave-reveal-an-ancient-symbolic-culture-75390">Ice age art and 'jewellery' found in an Indonesian cave reveal an ancient symbolic culture</a>
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<p>More than this propensity for art, it has also been found that the first modern human colonists in Asia were practising complex food-targeting strategies, like <a href="https://www.newscientist.com/article/dn21213-deep-sea-fishing-for-tuna-began-42000-years-ago/">deep-sea fishing</a>. Such a finding indicates an extensive knowledge of the sea, its dangers, and its rewards.</p>
<h2>Focus on Australia</h2>
<p>Australia too has been contributing to the rewriting of human histories. </p>
<p>In just the last two years alone, the date of original colonisation of this vast southern continent has been pushed back to around <a href="https://www.nature.com/articles/nature22968">65,000-years-ago</a>. </p>
<p>The earliest <a href="https://www.sbs.com.au/nitv/nitv-news/article/2016/12/15/untold-story-ancient-aboriginal-bone-ornament-upended-historical-record">bone ornament</a> in the world, and the earliest <a href="http://www.abc.net.au/news/science/2016-05-11/worlds-oldest-known-ground-edge-stone-axe-fragments-found/7401728">ground-edge tool</a> in the world were both found on this continent. It is becoming obvious that Australia was (and is) a land of highly adaptive and innovative people.</p>
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<img alt="" src="https://images.theconversation.com/files/198083/original/file-20171207-31560-195hson.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/198083/original/file-20171207-31560-195hson.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198083/original/file-20171207-31560-195hson.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198083/original/file-20171207-31560-195hson.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198083/original/file-20171207-31560-195hson.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198083/original/file-20171207-31560-195hson.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198083/original/file-20171207-31560-195hson.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The earliest bone tool in Australia — and the earliest bone ornament in the world. A ‘nose bone’ ornament made from kangaroo fibulae found in Carpenter’s Gap 1, Kimberley — Bunuba country.</span>
<span class="attribution"><span class="source">M. Langley</span>, <span class="license">Author provided</span></span>
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<p>The speed at which new and astounding discoveries are being made in Australasia has effectively turned the focus of many human evolution researchers from the old bastions of Africa and Eurasia, much further east. </p>
<p>Recognising the growing importance of this region for furthering our understanding of our story, it is not only individuals that are moving their focus to Asia, but also whole departments. For example, the <a href="https://www2.griffith.edu.au/environmental-futures-research-institute/research-centre-human-evolution">Australian Research Centre for Human Evolution</a> based at Griffith University in Brisbane was launched with the expressed view of focusing on the Australasian region to answer evolutionary questions. </p>
<p>In all, it is an exciting time to be a researcher in this region. Indeed, it appears that the long sought after answers to some of the central questions in human evolution studies may finally be answered here.</p><img src="https://counter.theconversation.com/content/88697/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michelle Langley is a ARC DECRA Research Fellow at the Australian Research Centre for Human Evolution, Griffith University. She is currently receives funding from the Australian Research Council to explore the diversity and richness of Australia's bone technologies. </span></em></p>
Researchers in human evolution used to focus on Africa and Eurasia – but not anymore. Discoveries in Asia and Australia have changed the picture, revealing early, complex cultures outside of Africa.
Michelle Langley, DECRA Research Fellow, Griffith University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/79823
2017-11-29T12:18:11Z
2017-11-29T12:18:11Z
Rosie the Riveters discovered a wartime California dream
<figure><img src="https://images.theconversation.com/files/195735/original/file-20171121-6016-1umzjy8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Women shipfitters working on board the USS Nereus at the U.S. Navy Yard in Mare Island, circa 1943.</span> <span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/9/91/%22Women_shipfitters_worked_on_board_the_USS_NEREUS%2C_and_are_shown_as_they_neared_completion_of_the_floor_in_a_part_of..._-_NARA_-_296892.jpg">Department of Defense</a></span></figcaption></figure><p>For many American families, the Great Depression and Dust Bowl struck like swift punches to the gut. New Deal work relief programs like the <a href="https://livingnewdeal.org/glossary/works-progress-administration-wpa-1935/">Works Progress Administration</a> tossed lifelines into the crushing economic waves, but many young people soon started looking farther west for more stable opportunities.</p>
<p>A powerful vision of the California dream took hold in the late 1930s and early 1940s, featuring steady work, nice housing, sometimes love – all bathed in abundant warm sunshine. </p>
<p>Perhaps most important were the jobs. They attracted people to the Pacific Coast’s new airplane factories and shipyards. The Japanese attack on Pearl Harbor in December 1941 led to an intensified war effort, and more Americans sought ways to demonstrate patriotism while also taking advantage of new employment opportunities. People from economically downtrodden regions began <a href="http://vm154.lib.berkeley.edu:3002/searchinterview/display?utf8=%E2%9C%93&q=&project=Rosie+The+Riveter+World+War+II+American+Home+Front">flooding into California en masse</a> – where <a href="https://www.nps.gov/rori/learn/management/upload/3%20RORI_Chapter2Feb09.pdf">nearly 10 percent of all federal government expenditures</a> during the war were spent.</p>
<p>Following wartime opportunities west, “Rosie the Riveters” found more than just jobs, though, when they reached the Golden State. And at the war’s conclusion, each had to decide whether her own version of the California dream had been temporary or something more durable.</p>
<h2>Moving on to another life</h2>
<p>Moving to find work looms large in the historical memory surrounding the Great Depression, and migration continued in the ensuing years. The Second World War led to the <a href="https://www.nps.gov/rori/learn/historyculture/index.htm">largest mass migration within the United States</a> in the nation’s history.</p>
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<a href="https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=916&fit=crop&dpr=1 600w, https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=916&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=916&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1151&fit=crop&dpr=1 754w, https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1151&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/195723/original/file-20171121-6044-u7n24h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1151&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Posters aimed to recruit women to jobs left vacant by drafted men during the war.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:%22Do_The_Job_He_Left_Behind%22_-_NARA_-_513683.jpg">Office of War Information</a></span>
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<p>People in rural parts of the country learned about new jobs in different ways. Word of mouth was crucial, as people often chose to travel with a friend or relatives to new jobs in growing cities along the West Coast. <a href="http://kaiserpermanentehistory.org/latest/the-permanente-richmond-field-hospital-proud-reminder-of-health-cares-role-in-world-war-ii/">Henry Kaiser, whose production company</a> would open seven <a href="http://www.sfgate.com/bayarea/article/World-War-II-created-industrial-cultural-2503378.php">major shipyards during the war</a>, sent buses around the country recruiting people with the promise of good housing, health care and steady, well-paying work.</p>
<p>Railroad companies, airplane manufacturers and dozens if not hundreds of smaller companies supporting major corporations like Boeing, Douglas and Kaiser all offered similar work opportunities. Eventually the federal government even <a href="https://www.theatlantic.com/business/archive/2015/11/daycare-world-war-rosie-riveter/415650/">helped out with child care</a>. Considered against the economic hardships of the Great Depression, the promises often sounded like sweet music.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/txkMFGP6Xbk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Rosie the Riveter/World War II Home Front Oral History Project, a collaboration of the National Park Service and the Regional Oral History Office of The Bancroft Library of UC Berkeley, collected hundreds of wartime memories.</span></figcaption>
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<p>During an oral history I recorded in 2013 for the <a href="http://vm154.lib.berkeley.edu:3002/searchinterview/display?utf8=%E2%9C%93&q=&project=Rosie+The+Riveter+World+War+II+American+Home+Front">Rosie the Riveter/World War II Home Front Oral History project</a>, Oklahoman Doris Whitt remembered seeing an advertising poster for jobs, which sparked her interest in moving to California.</p>
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<p>“[T]he way I got in with Douglas Aircraft was I went to the post office, and I saw these posters all over the walls. They were asking people to serve in these different projects that were opening up because the war had started.”</p>
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<p>For a kid from the Great Plains, the notion of going to California to help build airplanes seemed like moving to another world. Whitt grew up on a farm without a telephone. Even catching a glimpse of an airplane in the sky was unusual. </p>
<p>Whitt applied and was hired for training almost immediately. She became a “<a href="https://www.nps.gov/rori/index.htm">Rosie the Riveter</a>”: one of the <a href="https://doi.org/10.1093/acrefore/9780199329175.013.55">estimated seven million American women</a> who joined the labor force during the war. Even the pay Whitt began earning while training in Oklahoma City was more than she had ever made in her life to that point. When she transferred to the West Coast and arrived in Los Angeles, Whitt felt she was living the California dream.</p>
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<p>“Oh, it was great. I remember coming through Arizona and seeing all the palm trees, and those were the first I had ever seen. They were way up in the air, and all I could do was look…. Then we got down into Los Angeles, and I was just amazed at the difference…. I just thought, ‘Oh, boy, we’re in Glory Land.’”</p>
</blockquote>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=466&fit=crop&dpr=1 600w, https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=466&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=466&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=586&fit=crop&dpr=1 754w, https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=586&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/195740/original/file-20171121-6039-ka6e48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=586&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Workers install fixtures and assemblies to a B-17 tail fuselage at the Douglas Aircraft Company plant in Long Beach.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:B17F_-_Woman_workers_at_the_Douglas_Aircraft_Company_plant,_Long_Beach,_Calif.jpg">Alfred T. Palmer, Office of War Information</a></span>
</figcaption>
</figure>
<p>Whitt began walking to work every day, to a job at an airplane factory disguised as a canning company. She helped assemble P-38 Lighting aircraft by riveting the fuselage together on the day shift. She later moved to Northern California, working as a welder at a shipyard. When I met her more than 70 years later, she still resided in California.</p>
<h2>Did California remain a living dream?</h2>
<p>Ultimately, the wartime version of the California dream proved real for some people. The <a href="https://www.nps.gov/nr/travel/wwiibayarea/intro.htm">state boomed in the war years</a>. Wartime jobs in the defense industries paid well, profoundly so for those coming from rural poverty. African-Americans, especially those working in extremely poor conditions like sharecropping farmers in the South, <a href="https://www.penguinrandomhouse.com/books/190696/the-warmth-of-other-suns-by-isabel-wilkerson/9780679763888/">moved in large numbers</a> to better their lives.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=462&fit=crop&dpr=1 600w, https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=462&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=462&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=581&fit=crop&dpr=1 754w, https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=581&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/195728/original/file-20171121-6044-1ff2dwn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=581&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Worker at Vega Aircraft Corporation in Burbank checks electrical assemblies.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:World_War_II_woman_aircraft_worker,_Vega_Aircraft_Corporation,_Burbank,_California_1942.jpg">U.S. Office of War Information</a></span>
</figcaption>
</figure>
<p>The Golden State didn’t always deliver on the promise it offered to those who moved there during World War II, though.</p>
<p>Many migrants found housing hard to find. Around shipyards, <a href="https://books.google.com/books?id=0E-GDAAAQBAJ&pg=PA103&lpg=PA103&dq=sleep+in+%22hot+beds%22+world+war+ii&source=bl&ots=b0zNg8ueEB&sig=5JcM2Zw2QZ23W-2ULzzbdEQEhlI&hl=en&sa=X&ved=0ahUKEwivhKWjqtDXAhWI5oMKHYFeBNgQ6AEIKDAA#v=onepage&q=hot%20beds&f=false">some people even shared “hot beds.”</a> Workers slept in shifts: When one roommate returned home, another would head in to work, leaving behind a still-warm bed. Unauthorized, or <a href="https://www.press.uillinois.edu/books/catalog/54gmn3pt9780252020940.html">“wildcat,” strikes</a> happened across California in spite of wartime rules intended to prevent such labor actions, suggestive of ongoing labor unrest bubbling over in a new wave of strikes happening after the war.</p>
<p>While many women moving to California stayed in relationships, some marriages came to an end as the <a href="https://doi.org/10.1086/593087">divorce rate spiked</a>. Whitt and her husband separated not long after her move to California.</p>
<p>And despite wartime factories’ outstanding productivity with women working in traditionally male jobs, <a href="https://www.historians.org/about-aha-and-membership/aha-history-and-archives/gi-roundtable-series/pamphlets/do-you-want-your-wife-to-work-after-the-war">women were mostly pushed out of their jobs</a> at war’s end.</p>
<p>Some Rosies returned to their home states. But many others did stay in California, transitioning from wartime work in defense industries to other occupations. After all, the state still offered <a href="https://www.ucpress.edu/book.php?isbn=9780520084704">more progressive social conditions</a> and a wider range of opportunities for women than could be found in many other parts of the country during the post-war era.</p>
<p>Doris Whitt stayed in California and found a job at a meatpacking company, working there for 14 years. She moved to a small town near the ocean where she lived for decades. The California dream never completely disappeared for people like Whitt, but nothing is quite as magical as those few moments when one first discovers it. In her oral history, she remembered seeing San Francisco for the first time:</p>
<blockquote>
<p>“Oh, it was fantastic. Fantastic. I’d never seen anything like it in my life. It was just like going to a whole new country, you know? And the ocean… Oh it was just fantastic.”</p>
</blockquote>
<p>The California dream continued to evolve in the postwar era, with each passing generation and each new group of migrants making it into something new.</p><img src="https://counter.theconversation.com/content/79823/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Samuel Redman received funding from the National Park Service to assist in the creation of the oral histories noted in this article. </span></em></p>
Thousands of American women moved west to take advantage of wartime employment opportunities during WWII. For some, this version of the California dream was temporary; for others, it lasted a lifetime.
Samuel Redman, Assistant Professor of History, UMass Amherst
Licensed as Creative Commons – attribution, no derivatives.