Humans

Ferran Traite Soler/Getty Images
“I’ve always prided myself on my can-do attitude,” a reader told me this month. “Recently, however, I’ve started to feel resentful of the amount of work my boss puts at my door compared to colleagues. The more I do, the more he seems to expect of me, and I now feel that I’m cracking under the stress.”
Our reader’s frustration is surely justified. A good work ethic should be one of the most highly prized – and rewarded – qualities in an employee. Everyday experience, though, reveals this is rarely the case. Indeed, according to studies by Matthew Stanley at the National University of Singapore and his colleagues, a pernicious bias can lead managers to exploit the very people they should be prizing.
In one experiment, a group of managers were asked to read about a fictional employee named John, whose company was facing financial difficulties. They had to decide how willing they would be to give John extra hours and responsibilities without any extra pay. The researchers found that the managers were far more willing to do so if they learned that John had proved to be a loyal member of the team – compared with someone who was known to be more detached from their work.
Further studies confirmed that small displays of loyalty encouraged managers to take this attitude: the more “John” gives, the more his managers will take. As Stanley and his co-authors note, this could create a “vicious cycle” of suffering – while less loyal workers manage to escape the sacrifices. But before you start viewing your boss too harshly, it is worth noting that Stanley and his colleagues don’t believe that the managers are conscious of their behaviour, instead regarding this as a form of “ethical blindness”.
This may be compounded by the fact that many of us struggle to turn down extra responsibilities for fear of seeming disagreeable. If we are to break free from that pattern of behaviour, we need to learn how to say no. Research by Vanessa Bohns at Cornell University in New York state suggests it is easier to do so by email than in voice-to-voice or face-to-face conversations. If the request comes in person, or on the phone, I have found that it helps to ask whether you can check your schedule before agreeing. That small delay should prevent a knee-jerk “yes”, and if you want to refuse, it gives you time to formulate a polite response. Try to use assertive language. Saying “I don’t have time” is more persuasive than “I can’t make time”, for example, since it is simply reflecting the reality of your situation, rather than apologising for your inability to create more hours in the day.
But I can’t help think the onus should be on our managers to change their behaviour. A little self-awareness about their tendency to exploit their hardest workers might lead them to rethink how they reward that loyalty.

Vanessa Bohns’s book You Have More Influence Than You Think (W. W. Norton) explores the psychology and ethics of compliance, including many strategies to become more assertive.

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David Robson is an award-winning science writer and author of The Laws of Connection: 13 social strategies that will transform your life

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Elaine Knox
When I was growing up, it was customary for children to join the scouts once they reached fifth grade, around the age of 9 or 10. My parents bought me the scout uniform with the matching scarf and leather loop to fasten it around the collar, and I still remember feeling special and grown-up as I wore the uniform to the local scouts chapter.
We all formed a circle, sitting cross-legged on the ground as the group leader sat on a small stool and addressed us very seriously. When he finished talking about what it meant to be a junior scout, he told us to stand to attention as he recited the scouting pledge, and we repeated it solemnly after him.

As I said the words out loud, I knew for the first time that I was different. While the other kids seemed awed by this initiation – by the sacred bond forged with their fellow inductees and all those who had come before them – I felt nothing. They were just words.
Most people find it hard to imagine what it is like to not feel any particular affinity or loyalty towards any group. This is so unusual that it is understood by some as a psychological problem to be treated. However, over my 40 years as a clinical psychiatrist I have realised that for many of my patients (and for me) disinterest in group membership and assimilation isn’t a psychological problem – it is simply a personality type that hasn’t been recognised before.
Otroverts is the term I use for those who don’t feel the obligation to merge their identities with others. We are all born as otroverts, before the cultural conditioning of childhood cements our affiliations with various identities and groups.
Being unable to adopt a group identity can have social consequences in a culture that is designed for joining. However, it can also be quite advantageous. When you don’t belong to any group, you aren’t subject to the group’s implicit rules or swayed by its influence. This confers two beneficial traits: originality and emotional independence.
Being outside the hive, so to speak, allows you to think and create freely: to come up with unique ideas, untainted by groupthink or by what has come before. Able to distinguish between the gravitational pull of the group consensus and your own inner, personal centre of gravity, you are free to think whatever you want and to be flexible when situations change, without fear of subverting collective notions about what makes an idea “good”.
Given that you can’t be cast out of a group to which you don’t belong, you have no fear of such social rejection. You don’t seek external validation, nor do you rely on others for emotional support. You don’t feel the need to convince anyone of anything, least of all your own worth.

Our communal society often conflates belonging with connection. However, while it is true that people who struggle to connect might find it hard to achieve a sense of belonging, it isn’t true that not belonging means no connections at all. In fact, without the noise of popular culture, gossip, family conflicts or political tribes (all disinteresting to otroverts), you are free to focus on deepening bonds with the people you feel genuinely close to.
History is full of independent thinkers who aren’t emotionally dependent on any group and can therefore see the fanaticism of a hive mind long before most people do: George Orwell comes to mind.
Sadly, it often seems that people need to emerge from the ashes of self-destructive groupthink before they realise that individual thinkers can be right.
Perhaps we can learn from otroverts that, while there are many reasons to praise community, we should also be acutely aware of its darker side – tribalism.
Rami Kaminski is a psychiatrist and author of The Gift of Not Belonging

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A model of an Australopithecus homininCredit: Cro Magnon/Alamy
Thirteen hominin teeth have been discovered in Ethiopia in layers of volcanic ash between 2.6 and 2.8 million years old. The researchers think some of the teeth belong to one of the earliest members of the Homo genus, while others appear to be from a new hominin, suggesting both species lived alongside each other.
“They either shared resources, and everything was hunky-dory, or maybe one of them was marginalised,” says Kaye Reed at Arizona State University. “We just don’t know at this point.”

Previous discoveries show that before around 3 million years ago, several species of early hominins in the genus Australopithecus lived in this region, including Australopithecus afarensis, the species to which the famous Lucy fossil belonged.
From around 2.5 million years ago, the first hominins from the genus Homo start appearing, with features more similar to those of modern humans. So what happened in between? To find out, Reed and her colleagues have been digging in an area called Ledi-Geraru, where there are volcanic deposits from this crucial time.
In 2013, her team found a 2.8-million-year-old jaw that appears to be from a Homo species, pushing back the origin of this genus. Now her team has found 13 teeth in three different layers of ash.

The teeth in the oldest and the youngest layers – which are dated to 2.79 and 2.59 million years ago – also belong to the genus Homo, according to the team. But they think the teeth in the middle layer – which is dated to 2.63 million years – are from an Australopithecus. The sites are all within a kilometre of each other.
“We were expecting to find more of our genus Homo, and then we found Australopithecus as well,” says Reed.
Molar teeth from Ledi-Geraru, which may come from an unknown species of AustralopithecusBrian Villmoare: University of Nevada Las Vegas
What’s more, the Australopithecus teeth are different enough from those of A. afarensis and other australopithecines that the team thinks it is probably a new species. If they are right, it means the evolutionary tree leading to modern humans is bushier and more complex than we thought.
It is a great discovery, says John Hawks at the University of Wisconsin–Madison, but it is hard to draw conclusions based on a few teeth.
“When you find evidence that spans 200,000 years, as these teeth do, you can’t be sure that they lived at the same time,” says Hawks. “That’s a huge amount of time.”

The identification of the teeth as separate species is also questionable. “Many fossils that we find combine features that are sometimes found in different species. You can always take a small sample and break it up into the most Homo-like and most Australopithecus-like,” says Hawks.
“The question is what, statistically, you can say, and in this case the statistics on size measurements don’t show that the teeth are very different from each other. They’re in the range of overlap of early Australopithecus species and early Homo species.”

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The skeleton of a girl from Updown cemetary, who was found to have West African ancestryM George et al.
Two unrelated young people buried in cemeteries in England in the Early Middle Ages probably had grandparents from West Africa. How and when their relatives arrived in Britain is unknown, but the discovery implies that migrants in Anglo-Saxon times were coming from much further afield than previously thought.
After the Romans finally withdrew from Britain in AD 410, Britain was invaded and settled by Germanic Angles, Saxons and Jutes. To investigate whether people also arrived from elsewhere, Duncan Sayer at the University of Central Lancashire, UK, and his colleagues have analysed ancient DNA from the bones of people buried in two 7th-century cemeteries on England’s southern coast.

One of them is in Updown in Kent, where many traded objects from around the world have been found, including pots, buckles and brooches from Frankish Gaul, and garnets in jewellery that may have come from India. The people in the cemetery were often buried with items like cookware, cutlery or combs.
The other cemetery is in Worth Matravers, Dorset, further west. The people there are buried in a Romano-British manner, with few grave goods.
The majority of those in the cemeteries had, as expected, either northern European or western British and Irish ancestry, but a girl at Updown and a young man at Worth Matravers had a recent ancestor, likely a grandparent, from West Africa.

In both cases, the mitochondrial DNA, which is passed down from the mother, was northern European, but the autosomal DNA, which comes from both parents equally, had 20 to 40 per cent ancestry akin to that of the present-day Yoruba, Mende, Mandinka and Esan groups from sub-Saharan West Africa.
This means the West African DNA probably comes from a grandfather – and it is the first evidence for genetic connections between Britain and Africa during the Early Middle Ages.
Both young people were buried as typical members of the community. The DNA analysis also showed that two relatives of “Updown Girl”, who was about 11 to 13 years old when she died, are in the same cemetery: a grandmother and an aunt.
Looking at the ratios of isotopes of carbon and nitrogen in a bone sample from the Worth Matravers youth, who was aged between 17 and 25 when he died, showed what he had eaten when the bones were forming.
“From his diet, it looks like he was born and raised in England,” says team member Ceiridwen Edwards at the University of Huddersfield, UK.
There is evidence for African DNA in York in the Roman period, says Edwards. However, Sayer thinks the proportion of West African DNA in the youngsters in the cemeteries would be far lower if they were descendants of people from the days of Roman rule. “This is a grandparent, so it’s definitely not about surviving Roman military or administrators, which were several hundred years in the past,” he says.

There is also no evidence to suggest that these people were slaves, says Sayer: “These individuals are being buried as fully fledged members of their community.”
Instead, he suggests, this is to do with trading and the movement of goods and people. At some point, people from West Africa had come to Britain, perhaps on a trading ship, and stayed.
Sayer thinks their arrival may have been linked to the reconquest of North Africa by the Byzantine Empire, also known as the Eastern Roman Empire, in the 6th century. That military action was taken to get access to gold from sub-Saharan Africa. “The reopening of this channel is taking place at a time that would correspond very much with the grandparents of these two people,” he says.
“This work exemplifies how dynamic the post-[Western] Roman and early medieval periods were in Britain,” says Marina Soares Da Silva at the Francis Crick Institute in London. “The authors propose trading routes facilitated by the Byzantine Empire rule in North Africa, and I think that’s a valid possibility.”
Seventh-century England was certainly no “dark age” collection of small, rural, isolated communities, says Sayer. “These are dynamic communities with artefacts being traded, and gene flow taking place, all the way from West Africa and beyond.”

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Illustration of an ancient Denisovan manJOHN BAVARO FINE ART/SCIENCE PHOTO LIBRARY
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.
One of the things I try to do in Our Human Story is answer the most commonly asked questions about human evolution. Back in February 2021, I tried to explain something that bugs a lot of people: how Neanderthals and modern humans could interbreed if they were separate species. (Short answer: the boundaries between species are fuzzy).
This month we’re going to tackle another perennial source of confusion. Why don’t the Denisovans, an extinct human group that was once widespread in Asia, have a species name? And what should their name be, if they ever get one?

The question of what the Denisovans’ “official” name should be has been rumbling on ever since they were discovered in 2010. It came up again in June, when a major discovery was announced. A skull from Harbin in North China, dubbed the Dragon Man, had been identified as a Denisovan using molecular evidence. We had never had a Denisovan skull before, so this was the first time we had a good idea of what their faces were like.
When I went on New Scientist’s podcast The World, the Universe and Everything to talk about the find, host Rowan Hooper asked me why the Denisovans don’t have a species name. Why can’t we call them Homo denisovanensis or something, the way we call Neanderthals Homo neanderthalensis?

Time was short, so I gave what I hoped was a simple answer: “It comes down to the fact that we have never had enough information about the Denisovans to be able to describe them properly… Their DNA is as different from Neanderthals as Neanderthal DNA is from us. Just on that basis, they’re different enough to count as a new species. But that’s not enough, according to the official rules of scientific taxonomy. You can’t just say, ‘That’s a new species’. You actually have to be able to describe in detail what the species looked like, what its skeleton was like. And we’ve just never had that.”
While that’s true, there’s also a lot more to it. There are two entangled questions. First, which fossils are actually Denisovans (and which aren’t)? That’s a question about objective reality, and very tricky to resolve, because it involves considering dozens of fossils and decades of research. Second, which of the many names that have been assigned should actually take precedence according to our rules of taxonomy? That’s a legalistic question about human processes – and thus even trickier.
Who’s in and who’s out?
First, here’s a reminder about the Denisovans. They’re a mysterious group of humans, first described in 2010 on the basis of a sliver of finger bone found in Denisova cave in the Altai mountains of Siberia. DNA from the bone revealed it was neither a modern human nor a Neanderthal, but something different. Furthermore, many people today carry some Denisovan DNA, especially in South-East Asia and Melanesia – indicating that Denisovans and modern humans interbred.
This implied that Denisovans must have been fairly widespread in east Asia within the last few hundred thousand years. So where are all the Denisovan fossils?
Fast forward 15 years to the present, and a small number of Denisovan fossils have been positively identified. For instance, a lower jawbone was found in a cave on the Tibetan plateau, and was identified using both proteins from the fossil and DNA from sediments. Likewise, a jawbone was dredged from the Penghu channel off the coast of Taiwan: in April, preserved proteins confirmed it was Denisovan.
Still, we are a long way from having a complete skeleton. The identification of the Harbin skull as a Denisovan took us a step closer by giving us a face. But there’s still a whole lot of skeleton still to find.
Now, there are a great many hominin fossils from East Asia that could, in theory, be Denisovan. Many of the finds have proved hard to classify: they don’t seem to quite match modern humans, or Neanderthals or any of the other established species like Homo erectus. This is enticing: if enough of them prove to be Denisovan, we’ll have a much more complete picture and maybe we could formally describe the species.
But how do we decide which fossils are Denisovan? Ideally, we’d have molecular evidence – preserved DNA or proteins – we could compare to the original Denisovan remains. But most of the specimens either haven’t been analysed or haven’t yielded anything.

One of the most prominent attempts to solve this problem was a preliminary study posted in 2024, with revisions in March, by a group led by Xijun Ni at the Chinese Academy of Sciences in Beijing. The team compared 57 hominin fossils, looking at as many physical traits as possible. This enabled them to draw up a family tree of all the various fossils.
Ni’s team found Eurasian hominins clustered into three main groups: modern humans, Neanderthals and a third group. This third group included the original Denisovan fossils, the jawbone from the Tibetan cave, the Penghu jawbone and the Harbin skull. It seems like the third group is the people we’ve been calling the Denisovans.
This is very neat if it’s true – but of course others disagree.
One contentious set of fossils comes from Hualongdong in South China. It’s a good collection: a nearly-complete skull with 14 teeth, an upper jaw, six isolated teeth and other bits. They’re all about 300,000 years old.
Ni’s team identified the Hualongdong fossils in the Denisovan group. However, a study in July led by Xiujie Wu, also at the Chinese Academy of Sciences, took a close look at the Hualongdong teeth. It found they didn’t match anything terribly well, and suggested they might represent yet another group. Of course, there’s another possible explanation: Denisovans were surely diverse, so maybe the Hualongdong Denisovans were a bit different from those elsewhere.
Meanwhile, there are many other mysterious Asian fossils, including the 260,000-year-old Dali skull and the also-260,000-year-old Jinniushan partial skeleton – both of which Ni’s team suggested were Denisovan.
At any rate, we have a growing list of Denisovan fossils, some more confidently identified than others. What are we going to call them?
The Harbin skullHebei GEO University
Homo whatever
It so happens Ni was one of the researchers that described the Harbin skull in 2021. The team named it Homo longi. So maybe that’s what we ought to call the Denisovans?
But wait. A competing proposal was put forward last year, by Wu and Christopher Bae at the University of Hawai’i at Mānoa in Honolulu. In two papers, in Paleoanthropology and Nature Communications, they argued we should instead build a species around a set of fossils from Xujiayao in northern China. They proposed calling this new species Homo juluensis and including the original Denisovan fossils. So we should call the Denisovans Homo juluensis.
The selling point of this idea is the Xujiayao fossils do resemble the Denisovan fossils. In fact, Ni’s team also classed them as Denisovan. The difference is Bae and Wu wanted to treat the Xujiayao fossils as the “type specimen”, the one that the entire species gets named after.
This is simultaneously an argument about which fossils should be grouped together and about naming conventions. Let’s separate the two.
On the first front, the Homo juluensis proposal has a big problem. Bae and Wu explicitly said the Harbin skull isn’t a Homo juluensis/Denisovan, because it doesn’t look similar enough. However, the study from June clearly shows, using molecular evidence, the Harbin skull is a Denisovan. So as a description of the objective reality – which fossils are and are not Denisovan – Homo juluensis seems to have fallen flat.
What about taxonomy? The rules here are complicated. One key element is, essentially, first come first served: the first name to be applied is considered to have priority. On this basis, Homo longi has the advantage over Homo juluensis, because it was put forward three years earlier.
Are there any other possible names for the Denisovans?
The excavators of Denisova cave never formally described the Denisovans as a species. One member of that team, Anatoly Derevianko, referred to them as Homo sapiens altaiensis, which would make them a subspecies of modern human – but he didn’t do a formal description so it apparently doesn’t count.

This year, Derevianko has put out a series of papers proposing what Denisovans might have done in Mongolia, Uzbekistan, Tajikistan and Iran. He refers to them throughout as Homo sapiens denisovan. I haven’t been able to read the papers as only the abstracts are publicly available, so I don’t know if he has provided a formal description – but if he did, he did so four years after Homo longi was named.
If you really dig around, you can find a few more options. A 2015 paper uses Homo denisovensis and a 2018 study plumps for Homo denisensis. Neither has been widely accepted.
Finally, there’s the possibility of a really old name. Maybe someone named one of the Asian hominin fossils decades ago in an obscure paper: if that fossil turns out to be Denisovan, that name would have priority (assuming the description was done properly). However, Wu, Bae, Ni and others looked into this in a 2023 paper. They found key fossils were never properly named. There had been loose suggestions that, for example, the Dali skull could be called Homo daliensis, but these were throwaway remarks rather than formal descriptions.
At this point your head is probably spinning from all these fossil names and species names, so let’s sum up. The main point is we are fleshing out our understanding of the Denisovans – and that means we’re getting closer to being able to give them a taxonomic name.
For what it’s worth, based on my understanding of taxonomic rules, I think Homo longi has a good chance of becoming the official name. I’m not sure it would have been my choice, but it isn’t up to me. In any case, they’ll always be the Denisovans to me.

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Cut marks on a foot bone from El Mirador cave in SpainIPHES-CERCA
Butchered human remains found in a cave in northern Spain suggest that Neolithic people may have eaten their enemies after killing them in combat.
Francesc Marginedas at the Catalan Institute of Human Paleoecology and Social Evolution (IPHES) in Tarragona, Spain, and his colleagues studied 650 fragments of human remains belonging to 11 people, which were found in El Mirador cave in the Atapuerca mountains and dated back 5700 years.

All of the bones had signs that these individuals had been eaten by fellow humans. Some had chop marks, indicating that the people’s skin was cut off with stone tools, while others were translucent with slightly rounded edges, suggesting they had been boiled. Some of the longer bones had been broken open with stones, probably to extract and eat the marrow, while smaller ones like metatarsals and ribs featured human teeth marks.
The study adds to evidence that cannibalism was more common than previously thought throughout human history.
El Mirador is at least the fifth site with strong evidence of cannibalism in Spain in the Neolithic period, when people switched from foraging to farming, says Marginedas. “We are really starting to see that this kind of behaviour was more common than what we expected.”

Why humans ate each other so much is less certain. At some sites, evidence including skull cups suggests that cannibalism may have had a ceremonial purpose. At others, it appears to have been a means of survival during extreme famine.
Marginedas and his colleagues say the evidence at El Mirador instead points to war. An abundance of animal remains and no signs of nutritional stress in the humans indicate this early farming community didn’t face famine, the researchers say. They found no telltale signs of ritual, with the human remains mixed in with animal bones.
The age of the individuals ranged from under 7 to more than 50 years old, suggesting a whole family had been wiped out in conflict. Radiocarbon dating revealed that all 11 people were probably killed and eaten in a matter of days.
The researchers say this mirrors signs of conflict and cannibalism also seen at two other Neolithic sites: Fontbrégoua cave in France and Herxheim in Germany. This period increasingly looks like it was defined by instability and violence, as communities clashed with neighbours or newly arrived settlers over territory.

Marginedas and his colleagues are less sure why these people then ate their adversaries, but ethnographical studies of humans eating each other in war throughout history suggest cannibalism was a form of “ultimate elimination”. “We think this one group killing the other group and then consuming it is a way of humiliating them,” says Marginedas.
“The degree to which the remains were processed and consumed is striking,” says Paul Pettitt at Durham University in the UK. “Whether or not they were consumed by kin or strangers, the violence practised on these remains is redolent of a process of dehumanisation during the process of consumption.”
Silvia Bello at the Natural History Museum in London agrees the deaths were probably the result of conflict, but isn’t convinced they were eaten as a form of humiliation. While the cannibalism may have been fuelled by aggression or hatred rather than kindness, as one would expect in funerary practices, it could still have been ceremonial, she says.
“I think it could be more complicated. Even if it was warfare, the fact that they eat them still has a sort of ritualistic meaning,” she says.

Neanderthals, ancient humans and cave art: France

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Patrick Reymer
In 1881, zoologist John Murdoch took part in an expedition to Point Barrow, Alaska, at the northernmost tip of the US. The goal was to conduct a two-year, unbroken observation of meteorological and magnetic phenomena and to document the nature and wildlife of the Arctic along the way. Travelling north through Alaska, Murdoch and his crew witnessed a peculiar act: an Iñupiat family captured two wolf pups and took them back to camp. The family carefully fed and nurtured the pups, raising them to adulthood before killing them for their fur. Murdoch was observing an ancient tradition. It turns out this Iñupiat practice might also hold the key to understanding the origin of modern dogs.  
How ancestral grey wolves were transformed into humanity’s best friend has long been debated. For the past several decades, the prevailing hypothesis has been that wolves domesticated themselves. They initiated the process by first wandering around the periphery of human settlements and feeding on rubbish tips. Over time, they became habituated to the presence of people and formed mutually beneficial relationships with them. Only then did curious humans select and breed individuals with traits like docility and gregariousness, eventually giving rise to the pet canines we know and love today.   
Through this unguided and unintentional process, wolves scavenged their way to domestication. Or so the theory goes. Recent evidence, however, has led many scientists to abandon the idea of self-domestication. If the revisionist thinking is correct, then humans, not wolves, were the driving force – and the domestication of dogs is evidence that humanity has a deep and complex relationship with wild animals that was born long ago.  

Popular perceptions of dog domestication have been shaped in large part by the late Raymond and Lorna Coppinger, who wrote a series of highly readable books on the subject at the beginning of the 21st century. The husband-and-wife team of biologists based much of their argument on “pariah” dogs that prowl human garbage dumps, feeding off leftovers and sometimes receiving direct aid from local people. “These animals are ownerless and survive largely on scraps of food waste from human settlements,” says archaeologist Loukas Koungoulos at the University of Western Australia. “They make up a majority of the species Canis familiaris worldwide – in some estimates up to 70 per cent of all dogs presently alive.”   
Pariah dogs are the perfect analogue for wolves at the beginning of their domestication, the Coppingers argued. The idea they championed was that self-domestication occurred when humans transitioned from hunting and gathering to farming. This was when our ancestors became sedentary, living in larger groups and producing enough waste to attract wolves, in much the same way that pariah dogs are attracted to settlements today. This shift began around 12,000 years ago in the Middle East.   

“Finds of considerably earlier dogs would naturally disprove the idea,” says Koungoulos. And such finds have now emerged.   
Evolution of the first dogs
Palaeontologists have discovered around two dozen fossil specimens of dogs ranging in age from 35,500 to 13,000 years old across Eurasia, in countries including Spain, France, Belgium, Italy, Switzerland, Germany, Ukraine and Russia. These Palaeolithic dogs have a variety of physical characteristics that distinguish them from wolves. They weigh 31.2 kilograms on average, while Pleistocene wolves weighed around 41.8 kilograms. They also have shorter snouts, a slightly wider palate and shrunken canine teeth. These differences in morphology represent a changing body form that many scientists argue illustrates the budding signs of domestication. In addition, genetic analysis of ancient canid DNA points to south-west Asia and East Asia as the original centres of domestication. Although scientists are still calibrating the exact dates, it now seems clear that dogs emerged over 36,000 years ago in several locations independently. In other words, domestication long predates the transition from hunting and gathering to farming.  
Could these grey wolf pups hold the secret to how domestic dogs evolved?Debbie Steinhausser/Alamy
Some supporters of the self-domestication idea have tried to salvage it by pointing out that palaeolithic hunter-gatherers killed large mammoths and herd animals like bison and deer, so they could have generated enough leftovers to attract and feed meat-hungry carnivores, including wolves. But this argument also has its problems. For one, we know Stone Age people were experts at using all kinds of animal resources and seldom left surplus waste, especially not close to where they were living. Besides, the practices of modern hunter-gatherers suggest that if our ancestors kept excess meat, they would have stored it away from scavengers on platforms or up in trees.   
An even bigger obstacle is research showing that wolves are often seen as dangerous pests. If they get too close and comfortable with humans, they will occasionally prey on young children or other vulnerable members of society. There are documented instances of people killing wolves when they feel threatened by their presence.  
It was evidence like this that turned Koungoulos firmly away from the self-domestication model. “I became pretty convinced that there are deep, consistent, almost structural barriers to self-domestication posed by the innate behaviour of wolves and the typical attitudes of traditional societies towards canids, which are, for the most part, rightly considered dangerous animals,” he says. “[Self-domestication] might make sense for some other domesticated species, but not for large carnivores like this.”  
If not self-domestication, then what?  
The appeal of puppies
One clue pointing to a different origin story comes from a growing understanding of wolf behaviour. Wolves are born blind and don’t develop eyesight until they are about 2 weeks old. During this critical period, they are highly adaptable and able to habituate to humans, which means they can form an attachment to a human caretaker, allowing pups to be safely nurtured and making it less likely they will attack anyone in the future. “If people are willing to put in the work, they can handle practically any type of canid as a companion,” says evolutionary biologist Raymond Pierotti at the University of Kansas, who has raised wolf pups himself. The key is to begin when they are still very young.  
Other clues can be found in the archaeological record. “Palaeolithic dogs are generally, but not always, found in Palaeolithic sites,” says archaeozoologist Mietje Germonpré at the Royal Belgian Institute of Natural Sciences. But they don’t just occur in close association with ancient humans and their settlements; there are also signs that these people had deep connections to dogs and other canids. At a site called ‘Uyun al-Hammam in Jordan, for instance, a fox was buried alongside two humans around 16,000 years ago. The excavators of this grave hypothesised the canine wasn’t a grave good, but a companion, buried together with its owners like part of the family. Numerous sites across Europe, Asia and North America suggest similar relationships.  
The red fox buried alongside two people in a 16,000-year-old grave appears to have been a companion animalMaher et al
Germonpré’s work on Palaeolithic dogs has made her an early and prominent advocate of an alternative model of domestication that is now taking hold among a growing body of academics. It sees wolf pups slowly becoming domesticated after first being adopted by humans as pets. Stone Age people would have taken wolf pups from the wild and nurtured them to adulthood. Then, later, by selectively breeding those with the most desirable traits, domestication would have gradually been achieved. Germonpré calls this the human-initiative model of dog domestication.  
In fact, it isn’t a new idea. Probably the earliest and simplest version of it comes from Francis Galton, Charles Darwin’s cousin. Galton, a Victorian polymath most notorious for founding the field of eugenics, was an extensive traveller and documentarian. This, along with his many connections to the elite of his day, made him aware of the practices of Indigenous populations – including ones who took young wild animals as pets. Galton wrote about Indigenous peoples in North America who captured bear cubs and wolf pups, South Americans who caught and raised birds, and African populations who adopted young buffalo and antelope. This practice of taking young pets, thought Galton, could be the origin of domestication.  

Modern ethnographic reports paint a similar picture. There are accounts from Russia of groups, including the Khanty and Mansi, keeping fox pups as pets and later killing them for their fur. In North America, the Inuit regularly adopted bear cubs into their families, allowing them to play with children and even sleep in their igloos. The Siberian Ket families also adopted young bear cubs, particularly if they had no children. The Ainu of northern Japan and eastern Russia did something similar, adopting and raising young bear cubs to later sacrifice in ritual ceremonies. 
Anthropologists have recorded many instances of hunters taking young carnivores back to camp and these animals being breastfed by women, a practice also mentioned by Galton. We now also know the tendency for cross-species adoption isn’t even confined to humans. Dolphins have been observed to adopt individuals from other species, as have monkeys. This hints that the desire to affiliate with and care for the young of another species has deep evolutionary origins.  
Sacred animals of the Stone Age
However, the modern version of Galton’s hypothesis goes beyond humanity’s fondness for puppies. Germonpré became interested in the earliest manifestations of canid domestication when studying the relationship that Stone Age hunter-gatherers had with cave bears (Ursus spelaeus). Cave bear bones, including skulls, were often burned, painted with ochre and deposited beneath rock slabs, indicating that these fearsome beasts were imbued with symbolic and ritual meaning. This might have given people another reason to want to adopt and raise bear cubs from an early age. “My interest in the pet model as a hypothesis grew from there,” she says, “with the idea that other carnivores, such as wolves, must have had symbolic value for Palaeolithic people, together with other worths and utilities.”  
Archaeological evidence supports this idea. Many excavated prehistoric sites reveal that Stone Age people had a wide variety of uses for wolves. Their teeth were turned into ornaments, perforated skulls hint at ancient rituals and cut marks suggest people ate wolves and fashioned their long bones into tools. But perhaps the most important resource a wolf provided was its pelt.   
Wolf pelts have long been valued as a source of super-warm clothing by the InuitWerner Forman/Universal Images Group/Getty Images
Like other species that live at high latitudes, wolves are adapted to thrive in cold conditions, and this includes sporting super-insulated fur with a mixture of long and short hairs. Historical reports recount hunter-gatherers living in northern latitudes across North America, Europe and Asia using wolf fur to line hoods, collars and other clothing. The Inuit historically captured wolf cubs, raised them and killed them for fur, which was also the fate of the Alaskan wolves adopted by the Iñupiat in Murdoch’s record. Likewise, wolf fur would have been a precious resource for people living during the last glacial maximum between around 26,000 and 19,000 years ago. For tens of thousands of years around this time, people had to endure some of the coldest and harshest climates of the past few million years. It is also the period to which many of the fossils of Palaeolithic dogs date.
Exactly how the process of domestication might have unfolded is unclear. “The specific Asian wolf that was ancestral to today’s dogs is gone forever, so the domestication of the dog can never be recreated under experimental conditions,” says Koungoulos. Nevertheless, he and others think there may have been parallels with a much more modern interaction between humans and wild canids. “One of the best analogues we have is the dingo and its relationship to Australian Aboriginal people – some of the only traditional hunter-gatherer peoples to have, until recently, maintained domestic relations with a wild canid,” he says.   
Living with dingoes
The dingo provides a clear illustration of what happens when small bands of mobile people adopt young wild canines but don’t selectively breed them. Until recently, Aboriginal Australians regularly captured dingo pups and cared for them, but then let them go once they reached adulthood. Dingoes haven’t become domesticated despite thousands of years of this sort of association with people. “But this modern example hints at how a long-term tradition of keeping wild-born canid pups as pets could alter the behaviour of the free-living population, or at least parts of it,” says archaeologist Adam Brumm at Griffith University in Australia.  
 
In a paper co-written with Koungoulos and Germonpré, Brumm speculates that when returned to the wild to breed, dingoes may have taken up residence near Aboriginal camps, forming a sort of human-associated subpopulation apart from other dingoes. Their pups then also tend to be the ones taken from nearby dens and adopted as pets. “Perhaps something similar happened tens of thousands of years ago with the grey wolf, giving rise to the first canids we would recognise as dogs,” says Brumm.  
We may never know for sure, but there are still looming questions that canid researchers hope to answer, including exactly where and when domestication originated. Germonpré wants to address these with further studies of ancient canid DNA. Whatever future studies reveal, however, the old story no longer seems plausible. “The self-domestication model still has a number of supporters and popular books out there,” says Koungoulos, “but my feeling is that, in the face of contrary evidence, they take increasingly fringe positions.”
Pierotti’s assessment is more direct: “Do not let yourself be beguiled by the Coppingers and their way of thought.” 

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A stone tool found on Sulawesi, Indonesia, made by an unknown ancient homininBudianto Hakim et al.
Seven stone tools found on the Indonesian island of Sulawesi are the earliest evidence ever discovered of ancient humans making a sea crossing, dating back up to 1.4 million years.
They may provide clues to how a tiny human species, nicknamed “hobbits”, ended up on the nearby island of Flores.

The first of the artefacts was found embedded in a sandstone outcrop at a site called Calio by Budianto Hakim at the National Research and Innovation Agency in Indonesia in 2019, and a full excavation uncovered six more tools in the same outcrop.
In the same deposit as the stone tools, Hakim and his colleagues found part of the upper jaw, with teeth, of an extinct giant pig known as Celebochoerus, along with a tooth fragment from an unidentifiable species of juvenile elephant.
While the researchers couldn’t directly date the stone tools, they were able to come up with an estimated age of between 1.04 million and 1.48 million years old by analysing the sediments and the fossil pig’s teeth. Until now, evidence of hominins on Sulawesi only stretched back to 194,000 years ago.

At least one of the newly discovered artefacts is a flake that was struck off a larger flake and then had its edges trimmed, says team member Adam Brumm at Griffith University in Brisbane, Australia. While non-human primates like chimpanzees have been known to use stones like a hammer to break open nuts, they don’t carefully work flakes to produce tools.
“This is a very early kind of human intelligence from a species that no longer exists,” says Brumm. “We don’t know what species it was, but this is a human intelligence behind these stone artefacts at the site of Calio.”
The remains of a metre-tall hominin named Homo floresiensis were discovered on Flores in 2003. Archaeological evidence shows that hominins were on that island more than 1 million years ago, but it has been a mystery how an early human species could have made their way there.
Both Flores and Sulawesi had large expanses of sea separating them from mainland South-East Asia, even during the periods of lowest sea levels. Brumm says the distances between the mainland and Sulawesi were too great to swim and it is almost certain that these early hominins weren’t capable of building ocean-going vessels.
“It may have been some sort of freak geological event, like a tsunami, for example, washing some hominins out to sea clinging to floating trees or vegetation mats of some kind, and then winding up on these islands in large enough numbers to give rise to these isolated populations,” he says.

Martin Porr at the University of Western Australia says Homo erectus was the most likely candidate to have made the sea crossings, as this species was in South-East Asia at this time and made tools similar to those found in Sulawesi.
He says while the new work is consistent with this hypothesis, it also raises many new questions, especially whether the capabilities of these early hominins need to be revised.
The late archaeologist Mike Morwood, who led the team that identified Homo floresiensis, was the first to suggest that Sulawesi was an important place to search for potential ancestors of the hobbits, says Kira Westaway at Macquarie University in Sydney, Australia. This is due to the path of the Indonesian throughflow, a strong current that flows from Sulawesi to Flores.
“But I think that even Mike would be pleasantly surprised by the antiquity of the stone tools found at this site,” she says. “It could be argued that seven tools is not a large enough assemblage to support large claims, but it certainly represents an early hominin presence.”

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