In Spring, poppies line the well-trodden footpath that leads the way to the Shanidar Cave. Scattered trees cling determinedly to the rocky hillside. Grasses smother the foothills. In the distance, looking down on those bold enough to make the climb is the gaping hollow of the cave’s enormous, triangular mouth, carving a shadow deep into the mountainside. It’s here, 60 years ago, that the bodies of seven adults and two children were unearthed. They were buried deep in the gloomy abyss and by the time they were found, tens of thousands of years after they fell, they were nothing more than bone. But by studying their remains, researchers have managed to piece together a remarkable story from long ago, one with all the hallmarks of a Hollywood blockbuster. It has violence and hardship, compassion and hope. It’s a tale of immense courage and of survival against all the odds. But most of all it’s a story that challenges our perceptions of what it means to be human.
The Shanidar Cave lies in the foothills of the Zagros Mountains in northern Iraq, and the bodies, painstakingly exhumed by US archaeologist Ralph Solecki and his team, belonged to an extinct species of ancient humans – the Neanderthals. This particular story concentrates on the first body to be found, an adult man whom they dubbed ‘Shanidar #1’, or ‘Nandy’ for short. His is one of the most complete Neanderthal skeletons ever found, but when they realised the state he was in, they baulked. The left side of his skull, which should have been smooth and rounded, was badly bashed in. His right arm, or what was left of it, was broken, withered and ended in a stump near the elbow. He had a broken bone in his foot, and arthritis in his lower right leg.
At first glance, the autopsy paints a picture of a lead character seriously down on his luck. The blow to his skull, maybe caused by a falling rock, would have left him struggling to see and paralysed down one side. The bottom of his right arm had been amputated, either deliberately or in some freak accident. His arthritis would have been a constant source of pain, and walking would have been difficult.
That we can tell so much about a life from bones alone is impressive, but there was more in store. The fact that Nandy’s body had seen better days comes as little surprise – life in the Ice Age was, after all, no picnic. What’s remarkable is that his broken bones show signs of having healed. Nandy recovered from his various injuries and went on to live for some time despite the difficulties with which they left him. Blind, paralysed and in constant pain, Nandy somehow managed to cope with his disabilities, eventually dying at a ripe old Neanderthal age of around 40. But there’s no way he could have done this alone. After his injuries, Nandy would have been unable to hunt, run or defend himself. In a time of sabre-toothed cats and cave bears, this would have made him incredibly vulnerable. He would have needed help. Somebody (or somebodies) must have brought him food, kept him safe and helped to keep him going. In a time of need, Nandy had friends. Solecki concluded that Nandy was accepted and supported by his people up to the day he died.
After the brutality and suffering, the story has a happy ending. Nandy wasn’t left to die. It’s a little known fact that Neanderthals cared for their disabled. They looked after the elderly and nurtured the ill. The final credits go to the supporting cast of carers who helped our hero through his final years.
Meet the Family
Neanderthals are the undisputed King of the Cavemen. An extinct species of ancient human, they flourished in Europe and parts of Asia and the Middle East towards the end of the Pleistocene. Stocky, strong and ripped with muscles, they were similar to the East European shot-putters of today, but even hairier. In a time before razors and depilatory formulae, these prehistoric people hid their chinless faces under unkempt beards and their jutting brows beneath dishevelled dreadlocks. Sixty thousand years ago we met them in Asia, and after that in Europe. Then, around 40,000 years ago, Neanderthals disappeared (no one’s exactly sure why), while us ‘modern humans’ trickled across the continents and slowly took over the world. Extinct they may be, but Neanderthals remain our closest human relatives. To bring back a Neanderthal would be to meet an old member of our family, to step back in time – and take an unprecedented sneaky peek into the story of human evolution.
It would certainly be intriguing to meet a Neanderthal face to face, to find out firsthand the similarities and differences between us. If he or she were clean-shaven and smartly dressed, would we even notice them if we sat next to them on a park bench? If we did, would the conversation flow? Could we become friends? Go out clubbing? Could a Neanderthal hold down a job, a marriage or a modern meal? How ‘human’ would he or she be? Whether or not we ‘should’ do it is a question I’ll return to later, but for now, as thought experiments go, you have to admit it’s a good one.
We’ve been fascinated by Neanderthals ever since they were first discovered, in a limestone quarry in Germany’s Neander Valley, way back in 1856. The Victorians, who believed that God had created man in his image just a few thousand years before, struggled to accept that the primitive-looking skeleton, with its protruding brow ridges and thick bowed legs, could ever be human. Instead it was dubbed some kind of primeval ‘missing link’, a stupid ape-like creature with no redeeming features. Its barrel-shaped chest could never have squeezed into a whalebone corset. Ugly and unfamiliar, it could never had played croquet or taken tea. Neanderthals were, the Victorians concluded, savage and subhuman.
It was the beginning of a smear campaign that has plagued the Neanderthals ever since, not to mention one of the longest and most heated debates in modern science – how sophisticated or otherwise were these people? Even today, after archaeologists have pored over the remains of hundreds of different individuals and found copious evidence to the contrary, Neanderthals are still perceived as club-wielding, loin cloth-wearing savages. In popular culture, they’re often displayed as unkempt cavemen who dragged their knuckles on the floor and communicated like modern-day teenagers – with the same inarticulate grunts and gestures. Even in conversation, the term is used in the pejorative. To call someone a Neanderthal is to call them a hirsute, stupid thug. They are the perennial butt of evolutionary jokes – a Neanderthal walks into a bar and says … nothing. He can’t even talk. Worst of all, they’re not even here to defend themselves. Talk about kicking a man when he’s extinct.
The fact is that from fossil remains and other lines of evidence we know more about this particular extinct hominin species than any other, and the Neanderthal stereotype is unjust, unfounded and unnecessary. Nandy’s story shows us that Neanderthals were capable of compassion and camaraderie. An ancient human that cared for its sick, its disabled and its elderly is not so different from us. Far from savage, these people must have had deep social bonds, just as we do today. They looked out for one another, and cared for their comrades when in need. Perhaps they would fit in with us after all.
But could we ever bring back the King of the Cavemen? I should perhaps stress at this point that no one, to my knowledge, is seriously planning to resurrect a Neanderthal. But while researching this book, I have spoken to various highly qualified, well-respected researchers, all of whom tell me that making a Neanderthal is entirely possible – not with some as-yet undetermined technology, but with the know-how, kit and caboodle that we have today.
If nothing else, de-extincting Neanderthals might go some way to resolving the smear campaign against them, providing Nandy and his kin with some much needed positive spin. It would certainly help to inform the ‘what were they like?’ debate. While bone can survive in the fossil record, soft tissues and organs more often than not rot away. Resurrecting a Neanderthal would quite literally put flesh on the bones. We’d find out not just what they look like, but how they behave and what they can do. A project of this kind could have even grander goals. Harvard biologist George Church, of whom much more later, argues in his book Regenesis that resurrecting a fellow human species would do more than simply satisfy academic curiosity. It might, he argues, help us think about ourselves differently, and lend insights into other forms of human intelligence and different ways of thinking. There could be health benefits. What if Neanderthals turned out to be naturally resistant to, say, the HIV virus, or to the bacterium that causes tuberculosis? Insights gleaned from their biology could be used to help develop new therapies for our own species. By studying their embryonic development, we could learn more about the processes that guide our own. And if a Neanderthal ever did walk into a bar, I’d like to be there to buy them a drink, on the rocks, of course, and hear what they really have got to say.
A Terrible Smell
If cleanliness is next to Godliness, then Svante Pääbo is right up there with the cherubs on the clouds. The Swedish biologist has founded his career on a level of cleanliness bordering on paranoia. Pääbo is Director at the Max Planck Institute for Evolutionary Anthropology, a curvaceous, custom-built research facility in Leipzig, Germany, where he goes to extreme lengths to recover DNA from fossils. He’s fanatical about keeping his samples, researchers and laboratory absolutely spotless in order to minimise the chances of contaminants tainting his experiments. As a result, he has changed the way we think about human history. He has prised DNA from a finger bone found in a Siberian cave to reveal the existence of a previously unknown species of human called the Denisovans. And he has sequenced the entire genome of the Neanderthal, revealing an unexpectedly spicy secret from our dim and distant past. Through his scientific rigour and attention to detail, Pääbo has arguably done more than anyone else to advance the field of ancient DNA.
Pääbo’s career in ancient DNA took off after he cooked up a very unappetising piece of liver. It was the late seventies and Pääbo, who was working in virology at the time, had heard about some new techniques that enabled researchers to extract and sequence DNA. Obsessed with Ancient Egypt since his childhood, Pääbo found himself wondering if it might be possible to recover DNA from Egyptian mummies. At the time, the received wisdom was that the task was impossible, that the bandaged bodies would have been hanging around for far too long to have any DNA left in them. But Pääbo reasoned that if the enzymes that break down DNA need water to work then the molecule might still persist in ancient tissues that had been desiccated or mummified. He devised an experiment to test his idea, but because he was meant to be working on other things he decided to keep it a secret from his boss.
With no access to any Egyptian mummies, Pääbo had to make his own mummified tissue. So he went to his local supermarket, bought some cow’s liver, then bunged it in the lab oven on a low heat and left it to fester. Twenty-four hours later the smell of putrefied flesh filled the room and his clandestine bake-off was in danger of being busted. But the air soon cleared and all that was left a few days later was a hunk of meat so dry that a Michelin inspector would have been more likely to check it for tread than award it a star. The meat may have been well past its sell-by date, but much to Pääbo’s delight, its DNA was not. Desiccation had not destroyed all of the cells’ genetic material. Small fragments could still be found.
If DNA could be found in over-cooked dinner, perhaps, he thought, it really could be found in the desiccated bodies of pharaohs. He was granted access to 20 mummies at the State Museum in Germany’s East Berlin, but when he took samples and tested them for DNA, they all drew a blank … apart from one. Pääbo hit the jackpot with a 2,400-year-old mummy of a child. It was time, he decided, to come clean about his secret experiments. Pääbo told his supervisor and, with his full blessing, went on to publish his findings in the journal Nature, bagging the front cover with a mock-up of a mummy tastefully draped in DNA.
‘The Nature paper created a real buzz,’ says ancient DNA researcher Tom Gilbert from the University of Copenhagen in Denmark. ‘People were really excited.’ With Pääbo’s finding, the prospect of DNA from the deep past was no longer a pipe dream. Suddenly, everyone wanted in on the action. There followed what has since become known as the Wild West years of ancient DNA research, where it seemed anyone with a passing fancy in ancient DNA chanced their arm at extracting it. Claims of ‘antediluvian DNA’ hit the headlines (see Chapter 1). Researchers claimed to have found DNA from fossil plants, insects and dinosaurs, but it all came crashing down when researchers realised that modern DNA, most likely from the people who had handled the samples, had tainted the results. Extreme measures were required. If Pääbo were to trust his results, he had to be sure that the DNA he was finding was genuinely ancient and not some modern contaminant. So it’s here that his penchant for the pristine began in earnest.
At the University of Munich, he built the world’s first ‘clean room’ for ancient DNA, a small windowless cell that he scrubbed with bleach and kept squeaky clean. Anyone working there had to wear CSI-style overalls, gloves, face masks and hairnets in order to make sure that none of their own DNA contaminated the samples they were studying. To be on the safe side, Pääbo decided to hone his techniques on extinct animals, rather than ancient humans, reasoning that even if he did find human DNA in a fossil, it would be impossible to tell if it came from an ancient person or a member of his own lab. So when he successfully isolated snippets of DNA from a 25,000-year-old horse, and then from a 50,000-year-old mammoth, he was pretty certain that the DNA he’d found was genuine. There were, after all, no Ice Age horses or mammoths roaming around the lab.
It was only then that he turned his attention to Neanderthals. They seemed like a good choice to study for many reasons. For a start, they are our closest evolutionary relatives. They lived recently enough that their bones could still contain DNA, yet were still reassuringly ancient. Studying the genetic differences between Neanderthals and modern humans would, he hoped, enable researchers to identify the key changes that set our earliest ancestors aside not just from Neanderthals, but from everyone and everything else on the planet. It could help explain why Neanderthals produced rudimentary tools and hunted mammoths, while we acquired the capacity to text and dial a pizza. It could help clarify how Neanderthals were capable of culture, art and abstract thought, yet never created social media or the Sistine Chapel. The differences could help explain why Neanderthals disappeared while we flourished. From Neanderthal DNA, Pääbo hoped to glimpse the biological origins of being human.
Pääbo was offered access to a German national treasure, the first ever Neanderthal to be found, which was kept at the Bonn Museum. Using a tiny sample from the fossil’s upper right arm, Pääbo was able to work his magic again. Sixteen years after he had extracted DNA from his shop-bought liver, he became the first scientist to isolate DNA from an ancient human.
Like all of the reputable ancient DNA studies that had gone before, Pääbo chose to extract DNA not from the cell’s nucleus but from its other hiding place, tiny energy-producing structures called mitochondria, where DNA is more plentiful. A single cell can have thousands of mitochondria, and a single mitochondrion can have hundreds of copies of DNA. Compare that with the two DNA copies found inside the one nucleus of a regular cell, and mitochondrial DNA seems like a comparatively low-hanging fruit. So it was mitochondrial rather than nuclear DNA that Pääbo had extracted from the Neander Valley specimen. It was impressive, but if researchers were really to unravel the genetic secrets of the Neanderthal, they would need more than just mitochondrial DNA. Genomes, we know, are made from mitochondrial DNA and nuclear DNA, but it’s the nuclear DNA that makes up 99.9995 per cent of the total sequence. So if Pääbo were to decode the Neanderthal’s genome in its entirety, he would need to be able to retrieve DNA from Neanderthal cell nuclei.
But at this point in time, no one knew if that was possible. In the end, it took some remarkable poo to settle the matter once and for all.
Top of the Plops
In the late nineties, Hendrik Poinar, a Californian geneticist working in Pääbo’s lab, was studying ‘molecular coproscopy’, or, to give it its proper name, ‘the study of fossil poo’. Top of the plops for Poinar were the ancient faeces of the extinct Shasta ground sloth (Nothrotheriops shastensis), a bear-sized vegetarian from the last Ice Age. Like so many of my previous boyfriends, it had long, coarse hair, prehensile lips and walked on its knuckles. Unlike my exes, however, it ate a lot of plants and left a lot of droppings in the dry caves of what is now the southwestern United States. At one site, the Rampart Cave in the Grand Canyon, Arizona, the floor is literally wall to wall dung balls. Now faeces may not be a living creature, but they still contain DNA, and over millennia on the cave floor the sloths’ dung had become fossilised.
Poinar studied the chemical composition of the poo and found that it bore the tell-tale signs of a reaction more frequently found in the kitchen. The Maillard reaction, as it is known, occurs when common sugars are warmed for a long time. Sugar molecules form chemical cross-links with proteins and DNA, causing large, tangled complexes that give browned foods, such as bread and steak, their flavour. Poinar’s experiments suggested that many millennia ago, as the warm dung lay slowly fermenting on the cave floor, the same reaction had occurred. Ancient DNA had become tangled up with other molecules, meaning that the method used to detect and amplify it – the Polymerase Chain Reaction (PCR) – simply wouldn’t work. But the Maillard reaction can be reversed. When a particular chemical is added to baked bread, it breaks the tangles apart and returns the loaf to dough. When Poinar added the same chemical to extracts of his coprolites he found, to his delight, that the fossil’s inner DNA could be liberated. He found not just mitochondrial DNA but nuclear DNA, too. The experiments suggested that sometimes nuclear DNA could survive inside and be extracted from ancient fossils. And if nuclear DNA could be retrieved from Ice Age poo, perhaps it could also be retrieved from other Ice Age denizens, including Neanderthals.
Ultimately, it would take a few years and some serious new kit to turn this dream into reality. One big problem was the method used to retrieve DNA from the ancient samples. To that point, researchers had used PCR, which amplifies tiny fragments of DNA into larger amounts so that it can be studied. But the procedure is notoriously prone to contamination. If there is even the tiniest bit of modern DNA in a sample – from a skin cell, say, belonging to the researcher who handled the samples, or from a bit of dust in the laboratory – then very often that is the DNA that gets amplified. Modern, contaminating DNA can swamp a sample and wreck it as a result. A tedious and untrustworthy process, Pääbo realised that new techniques were needed.
They arrived in the noughties in the guise of ‘Next Generation Sequencing (NGS)’. It sounded very Star Trek, and just like the TV show quickly built a loyal fanbase of geeky types who preferred it to the original. It was sequencing, Jim, but not as we know it. Where PCR focused on just one specific DNA fragment at a time, NGS could read, or ‘sequence’, all of the many thousands of tiny DNA fragments in a sample in one go. It did away with the troublesome PCR step, so researchers didn’t have to worry about modern contamination drowning out the DNA they were interested in.
Pääbo was so impressed, he bought his own NGS machine, and after sequencing a respectable million base pairs of Neanderthal DNA, announced to the world that next he would sequence the entire nuclear genome. But there was another problem. Modern contamination might not have been an issue anymore, but ancient contamination was. Pääbo realised that the Neanderthal samples he cared about so deeply tended to contain around 3 per cent Neanderthal DNA and 97 per cent DNA from bacteria that had, at some point, feasted on the bone. With NGS sequencing all the DNA in a sample, it meant that most of the data generated would be of no interest at all.
In the end, Pääbo had to add two new steps to his methods: one to physically remove the unwanted ancient DNA, and the other to amplify the little Neanderthal DNA there was. With his new improved protocol the Neanderthal genome was well on its way, but Pääbo and his team faced one last challenge. Where modern DNA is long and stringy, ancient DNA is broken and bitty. Most fragments prised from millennia-old fossils are just tens of nucleotides long. How, then, to reassemble these tiny pieces into a genome three billion letters long?
Imagine the largest, most complicated jigsaw that you’ve ever done. Then imagine that many of the pieces are damaged, and many others are missing. Annoyingly, there are also extra bits that don’t seem to fit anywhere, and random additional copies of pieces that do. Reassembling the Neanderthal genome is a bit like doing that puzzle. According to Amazon.com, the world’s most difficult jigsaw puzzle is ‘The Sweet Shop’, a double-sider featuring Smarties. The Neanderthal genome, in contrast, is a three-dimensional puzzle featuring nucleotides. And where ‘The Sweet Shop’ has 529 pieces, the Neanderthal genome has hundreds of thousands.
Just as the Amazon puzzle would be tricky to fit together without the picture on the box, so too Pääbo and his team needed some sort of reference to help them arrange the bits of DNA into the right order. So they used ‘reference genomes’. They took the sequences of two modern genomes that had already been sequenced – the human and the chimp – and used them as comparisons. Armed with this information, a clever computer algorithm was then able to piece the waif-like scraps of ancient DNA back together again. In 2009, Pääbo announced to the world that he had finally sequenced the Neanderthal genome.
The sequence was what geneticists call a ‘draft’ genome, meaning that although it was the best they could do with the technology they had, it wasn’t quite complete. It may seem odd, but in the world of genomes it’s completely acceptable to publish draft versions. A working draft of the human genome was published in 2000, three years ahead of the finished article. But I know of no other research areas where the practice is embraced. The team at CERN didn’t publish half the Higgs Boson, nor did mankind celebrate when Apollo 11 got halfway to the moon. But credit where it’s due. Pääbo had dedicated his career to overcoming the technical hurdles that had plagued the field of ancient DNA since its inception, and in the process had achieved the seemingly impossible. It was the first genome of an extinct human ever to be decoded.
Make Me a Caveman
In the months following the genome’s publication, several things happened. Pääbo’s team continued to sequence Neanderthal DNA with a view to upgrading their genome from ‘draft’ to ‘complete’, while other researchers got justly excited and started to use the freely available sequence data. Pääbo started to receive letters from men who thought they were Neanderthals, and from women who thought their husbands were. Meanwhile, the New York Times reported that a Neanderthal could be brought to life with existing technology for around $30 million.
This claim was attributed to geneticist George Church, and if anyone should know what genetics is capable of, it’s him. One of the founders of the human genome project, he helped develop the modern sequencing methods that made reading the Neanderthal genome possible in the first place. Today he continues to push the boundaries of what genetics can achieve. Members of his lab at Harvard Medical School are tinkering with DNA in order to do all sorts of things, including helping to understand human disease, devising new therapies and bringing extinct species back to life. He’s currently working on a plan to resurrect the woolly mammoth (see Chapter 3).
‘Making a Neanderthal is technically possible,’ he tells me when I speak to him on the phone one summer evening, ‘if anyone really wanted to do it.’ Three years after Pääbo published the draft Neanderthal genome, the complete version was made available. This time, the researchers had dotted all the i’s and crossed all the t’s1 . In fact, every position in the genome had been read an average of 50 times over, making it of similar quality to the human genome.
But it’s one thing to reconstruct the Neanderthal genome inside a computer, and quite another to somehow magic it into life. As it exists today, the Neanderthal genome is information stored in digital form. If someone was to print out all of the letters in one single long line, it would stretch for 3,100 miles, the distance from London, England to Boston, Massachusetts. If someone were to publish it in book form, it would fill 5,000 paperbacks and have as much punctuation and plot as chick lit. If you read one letter per second, you’d lose 95 years of your life. A would-be Neanderthal-maker would have to turn this lengthy digital recipe into biological information in the form of actual DNA inside an actual cell.
When the letters of the Neanderthal and the human genome are lined up next to each other inside a computer, it’s obvious to see that the vast majority of the letters are the same. Modern humans and Neanderthals, we now realise, share well over 99 per cent of their DNA. So there’s no point making a Neanderthal genome from scratch, even if such a thing were possible. Instead, the best option would be to start with a human genome inside a human cell and then alter it to become Neanderthal-like.
When I worked in the lab in the early nineties, altering or editing DNA was an arduous labour of love in which only one genetic change could be tackled at a time. But things are different now. Technology has progressed and gene editing is now faster, cheaper and more accurate than ever before. To Neanderthalise a human genome, around 10 million changes would need to be made – a tall order but not impossible. It could be done by a process called Multiplex Automated Genome Engineering (MAGE), which can make hundreds of changes to a genome all at the same time, effectively accelerating evolution and earning the technique its alternative moniker of the ‘the evolution machine’. It’s the brainchild of none other than George Church, the man who once told de-extinction champion Stewart Brand, ‘I don’t just read DNA, I write DNA.’ Church envisages that the process could have myriad benefits, such as making bacteria that churn out biofuels. But he also tells me that although it’s not something he plans to do himself, it could also be used to Neanderthal-ise a human cell. The technique would involve breaking up the human genome into thousands of smaller, more manageable chunks, ferrying them into specially adapted bacteria where the desired changes would be made, and then reassembling the modified DNA into 23 pairs of chromosomes inside human cells. The DNA blueprint inside those cells could then be used for cloning. ‘Neanderthal’ DNA could be injected into a human egg that had had its own nuclear genome removed, then the developing embryo transferred into the womb of a human surrogate who would hopefully be able to carry the embryo to term.
So leaving aside, for one moment, the issue of whether or not this experiment should be done, let’s think about what the outcome would be. It’ll lend weight to the ‘should we?’ argument that follows. Let’s, for the sake of expediency, presume that the baby is male (but it could equally be female) and let’s, for the sake of argument, call him Hermann, after the nineteenth-century German anatomist Hermann Schaaffhausen, who studied the original Neander Valley Neanderthal.
Just like all of us, Hermann would be a product of nature and of nurture, influenced by his genetic legacy and by the environment in which he grew. Certain characteristics, such as height, hair and eye colour, would be strongly determined by genetics, while others, such as personality and preferences, would be more influenced by upbringing. An infant Neanderthal born today would be subject to the same yin and yang of interacting influences that any child is, making predictions at best speculative, at worst hopelessly inaccurate. But bear with me. Let’s examine the relevant information, mined both from the fossil record and the Neanderthal genome, to suggest how Hermann might turn out.
Let’s start with the birth. Studies of Neanderthal skulls reveal that their brains were around 10 per cent bigger than our own, enough to put even the most experienced of human mothers off a natural birth. As the first Neanderthal born in 40,000 years, midwives and medics would not want to leave anything to chance, so baby Hermann would very likely be delivered by C-section. To all intents and purposes, the freshly delivered baby would look pretty much like any other human newborn – like a grumpy old man deprived of cake. Chances are that Hermann would be pasty faced, maybe freckled. Peoples that have lived in higher latitudes for extended periods have adapted to those conditions by losing the darker skin pigmentation that is common closer to the equator. And when ancient DNA expert Carles Lalueza-Fox from the University of Barcelona, Spain, probed the sequence of a gene related to skin and hair colour, he found that some Neanderthals carried a version likely to result in pale complexions and fiery locks. Hermann might well be a redhead.
But being ginger and/or Neanderthal is no reason to deny any child its basic human rights. They may have been a different species of human to us, but Neanderthals were still human. With this in mind, Hermann would deserve the same upbringing as any human child. We know from fossil finds that Ice Age Neanderthals lived in small, tight-knit social groups where they shared their daily lives and looked after one another – just think of Nandy. Ensconced in the security of a loving, modern family, Hermann would probably thrive. ‘A Neanderthal born today would be well suited to the nuclear family,’ says anthropologist Thomas Wynn from the University of Colorado, who considers this scenario carefully in his book How to Think Like a Neanderthal. ‘He would probably be a very loving child.’ He would be happiest at home with his immediate family, and would be empathetic and supportive towards his siblings. Outside of the family, however, he might be quite a shy child, mistrustful of those he didn’t know. In order to survive, Neanderthals would have had to treat strangers – Neanderthals from neighbouring territories or modern humans migrating from Africa – with suspicion and sometimes hostility. So he might struggle to make friends outside of the family group, and find nursery daunting. ‘He would almost certainly not want to be left,’ says Wynn, ‘to the extent that home schooling might be the best option.’
On weaning, an adoptive parent would be wise to watch the dairy and go gluten free; this baby’s genome evolved several hundred thousand years before the agricultural revolution, so Hermann would have difficulty stomaching a modern diet heavy in grains and dairy. Despite their image as mammoth-hunting, bison-stabbing carnivores, there is now plenty of evidence to suggest that Neanderthals ate a rich, varied diet that was both organic and locally sourced. In northern Europe they ate a lot of meat, in southern Europe a lot of seafood, including seals, dolphins and shellfish. Analyses of Neanderthal poop and teeth reveal they also ate vegetables that they probably roasted on open fires. Carles Lalueza-Fox has shown that Neaderthals also shared with us a gene that gave them the ability to taste bitter compounds in certain foods. Hermann would do well on a varied modern human diet light in dairy and wheat, but he’d be just as likely to catapult his broccoli across the kitchen as any other child.
Initially, it’s probable that family and friends would notice little difference socially, cognitively or physically between Hermann and any other Homo sapiens siblings. The classic Neanderthal features – the sticky-out brow ridges, the odd-shaped head and stocky frame – would lie within the normal range of human variability. Modern humans, after all, come in all shapes and sizes, and just as some of us look more Neanderthal-like than others, so too a de-extincted Neanderthal could look more or less human. Hermann might not have much of an obvious chin, he might well be stockier and stronger than the average infant, but he’d look no more out of place in a crowd than any other child.
Let’s Talk Neanderthal
As he turned into a toddler, Hermann would start to learn to talk. A constant source of argument among anthropologists, there are those who think Neanderthals incapable of language and those who believe that language evolved around half a million years ago, in the presumed common ancestor of Neanderthals and modern humans, the tool-using, fire-making Homo heidelbergensis. If these very early humans had language, which is what Dan Dediu, from the Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands, and others have argued, then Neanderthals must have had it, too.
Certainly the requisite biology appears to be there. Their face and throat was put together in such a way that Neanderthals were, in theory at least, capable of speech. Just like us, they had a tiny horseshoe-shaped bone at the back of their throat. In modern humans, the so-called hyoid bone supports the tongue and helps control speech. The Neanderthal hyoid not only looked like ours, it seems to have worked like ours, too.
Aspects of their brain anatomy were also similar to our own. Although brains are generally too mushy to survive fossilisation, the skulls that contain them are not. By studying the inside of the skull, researchers can gauge the overall size and proportions of the brain it once housed. One region, known as Broca’s area, is of particular interest. Located in the lower left frontal lobe, Broca’s area controls the production of speech. Damage to the area, from a tumour or stroke, for example, can rob a person of their ability to talk. Taking the overall size of the brain into account, our Broca’s region is bigger than that of our mute non-human primate relatives, and the brains of Neanderthals were, it seems, similarly proportioned – evidence perhaps that Neanderthal brains were capable of generating speech.
Then in 2007, Svante Pääbo and colleagues showed that Neanderthals carried a human-like version of a gene related to speech and language: the FOXP2 gene. People with an abnormal version of this gene have speech impediments, learning difficulties and struggle with certain kinds of grammar, but Neanderthals have the normal sort – evidence again for the ability to talk?
Collectively, the findings are an enticing smorgasbord of titbits, but they’re not a smoking gun for witty repartee. The physical articulation of speech involves far more than the hyoid bone. In non-human primates, and perhaps in Neanderthals, Broca’s area is used for non-linguistic tasks like reaching with the hands. And FOXP2 is not a gene ‘for language’, it’s a gene related to language. It also does other things. On sober reflection, the evidence is circumstantial and, some would say, tenuous. Language, unfortunately, does not preserve directly in rocks nor even in the genome, but if one takes a step back and looks at the cumulative picture from 150 years of Neanderthal research, the picture that emerges is of a people that had to be able to communicate with a level of sophistication way beyond inarticulate grunts and gesticulation.
These were people who made some complicated bits of kit: distinctive curved flint knives intentionally dulled on one side so they could be handheld; foot-long ivory spear points with incisions to help them fit onto wooden handles; and ‘lissoirs’, polished tools hewn from deer ribs, used to smooth hides and create softer, more water-resistant leather. That they could learn to make these things by observation alone is unlikely. More probable is that they received some verbal instruction. These were people who were expert hunters. They relied on a detailed knowledge of the local landscape and of hunting tactics to locate and bring down their prey. It takes more than one man to fell a mammoth, so it’s likely that Neanderthals communicated with one another to discuss hunting strategies and coordinate their kills, and used language to pass their knowledge on through generations. That they made ornaments from teeth, bone and shell, and prepared pigment and painted their bodies with it, implies they were capable of symbolic thought – a prerequisite, some argue, for language where abstract words or symbols acquire reliable meaning.
Multiple lines of evidence, circumstantial though they may be, cumulatively suggest that Neanderthals were capable of speech. ‘I may have no direct proof, but I have a strong suspicion that Neanderthals had language,’ says Thomas Wynn. ‘They’re too closely related to us not to have some sort of language.’ With the same genome instructing development, and the right environmental cues, a modern-day Neanderthal should be similarly able to acquire and generate language.
As Hermann grew into a toddler, he’d start to babble and then to talk. His first word could be ‘mama’, it could be ‘mammoth’, but in the early days at least, there’d be little difference between Hermann’s verbal skills and those of any other human infant. It’s only a little later when kids start constructing and understanding more complex sentences – ‘I know you want to throw the broccoli at your sister but you know that I don’t want you to’ – that Hermann might start to lag. Such complicated sentences could prove hard to understand and hard to construct. Ironically, given it’s the country where the first Neanderthal was found, the German language, with its verb-dense sentence endings, could prove particularly difficult for Hermann to master. But just like his appearance, Hermann’s ability to master language would still fall within the normal range of modern human variation. There are, after all, plenty of us who prefer to avoid over-complicated, unnecessary syntax and keep things simple.
Another subtle difference could be in the way that Hermann sounds. Neanderthal vocal tracts were shaped slightly differently to our own, prompting speculation that their voices may have sounded different. In 2008, anthropologist Robert McCarthy from the Florida Atlantic University in Boca Raton simulated Neanderthal speech based on reconstructions from fossils. It was the first time anyone had heard a Neanderthal voice – albeit one generated by a synthesiser – for 40,000 years. He found that the ancient humans were unable to generate certain sounds, known as quantal vowels, which are present in modern speech and help people with different-size vocal tracts to understand each other. Neanderthals, McCarthy concluded, would have struggled to produce the subtleties of the sound ‘ee’. So Hermann’s adoptive parents might be unsure whether the child wanted to ‘heat’ or ‘hit’ his siblings.
Intelligence-wise, Hermann would probably be no Einstein, but neither would he be the halfwit his Neanderthal forebears were erroneously purported to be. On the negative side, Neanderthal technology changed little over hundreds of thousands of years, suggesting that Neanderthals weren’t natural innovators. Fifty thousand years ago, Neanderthals in Europe were still killing large animals the way they always had: up close and personal with big, stabby spears, while the new kids on the block, modern humans from Africa, had invented spear throwers so they could kill more safely, from a distance. It’s evidence, some say, that Neanderthals were lacking in working memory, the ability to actively hold and manipulate multiple pieces of fleeting information in the brain. And as working memory correlates with intelligence it is, by extension, an indication that Neanderthals were not the cleverest. But on the plus side, Neanderthals did survive for hundreds of thousands of years despite a constant battering from some of the most erratic and extreme weather the world has ever seen, making them resourceful and adaptive. They might not have passed exams or mastered algebra, but that doesn’t make them stupid. They may not have been clever in the same way we are now, but to deny them the same potential would be, in my view, a mistake.
So what have we learned about Hermann? The picture emerging is of a shy, socially awkward child that looks and sounds a bit different, but that is loving and happy at home and more or less hitting his developmental milestones within the normal timescale. In short, Hermann would be pretty much like millions of other kids alive today.
His fondness for family life would continue into adulthood. If Nandy is anything to go by, he’d probably stand by his parents and look after them in their old age. He’d probably want children of his own and one day he’d meet a girl and settle down. He’d be a pragmatic individual who’d put his family first and work hard to provide for them. A man of few words with a tendency for straight talking, he’d excel in a job that played to his pragmatic, no-nonsense nature. Thomas Wynn suggests several careers that would fit. A natural craftsman, capable of reiterating complex learned procedures, he’d make an excellent blacksmith or machinist. He’d also be good at fixing up cars or repairing engines, but he wouldn’t be restricted to engineering. Neanderthals had a deep understanding of the natural world, carried detailed mental maps of their environment, and planned and executed audacious hunting trips. So Hermann might make a skilled commercial fisherman or excel in the military. He might not be able to explain the intricacies of GPS or military radar, but he’d certainly be able to use them. He might not come up with innovative problem-solving strategies, but he could certainly implement learned manoeuvres, and he’d be a determined and fanatically loyal co-worker.
Ice Age Neanderthals endured extreme hardship, were frequently injured and learned to tolerate pain, so Hermann would be unlikely to succumb to that most dreadful of modern scourges, ‘man flu’. He’d also, given the story of Nandy, be kindly and sympathetic towards his partner if she ever became ill, say, the morning after a night out with her friends. He’d still struggle with strangers, but once he determined the aliens were friendly, he would be warm and generous, perhaps overly so. Hermann could be naïve and gullible and easily conned. He’d probably be no good with money.
The picture we have is of a man that talks little, moans less and nurses a girl with a hangover. He loves his family and steadfastly brings home the bacon but relies on his wife to manage the purse strings. If you’re a little like me, Hermann’s starting to look like a bit of a catch. The only possible drawback to marrying a Neanderthal, speculates Thomas Wynn, is that he might want to be with you physically 24:7. ‘It seems “his and her spaces” were not a Neanderthal forté,’ says Wynn. If you like needy men, however, he could be the one for you.
In the Ice Age, their arduous lifestyles left adult Neanderthals struggling with arthritis and they rarely lived beyond 40. But there’s no reason to think, with the added comforts of modern life, that this Neanderthal wouldn’t live arthritis-free, well into his eighties or longer. Hermann and his wife could grow old together.
Perhaps We Could, But Should We?
So there it is – the story of a Neanderthal born into a twenty-first-century world. It starts with ancient DNA, harvested from the remains of genuine Neanderthals long dead. It then sees scientists use this Ice Age recipe to ‘Neanderthal-ise’ a modern human genome, and then use cloning to create a living, breathing Neanderthal baby that would live and die in our busy, chaotic modern world. It would be an incredible feat.
As it stands today, there are no laws to prohibit the cloning of a Neanderthal. ‘It’s not illegal to do what you’re talking about,’ says bioethicist Arthur Caplan from the NYU Langone Medical Center in New York. Around 10 years ago, Caplan sat on the advisory committee to the United Nations on Human Cloning, a group that sought to reach an internationally binding agreement on reproductive and therapeutic cloning. In the end, countries reached their own legislative solutions, but back then ancient human DNA was so far off the radar as to make cloning a Neanderthal unheard of. ‘No one was thinking about anything other than Homo sapiens,’ says Caplan.
But just because we could do it doesn’t mean we should. Cloning is a risky business. We know that cloned animals often die in the womb, and that if they are born at all they sometimes have physical deformities and live unnaturally short lives. There would probably be many deformed and dead Neanderthal babies long before a healthy one comes along. Their resurrection through cloning puts the lives and wellbeing of surrogate and baby at stake … to what end? No woman should ever have to endure the uncertainties, the psychological and physical trauma of carrying another human species to term. The risks are just too great. It’s with very good reason that human reproductive cloning is illegal in over 50 countries.
In 2006, Francis Collins, director of the Human Genome Project, argued: ‘Scientists, ethicists, theologians and lawmakers are essentially unanimous that reproductive cloning of a human being should not be undertaken under any circumstances … Implanting the product of human SCNT [cloning] into a uterus is profoundly immoral and ought to be opposed on the strongest ethical ground.’ Others have called it ‘criminally irresponsible’. If we recognise, as we must, that Neanderthals were basically human, related closely to us in evolutionary time, then we must award them the same moral status, rights and privileges that we grant ourselves. Neanderthals should not be cloned.
Researchers have pored over the remains of more than a hundred Neanderthals, scattered across time and geography. From them, we know more about Neanderthals than any other extinct hominin. We know where they lived, when they lived and how they lived. We know what they ate and how they hunted. From the fossil and genetic record, we can even make educated guesses as to their behaviour, personality and thought processes. We know what they looked like, right down to their skin and hair colour. We can use computer modelling to put flesh on their bones – we don’t need to do it for real. We can study their genes by adding them into cultured cells, we don’t need to bring back an entire individual. There is little to be learned from a de-extincted Neanderthal person that we don’t already know.
In the meantime, anthropologists continue to argue passionately over the interpretation of Palaeolithic fossils, and the debate over how sophisticated Neanderthals were continues to swing back and forth. While it’s obvious that Neanderthals weren’t as cultured or erudite as our modern selves, we’re in no danger of reaching a consensus on how they compared to Ice Age modern humans any time soon. Nor can we agree on why they went extinct. But Hermann couldn’t help with any of that. He wouldn’t have the answers. This Neanderthal would be very different to those who battled the elements tens of thousands of years ago. A product of nature and of nurture, his DNA might be similar, but Hermann would be growing up in a very different world to the one his ancestors evolved in. He’d be exposed to fast cars and fast food, social media and smart phones. He’d grow up in a time of consumerism, global superpowers and boy bands. He could never be the mammoth-hunting caveman of the past. Anyone hoping for some kind of loin cloth-wearing freak show would be disappointed to find a twenty-first century Neanderthal reassuringly normal. If you were sitting next to him on a park bench, you’d probably never raise an eyebrow. Hermann, as I hope I’ve convinced you, would be so average as to blend in with the other seven billion humans on the planet.
A subject of intense research efforts, we’ve also learned recently how the environment can influence gene activity via a process known as epigenetics. What we eat, drink and smoke, our social status and even the care we receive as children has the potential to permanently alter the way our DNA works. Hermann might have an Ice Age genome, but it would be influenced by his twenty-first-century upbringing. His patterns of gene activity would be different to those of his genuine Neanderthal ancestors. As a result, he might look or behave differently, or perhaps succumb to different diseases. Genetic puritans (or ‘molecular biologists’, to give them their proper name) will tell you this Neanderthal would not be the real deal. His would be a genome out of time. The only way to find out what Neanderthals were really like would be to build a TARDIS and travel back forty thousand years or so.
Have I convinced you yet that there is little to be learned from bringing a Neanderthal back to life? It’s my strong belief that just because we could de-extinct a Neanderthal doesn’t mean we should de-extinct a Neanderthal. It’s precisely because they are so similar to us that this experiment should never be allowed to happen. Resurrecting a Neanderthal, or any other extinct human species, is a line that should never be crossed.
No Sex Please, We’re Neanderthals
But maybe we don’t need to bring the Neanderthals back. Maybe their legacy is still with us. When Svante Pääbo decoded the Neanderthal genome, he compared it with the genomes of modern humans living in different parts of the world today. What he found surprised everyone. To that point, all the evidence had suggested that Neanderthals and the modern humans they lived alongside had kept their relationships platonic. But Pääbo’s results suggest something much more intriguing. The genomes of people from Europe and Asia contain traces of Neanderthal DNA. Tens of thousands of years ago, Neanderthals and modern humans interbred, creating children and a genetic legacy that still exists today.
Others, including geneticist Joshua Akey from the University of Washington, have since confirmed the findings. People of European and Asian origin carry between one and four per cent Neanderthal DNA, while people from Africa carry none. The implication is that, after they left Africa, modern humans bred with Neanderthals. The humans that remained in Africa never had the chance to meet a Neanderthal, much less invite them back to their cave, so their genomes are Neanderthal-free.
Although the total amount of Neanderthal sequence in any modern human is relatively low, the cumulative amount of Neanderthal DNA that persists across all humans is a staggering 20 per cent. From his data, Akey estimates it took around 300 successful ‘hybridisation events’ to end up with the pattern of Neanderthal DNA seen in living people today. Of course, modern humans and Neanderthal may have had sex more often than this. ‘Maybe at the time, modern humans didn’t find Neanderthals as different as we do today,’ says Akey, but their trysts may not always have resulted in viable pregnancies. ‘They may have been on the fringes of biological compatibility,’ says Akey.
That vast swathes of the cultured, educated, shaven, Western world are part-Neanderthal may come as something of a shock. You may not know it, but you may also be part-Neanderthal. But you don’t have to take my word for it. Anyone can take a test to find out how much of their genome is of Neanderthal ancestry.
And so it came to pass that one sunny, summer evening I announced to my husband that I was going to do a DNA test to find out how Neanderthal I am. ‘Do you really need to take a test to work that one out?’ he replied. He’s a funny man. Several days later, as the shoe-shaped bruise on his cojones began to fade, I broached the subject again. ‘Fine, fine, do whatever,’ he said quickly. For $99 (plus postage and packing), you can send your spit to a US company that will analyse your DNA and help unravel your ancestry, including your genome-wide percentage of Neanderthal DNA. Outside, our three children were taking it in turns to pin each other down, swing from trees and catapult chickens off the trampoline. What if I really did carry Neanderthal genes and had passed them on to my children? Could it explain their rambunctious behaviour, their instinct to brawl and blatant disregard for animal welfare?
I registered online and paid my money, then four days later, the postman delivered a parcel; a box in a padded envelope in a padded envelope … because you can’t be too careful when it comes to protecting your DNA. The box was the size and shape of a disappointingly proportioned chocolate selection, but it had the words ‘Welcome to you’ printed on it and lots of colourful chromosomes emblazoned on the lid. Inside was a high-tech tube and an instruction leaflet that advised me to stop eating and drinking for 20 minutes then spit into the tube. It was the longest 20 minutes of my life. Walking away from the biscuits and endless cups of tea that supplement my working day was arguably one of the hardest things I’ve ever had to do. Fortunately, spitting into the test tube was much easier, as was popping the tube shut, shaking it up a bit and slipping it back into the pre-paid envelope that carried it all the way back to California and the shiny labs of DNA testing company ‘23andMe’.
Two weeks later an email dropped into my inbox to tell me that my initial report was ready. Like a teenager waiting for an exam result, I nervously logged on to the company website. The results were in. First up, a few things that came as no surprise but that reassured me the results were genuine. My DNA is 99.9 per cent European, of which I’m 53 per cent Northern European and 38 per cent Eastern European. My dad was from England, while my mum is from Lithuania, so that sounds about right. Then I have a dash of Ashkenazi (1.4 per cent) and Southern European (3.8 per cent), and an even smaller smattering of East Asian and Native American (0.1 per cent). Perhaps there are some family secrets hiding in the boughs of the Pilcher family tree. Next up came the news that I have one new second cousin, 171 fourth cousins and 817 ‘distant cousins’ that I never knew I had. Suddenly the Christmas card list is looking daunting.
And then came the moment of reckoning. The average 23andMe punter, the website tells me, has a genome containing 2.7 per cent Neanderthal DNA. But my genome contains 3 per cent Neanderthal DNA. I tell my husband. He retreats to a safe distance then says, ‘Is that all?’ This means I have 0.3 per cent more Neanderthal DNA than the average person, which puts me in the 91st percentile for Neanderthal-ness. I am officially a cavewoman.
I’m not sure what to make of it. The truth is that no one knows exactly what all of the Neanderthal DNA that persists in today’s modern humans actually does. There are some areas in our genomes where there is little or no Neanderthal DNA, and others where there is more than expected, evidence that some sequences were advantageous and so positively selected for, while others conferred no benefit and were lost over time. Single genes influence many different things, so the DNA I’ve inherited will probably have diverse effects. Many of the Neanderthal genes that live on in people today, studies suggest, appear to influence skin pigmentation and keratin, a protein found in skin, nails and hair … which could explain why I have the hairstyle of Stig of the Dump, which I’ve been insisting for years is genetic.
Suddenly it all begins to make sense. I can never find a hat that fits. I have hairy toes. There isn’t enough wax in the world to tackle my bikini line. My children, also part Neanderthal, don’t just get their spirited behaviour from me and my husband. We can pass the buck to some prehistoric person who spent his days chasing mammoths and his nights sleeping in caves. It can explain why they like camping outdoors, playing with fire and hitting things with sticks. This is excellent, excellent news, especially if they turn out to be as benevolent as their Nandy-caring antecedents.
I’m pleased to be more ‘caveman’ than most. For too long, Neanderthals have been hapless stooges. They’ve been maligned and misunderstood. But perhaps now, with the discovery that so many of us are a little bit Palaeolithic, things might start to change. We don’t need to resurrect them – we should never resurrect them – to know that Neanderthals were resourceful and resilient, compassionate and caring. They lived sustainably in their Ice Age world for hundreds of thousands of years without wrecking it, while in the comparably short time we’ve been around, us modern humans have made quite a mess. Perhaps it’s time the word ‘Neanderthal’ stopped being used in the pejorative and started to be used as a compliment. I say it loud, I say it proud: I’m honoured to be part Neanderthal … and I will never wax my legs again.
NOTES
1 OK, so there aren’t any i’s, but there are t’s, c’s, g’s and a’s.