More stories

  • in

    What made us human? The fossils redefining our evolutionary origins

    Noelia de Alda
    Is it in the way we live, laugh and love? Or maybe it is our dislike of cheesy clichés? Deep within each of us, there must be something that makes us distinctly human. The trouble is, after centuries of searching, we still haven’t found it. Perhaps that’s because we have been looking in the wrong place.
    Ever since researchers began unearthing ancient hominin bones and stone artefacts, their work has held the tantalising promise of identifying the moment long ago when our ancestors made the transition to become human. Two of the most important fossil discoveries in this quest celebrate significant milestones this year. It is 100 years since the very first “almost human” Australopithecus fossil came to light in South Africa, overturning established thinking about our place of origin. And it is 50 years since the most famous Australopithecus of them all – Lucy, also known as “the grandmother of humanity” – emerged from a dusty hillside in Ethiopia. Both fossils led researchers to believe we really could identify humanity’s big bang: the time when a dramatic pulse of evolution saw the emergence of our human genus, Homo.

    But today, the story of humanity’s birth has become far more complicated. A string of discoveries over the past two decades suggests the dawn of our genus is harder to pin down than we had thought. So why did it once seem like Lucy and her ilk allowed us to define humanity and pinpoint its emergence? Why do we now find ourselves as far as ever from establishing what, exactly, a human is?… More

  • in

    What is a human? Why the split from our ancestors is so hard to define

    Noelia de Alda
    Is it in the way we live, laugh and love? Or maybe it is our dislike of cheesy clichés? Deep within each of us, there must be something that makes us distinctly human. The trouble is, after centuries of searching, we still haven’t found it. Perhaps that’s because we have been looking in the wrong place.
    Ever since researchers began unearthing ancient hominin bones and stone artefacts, their work has held the tantalising promise of identifying the moment long ago when our ancestors made the transition to become human. Two of the most important fossil discoveries in this quest celebrate significant milestones this year. It is 100 years since the very first “almost human” Australopithecus fossil came to light in South Africa, overturning established thinking about our place of origin. And it is 50 years since the most famous Australopithecus of them all – Lucy, also known as “the grandmother of humanity” – emerged from a dusty hillside in Ethiopia. Both fossils led researchers to believe we really could identify humanity’s big bang: the time when a dramatic pulse of evolution saw the emergence of our human genus, Homo.

    But today, the story of humanity’s birth has become far more complicated. A string of discoveries over the past two decades suggests the dawn of our genus is harder to pin down than we had thought. So why did it once seem like Lucy and her ilk allowed us to define humanity and pinpoint its emergence? Why do we now find ourselves as far as ever from establishing what, exactly, a human is?… More

  • in

    Bronze Age hoards hint that market economies arose surprisingly early

    A hoard of Bronze Age metal fragments from Weißig, GermanyJ. Lipták/Landesamt für Archäologie Sachsen
    Bronze Age Europeans earned and spent money in much the same way as we do today, indicating that the origins of the “market economy” are far more ancient than expected.
    That is the controversial conclusion of new research that challenges the view that elites were the dominant force in Bronze Age economies, and proposes that human economic behaviour may not have changed much over the past 3500 years – and perhaps even longer.
    Advertisement
    “We often tend to romanticise European prehistory, but the Bronze Age was not a fantasy realm where townsfolk and peasants were merely the background for some great lord providing for their needs,” says Nicola Ialongo at Aarhus University in Denmark. “It was a very familiar world where people had families, friends, a social network, marketplaces and a job, and ultimately had to figure out how to make ends meet.”
    Europeans of the Bronze Age, a period that spans 3300 to 800 BC, were not meticulous bookkeepers like people of some other ancient societies, such as Mesopotamia. But Ialongo and Giancarlo Lago at the University of Bologna, Italy, suggest that important revelations about their daily lives, and the roots of our own modern economic behaviour, can be found in the troves of metal fragments, known as hoards, that they left behind.
    Lago and Ialongo analysed more than 20,000 metal objects from hoards buried in Italy, Switzerland, Austria, Slovenia and Germany during the Bronze Age. The pieces appear in many forms, but around 1500 BC, they start to become standardised by weight, a shift that many experts believe distinguishes them as a form of pre-coinage money.
    “The discovery of a widespread measurement and weight system makes it possible to model things that have been known about for centuries in a way that they have never been modelled before,” says Ialongo. “This opens up new results to old questions, but also new questions that no one was asking before.”
    To that end, the team found that the weight values of the huge sample follow the same statistical distribution as the daily expenses of a modern Western household: small everyday expenses, represented by lighter fragments, made up the vast majority of consumption patterns, while larger expenses, represented by heavier fragments, were comparatively rare. This pattern is analogous to what you might find in an average modern wallet, with lots of smaller banknotes and very few high-value ones.
    Lago and Ialongo interpret the findings as evidence that Bronze Age economic systems were regulated by supply and demand market forces, in which everyone participates proportionally to how much they earn. This hypothesis stands in contrast to an influential view put forth in the 1940s by the anthropologist Karl Polanyi, who cast modern economies based on monetary profit as a new and distinct phenomenon from ancient economies centred around barter, gift exchange and social standing.
    Richard Blanton at Purdue University in Indiana finds the study to be credible. “The argument, I think, will prompt discussion among archaeologists and economic anthropologists, who have been labouring under false assumptions about the antiquity of market economies for decades,” he says.
    “I think this paper will beneficially add fuel to that kind of critique,” says Blanton. “For me, the paper throws a whole new light on the function of the bronze hoards and their potential for the use of bronze pieces as units of exchange.”

    However, Erica Schoenberger at Johns Hopkins University in Maryland is sceptical of the team’s conclusions. “It’s risky to assume that ordinary people in pre-modern times used money in ordinary economic ways,” says Schoenberger. “Medieval English peasants, for example, only began selling their produce for money when their lords began demanding money in place of in-kind rents and taxes. The peasants handed most – if not all – of that money directly to the lord. They sold in order to get money, but they did not use it to buy things they needed. We’re still a long way from modern economic behaviour [in the Middle Ages].”
    Lago and Ialongo hope their research will inspire specialists in other fields to develop similar work on artefacts from different regions and cultures. They suggest that market economies naturally arose across time and cultures, and that such systems are not new or special inventions of Western societies that emerged over the past few centuries.
    “Technically, we do not prove that the Bronze Age economy was a market economy,” says Ialongo. “We simply find no evidence that it wasn’t. And we simply point out the paradox: why is everyone convinced that the market economy did not exist, if everything we see can be explained by a market economy model? In other words, why should we imagine a more complex explanation, if the simplest one works just fine?”

    Topics:archaeology/economics More

  • in

    The North Star is much heavier than previously thought

    The star marking true north is a good deal heavier than we thought.

    The North Star is 5.1 times as massive as the sun, astronomers report in work submitted July 12 to arXiv.org. That value, calculated from the motion of a much fainter star that orbits the luminary, is nearly 50 percent heavier than a recent estimate of 3.45 solar masses.

    Mass profoundly affects stellar life: The more mass a star has, the faster it burns its fuel and the sooner it dies. The earlier mass estimate had suggested that the North Star, also known as Polaris, is roughly 100 million years old (SN/12/2/16). The new estimate means the star formed more recently than this, but no one has yet calculated a revised age. More

  • in

    Egyptian pyramid may have been built using a water-powered elevator

    Did the Step Pyramid of Djoser include a hydraulic lift?Peter Brown / Alamy
    The construction of ancient Egypt’s oldest known pyramid may have benefited from a water elevator capable of lifting 50 to 100 tonnes of stones at a time.
    The suggestion draws upon the fact that the Step Pyramid of Djoser – built 4500 years ago as the burial place for an Egyptian pharaoh as part of the Saqqara necropolis site – is near two dry channels, probably once active waterways. These could have supplied rainfall runoff and Nile river water to the pyramid construction site, where… More

  • in

    Neanderthal cooking skills put to the test with birds and stone tools

    A researcher plucks a bird as part of an experiment into Neanderthals’ cooking skillsMariana Nabais
    Archaeologists have cooked and prepared five wild birds using only fire, their hands and stone tools to learn more about the culinary abilities of Neanderthals. The experiment shows it took considerable manual skill for our ancient relatives to butcher animals using flint blades without injuring themselves.
    Neanderthals inhabited Europe and Asia until around 40,000 years ago. Hearths have been found at many Neanderthal sites, and we also have evidence they hunted large animals like elephants and cave lions.
    Advertisement
    Mariana Nabais at the Catalan Institute of Human Paleoecology and Social Evolution in Tarragona, Spain, says by replicating ancient activities such as cooking and butchering with the tools available at the time, scientists can gain insight into how prehistoric humans lived.
    She and her colleagues wanted to better understand archaeological bird remains associated with Neanderthals that were recovered from deposits in Portugal, which date to approximately 90,000 years ago.
    The team selected five birds that had died in a Portuguese wildlife rehabilitation centre and were of a similar size and species to those found in the archaeological deposits: two carrion crows (Corvus corone), a common wood pigeon (Columba palumbus) and two Eurasian collared doves (Streptopelia decaocto). The tools used in the experiment were flint flakes prepared by lithic technology students.
    All five birds were plucked by hand. A crow and a dove were butchered uncooked and the remaining three birds were baked on a bed of coals. The cooked birds could be easily pulled apart without stone tools, but the raw birds required considerable effort using the flint blades.
    “Palaeolithic knives were indeed very sharp, requiring careful handling,” says Nabais. “The precision and effort needed to use these tools without causing self-injury emphasised the practical challenges Neanderthals might have faced in their daily food-processing activities.”
    Once the butchering was complete, the researchers prepared the bones and then analysed them for distinctive signs caused by the stone tools and the fire. They also identified wear marks on the flint tools.
    The burn marks and tool scars were then compared with Neanderthal food remains from the Figuiera Brava and Oliveira archaeological sites, both in Portugal. Bird bones with burning stains and cut marks found at the sites align with those seen in the team’s replications, says Nabais.
    “Our experimental study demonstrated that raw birds processed with flakes show distinctive cut marks, especially around tendons and joints, while roasted birds show burn marks and increased fragility, leading to bone breakage,” she says. “These finds help distinguish human-induced modifications from those caused by natural processes or other animals, such as trampling or the activity of rodents, raptors and carnivores.”
    Neanderthals were skilled enough to catch and cook small, quick animals like birds, says Nabais. “This study highlights the cognitive abilities of Neanderthals, demonstrating their capacity to catch and process small, fast-moving prey like birds, thus challenging the traditional notion that Neanderthals were not capable of such complex tasks.”

    Sam Lin at the University of Wollongong, Australia, says experimental archaeology is like reverse engineering where you compare what happens to a modern sample with archaeological material to try to interpret what may have happened in the past.
    In this case, one of the main findings was that cooked birds don’t need tools to be prepared for eating, which could mean some bones won’t necessarily have tool scars. “They learned you can just rip a cooked wild bird apart the same way we eat a barbecue chicken,” says Lin.

    Topics:Neanderthals/cooking More

  • in

    Denisovan DNA may help modern humans adapt to different environments

    Those living in Papua New Guinea’s highlands may benefit from having Denisovan DNAMichael Runkel/Danita Delimont/Getty Images/Gallo Images ROOTS
    People living in the highlands and lowlands of Papua New Guinea have different frequencies of several Denisovan genetic variants, which may help them adapt to their local environmental conditions.
    The Denisovans were hominins that lived across eastern Eurasia for hundreds of thousands of years, giving them plenty of time to adapt to a variety of environments.

    After leaving Africa, Homo sapiens interbred with other human species, including Denisovans,… More

  • in

    The plague may have wiped out most northern Europeans 5000 years ago

    The culture that built Stonehenge suffered a mysterious population declineWirestock, Inc./Alamy
    The Neolithic culture in Europe that produced megastructures such as Stonehenge went into a major decline around 5400 years ago. Now we have the best evidence yet that this was due to plague.
    Sequencing of ancient DNA from 108 individuals who lived in northern Europe at this time has revealed that the plague bacterium Yersinia pestis was present in 18 of them when they died.
    Advertisement
    “We think that the plague did kill them,” says Frederik Seersholm at the University of Copenhagen in Denmark.
    Around 5400 years ago, the population of Europe fell sharply, particularly in northern regions. Why this happened has long been a mystery.
    Over the past decade, studies of ancient human DNA have revealed that local populations didn’t fully recover from the Neolithic decline. Instead, they were largely replaced by other people moving in from the Eurasian steppes. In Britain, by around 4000 years ago, for instance, less than 10 per cent of the population was derived from the people who built Stonehenge.
    These studies of ancient humans also revealed several cases where the plague bacterium was present. This suggested a potential explanation – the plague might have wiped out Europe’s population, allowing the steppes people to move in with little opposition.
    But not everyone agreed. Occasional sporadic plague cases are to be expected and aren’t evidence of a major pandemic, argued Ben Krause-Kyora at Kiel University in Germany in 2021. These early forms of Y. pestis were unlikely to cause a pandemic because their DNA shows they couldn’t survive in fleas, he and his colleagues wrote. Bites from infected fleas are the main way people contract bubonic plague, the form of the illness that killed people during the medieval Black Death.
    So Seersholm and his colleagues set out to find more evidence of a plague pandemic. The 108 individuals whose DNA his team managed to sequence were buried in nine tombs in Sweden and Denmark. Most died between 5200 and 4900 years ago, and they represent several generations of four families.
    There seem to have been three separate outbreaks of the plague over these generations. The last outbreak was caused by a strain with reshuffled genes that might have been much more dangerous.
    “It’s present in a lot of individuals,” says Seersholm. “And it’s all the same version, which is exactly what you would expect if something spreads very quickly.”
    The plague DNA was found mainly in teeth, which shows that the bacterium entered the blood and caused serious illness, and was probably the cause of death, he says. In some cases, closely related individuals were infected, implying person-to-person spread.
    The team suggests this could be a result of Y. pestis infecting the lungs and spreading via droplets – a form of the illness known as pneumonic plague. Recent studies also indicate that human lice can cause bubonic plague, not just fleas, so it is possible that plague bacteria spread by this route.
    “Of course, it’s worth noting that all of these individuals were buried properly,” says Seersholm, so society hadn’t broken down at this time. “If there was in fact an epidemic, we only see the very beginning of it.”

    After about 4900 years ago, the megalithic tombs seem to have been abandoned for centuries. But 10 of the sequenced individuals were buried in them much later, most between 4100 and 3000 years ago. These individuals were of steppes origin, unrelated to those who built the tombs.
    “It is 100 per cent complete replacement,” says Seersholm. “Five thousand years ago, these Neolithic people disappear. And now we show that plague was widespread and abundant at exactly the same time.”
    The researchers aren’t claiming their findings are definitive, but they do bolster the case that plague caused the Neolithic decline, says Seersholm.
    “I would say that we’ve definitely shown that it had the potential to spread within humans, and that it had the potential to kill an entire family, for example.”
    Krause-Kyora accepts that the findings show the plague was highly prevalent in this particular place and time. “Our previous explanation needs to be revised somewhat, and we can’t just talk about isolated cases,” he says.
    But there is no evidence of high prevalence in other regions, he says. And he thinks the normal burials show there was no deadly epidemic. “The results could even suggest that the Yersinia infection was more of a chronic disease over a long period of time.”
    Seersholm and his team will now look for more evidence elsewhere in Europe. But the only way to know for sure how deadly the reshuffled strain was would be to bring it back to life, he says, and that is far too risky to attempt.
    “I think that this paper will convince many colleagues who were skeptical about our previous work,” says Nicolás Rascovan at the Pasteur Institute in Paris, whose team proposed in 2018 that the plague was responsible for the Neolithic decline after finding it in two individuals from the period.

    Topics:archaeology/infectious diseases More