Humans

Michael Kirkham
I am an only child. Saying this sometimes feels like a confession – not least when people respond with a well-meaning “oh, you don’t seem like it!”. Now, as the mother of a preschooler, I see my daughter navigating the same assumptions. “Does she have older siblings?” one teacher asked recently. “She plays so well with the other kids!”
If it seems like I am bragging about my (or my daughter’s) behaviour, you will have to excuse me: I am, after all, an only child.
For over a century, we have been seen as odd, at best; antisocial, neurotic and narcissistic, at worst. “Being an only child is a disease in itself,” declared 19th-century child psychologist Granville Stanley Hall.

Whether there are actually any differences between the personalities and well-being of singleton children and those with siblings remains a contentious question – one given fresh impetus by the growing trend of one-and-done parenting.
Single-child families have become more common since the 1970s in high-income countries, including the US and UK, whether “by constraint or by choice”, says éva Beaujouan, a demographer at the University of Vienna, Austria. In Europe, nearly half of all households with children have just one child.
Despite their growing popularity, one-child families continue to encounter a long-held view that this arrangement is somehow harmful. Fortunately, delving into contemporary research can offer a degree of clarity – and it hints that being an only child can come with surprising outcomes. The findings may offer some reassurance for one-and-done parents and those still debating how many… More

The Xingu Indigenous Territory in the Amazon may contain over 900 square kilometres of dark earthLeo F Freitas/Getty Images
Rich soil in the Amazon cultivated over centuries by Indigenous communities may store billions of tonnes of carbon, suggesting that the rainforest plays an even larger role in stabilising the global climate than previously thought.
The soil, known as “terra preta” or “dark earth” for its distinctive colour, is formed by people spreading ash and other organic waste around settlements. It is more fertile than the region’s typically sandy, nutrient-poor soils, and stores around double the carbon. In some areas,… More

A humerus fragment excavated at Mata Menge in Flores, IndonesiaYousuke Kaifu
Hominins living on an Indonesian island 700,000 years ago were even smaller than Homo floresiensis, the so-called hobbits that lived on the same island much more recently. Newly analysed fossils may represent the hobbits’ ancestors – but the evolutionary story of these small-bodied hominins is still shrouded in mystery.
Fossils of H. floresiensis were first discovered in 2003 in Liang Bua cave on the island of Flores. The hobbit bones date from between 90,000 and 50,000 years ago.
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In 2016, Yousuke Kaifu at the University of Tokyo and his colleagues uncovered hominin remains from Mata Menge, an open-air site further east on Flores that was once a riverbed. The remains are about 700,000 years old and include part of a skull, a piece of jawbone and six teeth, all unusually small for a hominin.
The obvious interpretation was that the Mata Menge hominins were the ancestors of the hobbits. But because the remains were so fragmentary, it wasn’t possible to be confident.
Kaifu and his colleagues have now described three new remains from Mata Menge: two teeth and, crucially, a piece of an upper arm bone, or humerus. With this limb bone, “we could finally determine the body size,” says Kaifu.
Unfortunately, the humerus isn’t complete: the shaft is snapped. To determine exactly how far along the break occurred, the team looked for key markers, including a groove that supports a nerve and the attachment point for a muscle. Using these clues, they determined that the bone had broken about halfway along – enabling them to estimate its total length as between 20.6 and 22.6 centimetres.
There are telltale features of the microstructure of the bone that confirm it is from an adult. Extrapolating from the humerus to the entire body, the team estimates the Mata Menge hominin was between 93 and 121 cm tall, with a best estimate of 100 cm. That is a little shorter than the H. floresiensis specimens from Liang Bua, which Kaifu says were at least 6 cm taller – and would make it the smallest adult hominin ever found.
The findings point to a likely explanation for the evolution of H. floresiensis, says Kaifu. It has long been suspected that the species was descended from large-bodied hominins called Homo erectus, which are the first hominin species known to have lived outside Africa – including on Java in Indonesia about a million years ago. “I’m almost sure that they are derived from those populations,” says Kaifu. This is because of similarities between the teeth from Mata Menge and those of H. erectus from Java, and the close proximity of the dates and locations.
The suggestion is that a small population of H. erectus reached Flores, possibly by accident, and lived there in isolation. They must have then evolved a smaller body size within 300,000 years, says Kaifu. “They were small early and then they remained small for a long, long time,” he says.
It’s common for island-dwelling animals to shrink through evolution, because food resources are limited and the lack of large predators means there’s no advantage to being bulky. In line with this, Flores was home to dwarf elephants and other species that had shrunk over many generations.

However, there are alternative explanations, according to Debbie Argue at the Australian National University in Canberra, author of Little Species, Big Mystery: The story of Homo floresiensis.
Argue points out that the Mata Menge teeth don’t look especially similar to the H. floresiensis teeth from Liang Bua. For instance, a molar from Mata Menge has five pointed “cusps”, while H. floresiensis molars have four. “There’s no clear indication of anyone evolving into anyone else,” she says, and it’s not clear why the later H. floresiensis would have evolved slightly larger bodies than their Mata Menge ancestors. Furthermore, “there’s no evidence for Homo erectus from the island.”
For these reasons, Argue says we shouldn’t assume that the Mata Menge hominins are the ancestors of the hobbits. “I would be considering another hypothesis, that the Mata Menge hominins are a new unknown species.” If island life could cause one hominin population to evolve smaller bodies, it could do so twice, she suggests.
In 2017, Argue and her colleagues compared H. floresiensis with other hominins and concluded that their closest known relatives weren’t H. erectus, but instead an older species called Homo habilis, which is only known from Africa. On this basis, they proposed that H. floresiensis actually evolved in Africa, from the same ancestral population that gave rise to H. habilis. Later, some of them migrated east, ending up on Flores. Argue says we probably need more fossils to resolve the question of the hobbits’ origins.

Topics:human evolution/ancient humans More

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

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

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.
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“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

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

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.
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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