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    The fascinating truth about why common sense isn’t really that common

    Martin Parr/Magnum Photos
    In the 18th century, philosopher James Beattie compiled a list of 17 common-sense beliefs. A few are incontrovertible: “I exist”; “A whole is greater than a part”; “Virtue and vice are different”. But others seem unnecessarily moralising: “Ingratitude ought to be blamed and punished”; “I have a soul distinct from my body”; “There is a God”. Then, there are the scientifically contestable: “The senses can be believed”; “I am the same being that I was yesterday – or even 20 years ago”; “Truth exists”. Overall, his list seems quaint and outdated. Worse still, it gives no clear idea of what common sense is. Surely, we can do better.
    Superficially, common sense seems easy to define: it is generally seen as knowledge or beliefs that are obvious – or should be obvious – to everyone. Yet it is strangely difficult to pin down. Often portrayed as universal, it is also often claimed not to exist. With that in mind, it might surprise you to hear that nobody has tried to measure the “commonness” of this knowledge or its intrinsic properties (its “sensicality”) – until now. Shockingly, this research shows that common sense may not be common at all.

    If true, the implications are huge. From parenting to politics and from public health to law, what counts as common sense matters. Increasingly, it is also a technological issue, with computer scientists keen to instil it in artificial intelligence-driven robots to make… More

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    AI discovers hundreds of ancient Nazca drawings in Peruvian desert

    A 22-metre-long drawing depicting a killer whale holding a knifeMasato Sakai
    Hundreds of ancient drawings depicting decapitated human heads and domesticated llamas have been discovered in the Peruvian desert with the help of artificial intelligence. Archaeologists have previously linked these creations to the people of the Nazca culture, who started etching such images, called geoglyphs, into the ground around 2000 years ago.
    These geoglyphs are smaller and older than the Nazca lines and other figures found to date, which portray huge geometric shapes stretching several kilometres or wild animals about 90 metres long on average. The newly discovered images typically depict humanoid figures and domesticated animals around 9 metres long. Some even hint at human sacrifice, portraying decapitated heads and killer whales armed with blades.
    “On some pottery from the Nazca period, there are scenes depicting orcas with knives cutting off human heads,” says Masato Sakai at Yamagata University in Japan. “So we can position orcas as beings that carry out human sacrifice.”Advertisement

    Sakai and his colleagues found the smaller geoglyphs by training an AI model to look for them in aerial photos. The high-resolution photos covered an area about 10 times as large as Manhattan, which encompassed the desert plateau called the Nazca Pampa and its surroundings, located on the UNESCO World Heritage Site for the Nazca lines. The AI then produced a gridded map that categorised the probability of each grid square containing geoglyphs.
    Researchers still spent more than 2600 hours manually inspecting the highest-probability photos and doing field inspections at the sites. But they estimate the AI helped speed up the screening process by a factor of 50 “by eliminating 98 per cent of low-probability aerial imagery from consideration and providing probabilities for the remaining 2 per cent”, says co-author Marcus Freitag at IBM Research in New York.
    The researchers followed up on the AI suggestions and discovered a total of 303 figurative geoglyphs during field surveys in 2022 and 2023. Of these figures, 178 geoglyphs were individually identified by the AI. Another 66 were not directly pinpointed, but the researchers found them within a group of geoglyphs the AI had highlighted.
    An 18-metre-long drawing depicting a humanMasato Sakai
    “The AI-based analysis of remote sensing data is a major step forward, since a complete map of the geoglyphs of the Nazca region is still not available,” says Karsten Lambers at Leiden University in the Netherlands. But he also cautioned that “even this new, powerful technology is more likely to find the better visible geoglyphs – the low hanging fruits – than the more difficult ones that are likely still out there”.
    Nearly 1000 AI-identified candidates still await inspection during future field surveys, says Sakai. Such smaller geoglyphs generally appear on hillsides near winding trails and probably featured in the “ritual activities of individuals or small groups”. In contrast, the huge line geoglyphs were more likely to be the focus of community-wide rituals, he says.
    The AI screening process also offers hope for discovering geoglyphs in the broader region beyond the Nazca lines World Heritage Site, says David Beresford-Jones at the University of Cambridge. Speed is crucial because many geoglyphs “lie on the cusp of erasure through agricultural expansion, urban development and wind-power generation”, he says.

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    Genome of Neanderthal fossil reveals lost tribe cut off for millennia

    The jawbone of a Neanderthal known as Thorin, who is thought to have been part of an isolated populationXavier Muth
    Genetic analysis of a Neanderthal fossil found in France reveals that it was from a previously unknown lineage, a remnant of an ancient population that had remained in extreme isolation for more than 50,000 years. This finding sheds new light on the final phase of the species’ existence.
    The fossil, dubbed Thorin after a character in J.R.R. Tolkien’s The Hobbit, was discovered in 2015 at the Grotte Mandrin in the Rhône Valley in southern France when Ludovic Slimak of the Centre for Anthropobiology and Genomics of Toulouse uncovered some teeth in the cave’s soil. The skeleton was painstakingly excavated over the next nine years to reveal 31 teeth, the jawbone, part of the skull and thousands of other bone fragments.
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    This was an incredible discovery in itself, as remains of Neanderthals – who lived in Eurasia from around 400,000 years ago until they went extinct around 40,000 years ago – are exceedingly rate.
    Even more surprising was that Thorin’s genome could be obtained from a fragment of one of his teeth, as DNA isn’t typically preserved in warm climates. This revealed that the fossil was from a male, but opened up a mystery that took years to solve.
    By comparing his genome with those of other Neanderthals, Slimak and his colleagues estimated Thorin lived around 105,000 years ago. However, archaeological evidence and analysis of the isotopes in his bones unequivocally showed that Thorin lived no more than 50,000 years ago – making him a “late Neanderthal” from the final phase of the species’ existence.
    “For a very long time we [geneticists] were convinced that Thorin really was an early Neanderthal, just because his genetic lineage was so distantly related to contemporary Neanderthals in the same region,” says team member Tharsika Vimala of the University of Copenhagen. “On the other side, the archaeologists were convinced that he was a late Neanderthal. It took years of work from both sides to get to the answer.”
    Eventually, the researchers realised that they must have discovered a hitherto unknown lineage of Neanderthals. Thorin was part of a small group who lived between 42,000 and 50,000 years ago. The group seems to have been a remnant of a far more ancient Neanderthal population that diverged from the main Neanderthal population around 105,000 years ago, and had then stayed genetically isolated for more than 50,000 years.
    The bones of Thorin during excavation at Grotte Mandrin in FranceLudovic Slimak
    Thorin’s DNA showed no evidence of interbreeding between his lineage and that of the main Neanderthal population, despite living in close proximity. “Thorin was completely divergent from any other Neanderthals,” says Slimak.
    This isolation could have made the group particularly vulnerable. “Long term isolation or inbreeding can be detrimental to a population’s survival as it can reduce the genetic diversity over time, which in turn can have negative effects on our adaptability to changing environments,” says Vimala.

    Slimak, Vimala and their colleagues then re-analysed the genome of another Neanderthal that had lived around 43,000 years ago at Les Cottés, France. They found traces of a “ghost population” in its DNA from a breeding event some 15,000 to 20,000 years previously, with another unknown Neanderthal group.
    “This means that there must have been not only two populations among late Neanderthals, but very likely three,” says Slimak. Previously it had been thought that at the time before their extinction, the Neanderthals were all part of one genetically similar population.
    “The evidence from Grotte Mandrin is fascinating as it gives some intriguing insights into these late Neanderthal populations and their dynamics,” says Emma Pomeroy at the University of Cambridge.

    Topics:Neanderthals/fossils More

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    Ancient people of Easter Island made return trips to South America

    Easter Island’s famous moai statuesTero Hakala/Shutterstock
    DNA analysis of ancient remains from Easter Island shows that the population was in fact increasing when Europeans arrived, rather than collapsing as reported by some historical accounts.
    The results also show that there were interactions between the residents of the island and those of South America long before the arrival of Europeans. Both the island and its people are also known as Rapa Nui.
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    Located in the Pacific Ocean 3500 kilometres from South America, Rapa Nui is one of the most remote inhabited islands on Earth. Polynesian people began settling there around AD 1200, when its 164 square kilometres were covered in palm forests.
    By the time Europeans arrived in 1722, the vegetation had been largely destroyed by a combination of rats and overharvesting. The history of the island has often been portrayed as an example of unsustainable ecological exploitation and population growth followed by collapse.
    In the latest study, J. Víctor Moreno-Mayar at the University of Copenhagen, Denmark, and his colleagues looked at 15 sets of human remains kept at the National Museum of Natural History in Paris, France, collected by expeditions in 1877 and 1935.
    The researchers worked closely with representatives of the Rapa Nui community. One of their aims was to confirm that the individuals at the museum were, in fact, from the island, as there is an effort being led by modern residents to repatriate the remains.
    The results show that the 15 people, who all died over the past 500 years, did originate on Rapa Nui.
    A population undergoing a bottleneck from a collapse in numbers will have signals in their DNA showing a drop in genetic diversity, says Moreno-Mayer.
    “We are using statistical methods that can reconstruct the genetic diversity in the Rapa Nui population throughout the last few thousand years,” he says. “And interestingly enough, we do not find any evidence of a dramatic population decline around 1600s as expected from the collapse theory.”
    Instead, the results suggest that the Rapa Nui population increased steadily until the 1860s, when slave traders kidnapped hundreds of islanders and a smallpox outbreak killed many more.

    The study also identified stretches of DNA in the ancient Rapa Nui genomes that have an Indigenous American origin. Their analysis suggests that the mixing of these populations occurred around the 1300s.
    “Our interpretation is that the ancestors of Rapa Nui first peopled the island and shortly after made a return journey to the Americas,” says Moreno-Mayer.
    Previous studies have also cast doubt on the story of a population collapse. Carl Lipo at Binghamton University in New York says it was “terrific” to learn that a completely independent line of evidence points to the same conclusions his team reached in a paper published earlier this year, using radiocarbon and archaeological evidence.
    He says the study confirms that the island was populated with people who lived resiliently and successfully until the arrival of Europeans.

    Topics:DNA/history More

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    When did humans leave the trees for the savannah – or did they at all?

    Australopithecus family in a grassy forestHistoric Collection / Alamy
    This is an extract from Our Human Story, our newsletter about the revolution in archaeology. Sign up to receive it in your inbox every month.
    It’s a truism in human evolution that we came down from the trees and out into more open country like grassy savannahs. The open grasslands are supposed to be more favourable habitats for hominins like us. In contrast, dense tropical forests have been thought of as “hostile, unfavourable frontiers” that were “too hostile for humans throughout much of prehistory” (according to a 2022… More

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    Greenland voyage sheds light on little-known ancient Arctic culture

    Researchers survey archaeological features in Wandel Dal valley, GreenlandFuuja Larsen
    Some 4500 years ago, as the Great Pyramid of Giza was being erected and the Indus Valley civilisation hit its peak, a group of Arctic peoples migrated to a region of northern Greenland now known as Inutoqqat Nunaat, or the “land of the ancient people”.
    They were the northernmost culture on Earth at the time, living just 800 kilometres from the North Pole, but little else has been known about their diet, customs and strategies for survival in this polar climate. Now, that is starting to change. More

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    A gripping account of morality shows how we work out right from wrong

    The trolley problem is a classic dilemma in moral philosophyStefan Lenz/Getty Images
    Animals, Robots, GodsWebb Keane (Allen Lane)
    No society we know of ever lived without morals. Roughly the same ethical ideas arise, again and again, over time and in different societies. Where do these notions of right and wrong come from? Might there be an ideal way to live?
    In Animals, Robots, Gods: Adventures in the moral imagination, anthropologist Webb Keane at the University of Michigan argues that morality doesn’t arise from universal principles but from the human imagination. For him, moral ideas are sparked in… More

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    This blend of spy caper and climate fiction is top-notch

    The action in Creation Lake is based in Guyenne in south-west FrancePhotononstop/Alamy
    Creation LakeRachel Kushner (Jonathan Cape (UK, 5 September); Scribner (US, 3 September))
    Creation Lake by Rachel Kushner is a thriller, a spy caper, a comedy and also a poetic take on human history all the way back to the time our species, Homo sapiens, shared Earth with the Neanderthals. It is a sensationally enjoyable novel and has deservedly made the Booker prize longlist.
    The story is narrated by our anti-hero, Sadie Smith (not her real name). She is a US undercover operative working for shady employers… More