WHEN OLD MAN La Chapelle either lay down to die or was interred in the small cave, he bore already the marks of someone who had been cared for in life. Maybe even loved. Common to many Neandertal skeletons, his bones—discovered in 1908 at La Chapelle-aux-Saints in the Corrèze just east of the Dordogne—showed all manner of stresses that came with being a nomadic, big game hunter who worked with others to get close to wild animals with nothing but jabbing spears. It was a hard life, and many Neandertal bones, not only his, show a story of healing after severe injury.
The others didn’t abandon the severely injured to die, but instead cared for them and extended their lives. Some think it was sentimental human love at work and some think the injured individuals carried knowledge and valued skill, such as tool craft, that was important for the group. As usual, the answer is more complex. They were human and like us, emotional. We all have been for a long time. Chimpanzees and bonobos prove it, for they too are a sentimental bunch. Outside of genetics, scars and healed bones are the single best evidence for the nature of relationships in the Paleolithic. Unlike genetics, they carry a more certain emotional valence. We can’t imagine so well how the genes got exchanged, but to aid a handicapped person speaks of empathy, compassion, and group identity.
Old Man La Chapelle lived around 50,000 years ago and is called that because he died older than many of the same era, somewhere in his late thirties or early forties. He suffered from terrible arthritis, had a healed broken rib, had a lot of degeneration in his hip, and had lost most of his teeth. All of these features would have cut his life short if he had no help from others.
As María Martinón-Torres, one of the key fossil specialists with the team excavating at Atapuerca, said, “It’s good! If you had scars, you survived!” This she exclaimed enthusiastically during her recent talk at the Collège de France in Paris. Presenting the findings from Sima de los Huesos, and going over the seventeen of the twenty-eight individuals who had skulls associated with their bodies, she was giving a pretty macabre profile of how they all lived and died. The audience especially appreciated her enthusiasm as they learned about arthritis, tooth infections, and crushed bones. Almost all of the Atapuercans had scars of one form or another, scars that they could not have earned had they been abandoned when their wounds were fresh. You have scars, you survived, this is good, because you were strong and had a strong social network that didn’t toss you into that pit of bones before your time. As far as we can tell.
The skeletons at Shanidar tell a similar story. They are a collective of skeletons, eight adults and two infants, of individuals who lived there at different times (so not a related community). Some of the skeletons came to rest in the cave due to collapse from the cave ceiling, hardly an intended burial. But even these show the signs of healed old injuries before the final crush.
The best-studied skeleton is Shanidar 1, none other than the inspiration for Jean Auel’s endearing father-uncle-shaman character, Creb. In the novel as in real life, he was handicapped from several severe traumas. He, too, was considered old upon his death sometime in his forties; he had healed from numerous dramatic injuries before then. His face’s left side had been crushed in and that most likely took out his left eye. He had a huge gash that had healed on the right side of his skull. His right foot had a broken bone in the arch that had healed but would have severely handicapped his gait while doing so. He was missing his right forearm—it appears to have been lost or amputated—and his right upper body shows atrophy compared to his left side. He also had advanced arthritis in his right foot and up to his right knee. All these things occurred long before he died and spoke of someone who was helped many times along the way. He may have lived 35,000 to 45,000 years ago.
By contrast, another, Shanidar 3, who may have lived around 50,000 years ago, had a gash sliced into his ninth rib, a cut very much like those caused by a flint edge. While he too had healed wounds from prior traumas, it appears that it was either the deep jab that killed him, or rock fall in the cave soon after his injury. One of the troubling aspects of his wound is that he may have been attacked by early modern humans, who would have been in the Levant by then and in possession of spear-throwers— atlatls—that had the velocity and projectiles to make the deep gash that Shanidar 3 suffered. Were these early modern humans intentionally attacking from a distance, or had Shanidar 3 been hurt in a hunting accident as they tried to take down the same large game animal?
Likewise, at Atapuerca’s Sima de los Huesos in Spain, where several of the skeletons show the signs of care and healing, one shows signs of possible violence, two sharp puncturing blows into the skull.
Then there are the cases of cannibalism, such as at El Sidrón in Spain, Krapina in Croatia, and Les Pradelles in southwestern France, which we can hardly decipher and sort between ritual versus survival cannibalism (or simply funerary defleshing of the bones without eating, though the smashed bones that look as if the marrow has been sucked out make this harder to argue).
These issues about relationship that show up in the archaeological record, from cooperation to competition, have been with us a long time. Chimpanzees also exhibit this polar set of traits. So do wolves, and many other mammals, but the difference among humans, both Neandertals and us, is not only the degree and style, but that cooperation became stronger among us. Evolutionary biologist Edward O. Wilson calls this “group selection,” when natural selection goes for group-level traits that help everyone survive better, rather than selecting at the individual level. Such traits are both cooperation and competition: the two sides of tribalism.
Our coordinated hunting and foraging, living together against the elements and others, is a part of what made this form of selection strong. It is deeply apparent in Neandertals. First, it can be seen in the types of hunting that they did, which required incredible planning, coordination, communication, and cooperation. And second, it can be gleaned from the acts of empathy that led to healed bones, to greater longevity, and to selecting for the group socially and emotionally, rather than leaving individuals to fend for themselves.
These two odd bedfellows—cooperation and competition—are within us and have been for a long time. In a sense, they are the root of all modern human mythic stories of the battle between dark and light and the incessant need to balance these forces all the time. The side of light is strong within us and so is the dark side. Experiments with chimps and bonobos have shown that while they have cooperation, it is a feature stronger and more complexly expressed in humans. Given, again, that Neandertals are our closest kin, from whom we split off around 700,000 years ago, if we’ve got it, and chimps have it, surely they did too. But beyond cooperation in the hunt and caring for the ailing, we have little idea how else it was expressed.
Once, I naïvely asked Jean-Jacques, “What would be the best discovery that would help bring more definitive insights to our understanding about the Neandertals?” I was sure he would say, “a skeleton, in situ, never disturbed by us moderns.” It seemed obvious to me. A skeleton that hadn’t been dug in a manner that removed precious evidence and context or that declared something conceptually huge, such as a ritual burial, before all the data was considered: that could offer such a fresh start. It could help lay to rest these unresolved debates in the field.
So his answer surprised me. “I don’t want a new Neandertal skeleton,” he said. “I want to know what his or her relationship was with his or her family-in-law! This is a bit hopeless I know, but maybe we’ll learn more in the future about developmental aspects that have strong social implications, like, for example, the age of weaning. I’m more optimistic on this side.”
WHEN I SAT in the reclining dental chair, I began right away to talk about Neandertal dentition with my dentist, Dr. H. He had told me that in dental school they study the evolution of human dentition as par for the course, so he was familiar with Neandertals and their oral health. It aided modern dentists in understanding the human lineage and dental issues. It also horrified them to see the levels of decay we moderns have with our high-carb, high-sugar, and processed diets. Neandertals may have had wear issues, and broken teeth that caused infections, but decay was rare compared to today. The Paleo diet is good for your teeth, provided you don’t use a flint blade near them to cut the meat, or use them as a third hand to process hides.
Wanting to hear Dr. H’s take on things, I planted a seed before having to open my mouth for investigation. “From looking at the Old Man of La Chapelle’s lack of chewing teeth,” I said, “they say he was cared for, that others helped him eat.” I leaned back and opened wide.
Dr. H began to probe, much like a paleoanthropologist, using his own excavation tools, going into caves and analyzing fossils. Teeth are the most mineralized bone in our bodies and in a sense are already fossils while we live, a reason why they survive longer than other bones in the paleontological record.
“That he was cared for,” he said of La Chapelle while checking my molars, “doesn’t mean he was necessarily liked. It just means he was important to keep alive. Maybe people feared him. Maybe he carried important knowledge. Maybe he told people bad things would happen to them if he died, if they didn’t chew or mash his food for him. Maybe he was a terror of a patriarch and held magical powers.” My romantic bubble burst. Dr. H moved his probing to other areas of my dental cavern. “Maybe we just don’t know if it was compassion or fear or even a mix,” he continued. “Look at how we handle growing old today; it’s a mix of compassion and fear.”
I swallowed this as he worked in silence for the rest of the time before asking me to rinse. Maybe Mr. Chapelle was a conjurer of dark, inexplicable forces and people were frightened that if he was not content, he’d bring these forces down on them. Maybe that was also why he was set in a small cave. Equally, he could have been beloved, set there for respect and reverence. Or convenience. Obviously, we can spin this a lot of ways.
I prepared also for what I knew was the next line of conversation (it always was), that I grind my teeth. It was an unfortunate habit probably acquired during the high-anxiety years in graduate school, working and going to school full-time, and I never shook it off. No matter how much yoga and meditation I practiced—both recommendations from Dr. H—my grinding habit didn’t diminish. It was my existential crisis as a creature with a grammar that allowed me to speak about, not only think about, the past and the future, share it and hear it from others, amplifying our anxieties over past regrets and future fears. The glassblower from Toulon was right: language was a block to living more fully—to being in the present tense. It was rigid intellect, one that defined and minced things that were not present and didn’t even exist. Yet. Grind.
This time, I thought I’d preempt the discussion. I rinsed and said, “Neandertal teeth show bruxism more radical than my own.” I rinsed again and spit. “I bet their teeth looked worse.”
He didn’t skip a beat—he cares about his patients, even when they apply heavy coats of denial. “But, Beebe, they didn’t have the processed foods we have now. And they didn’t go through the agricultural revolution that tamed and domesticated tough-to-chew foods as well as dramatically reduced the size of our teeth. They processed wild seeds, nuts, and meats with their teeth alone and that would cause the wear and tear. That’s different from unexamined nighttime anxieties and unconscious grinding, which don’t do anything to feed you. And they also used their teeth as tools, like a third hand, which I certainly hope you do not.”
Slam dunk. My mouth hung open of its own accord.
“DO YOU THINK Neandertals needed to meditate?” I uttered the thought aloud as I met my friend Bruno for coffee at the Café de la Mairie in Les Eyzies. He’d been immersed in all things Neandertal and early modern human as a neighbor to Les Eyzies all his life. These woods and cliffs had been his playground as a boy. Later, as a teenager, this café had been his scoping grounds with other teenage boys, riding their bikes here in high anticipation of the pretty foreign girls who came to their prehistoric shores to visit the caves. Prehistory had sex appeal, and he was a native son.
“No, I don’t think so,” he said after a long quaff of his coffee, and serious thought. “We’re the uptight humans, not they.” Homo materialensis uptighticus.
Everyone in Les Eyzies knew Neandertals had the more flexible and Zen intellect. This was common knowledge here in prehistory central. Neandertals didn’t show the compulsion to control the world around them as we do. Anxiety and OCD levels of control may be in some big way the origins of religion and the birth of conscious meditation. (When you hunt, gather, fish; work stone, wood, and bone, you naturally meditate. It seems its when we stop doing these sorts of things that the modern mind shows its discontent.)
With the new era dawning thanks to the genetics revolution and also cleaning up our nineteenth-century bigoted ideas about our hominid kin, let alone our own kind, Japanese fine artist Kentaro Yamada recently came out with a new fragrance called Neandertal. A master stone knapper made him a flint Mousterian hand ax of the Acheulean tradition, and he used it as the prototype for a ceramic perfume bottle, one in white for women, and one in black for men, and then worked with a Scottish perfume designer to create the fragrances with which to fill them. They strove to hit the perfect fragrant notes that would capture who Neandertals would have become had they survived into the last 35,000 years.
“If Neandertal[s] had survived,” Yamada wrote whimsically on his website, “they could have created [an] extremely sophisticated civilization differently shaped from ours. The fragrance is designed for the Neandertals, and it will reflect their life in the past as well as their sophisticated future, which they could not see themselves. As we possess 1–4 percent [now revised to 1.5–2.1 percent] Neandertal DNA within us, this perfume can also be applied to humans. Smell triggers memory above sight and hearing, and it can unlock doors to their shadows hidden within our DNA.”
Channeling Harold as I read about the new perfume (of course, I wanted a bottle), I knew he would add that both of us—Neandertals and early modern humans—had been pretty smelly, what with all the rotting meat we processed in our cave and open-air sites, and the lack of regular showers and deodorants. Smelly, cold, and hungry were some of the frequent adjectives that arose around the campfire as we tried to re-create life in the past.
We modern moderns, living now with our baths and toiletry products, have lost a lot of the signals our sense of smell tells us about the world and beyond. Smell not only triggers memory but can pleasantly or unpleasantly, depending on the situation and subjective sniffer of the person, trigger personal contact before anyone touches. A few long hot days on the dig, and we had direct experience of this and how a cave and trench can funnel smell into more concentrated bombs. Those days, we romanticized the past less and couldn’t wait to hit the showers. On other days, with pleasing temperatures and a soft forest breeze, the romance returned. Neandertal. I liked that Yamada also had dropped the “h,” which went further to unlock doors to their shadows and light hidden within our DNA.
DURING THE FLOW of five dig seasons over five years at La Ferrassie, from 2010 to 2015, news from genetics delivered several bombshells, first about interbreeding with Neandertals, then about the discovery of the new archaic humans called Denisovans, whom we had never known about. Moreover, we learned that in our many episodes of interbreeding, there was potentially one other (and maybe more) unidentified archaic human population(s) whose doors we had yet to unlock within our DNA.
The very day in May 2010 that I had spied Harold and Dennis fleeting through the market square as I purchased shallots, Richard Green, Svante Pääbo, and a consortium of some forty-eight more coauthors and collaborators on the Neandertal genome project published their influential paper in Science on the first successful sequencing of nuclear Neandertal DNA. Its impact was huge. It was hard evidence that gene flow was frequently going on between Neandertals and early modern humans. It was hard evidence for what paleoanthropologists saw in fossils they’d identified as hybrids. It was hard evidence for what we all know, that humans of all ilk have a healthy sexual appetite, going at it with adventurous gusto, seeking the exotic as much as the familiar. It was hard evidence that we had not only enjoyed liaisons with Neandertals but that those liaisons contributed to adaptive genetic traits that helped us overcome new diseases and afflictions unfamiliar in the new environments of Eurasia. It also opened a new door, and genetics became a third major player with paleoanthropology and archaeology in the study of human evolution. From that moment onward, each week it seemed, breaking news kept, and continues to keep, hitting the journals and news on new findings from the burgeoning field of paleogenetics.
This path in the field in many ways began to change in 1987 when Allan Wilson, Rebecca Cann, and Mark Stoneking at Berkeley published their work on human mitochondrial DNA. Mitochondrial DNA is a single circular structure composed of 16,569 nucleic acid base pairs found within every cell’s mitochondria, the energy producer for the cell that exists outside the nucleus. It is one of two varieties of DNA humans have, this one almost exclusively inherited from our mothers. Nuclear DNA is far larger (3.3 billion base pairs) and more complex and is made up of forty-six bundles of DNA in the form of chromosomes. We get twenty-three chromosomes from our mothers and twenty-three from our fathers, each set carrying genes for the same functions but in different variations from each parent. It’s the way we each turn out looking both similar to and different from our parents and their parents and also keep evolving (plus adding our own mutations to the pool) and having diverse options for adapting to present and future situations.
Wilson, Cann, and Stoneking sequenced and analyzed the mitochondrial DNA (mtDNA) because it was the best place to start in the burgeoning field of genetics of the time: mtDNA is smaller and more stable than nuclear DNA. They took mtDNA samples from 147 people around the world who represented the most diverse sampling of humans living today and discovered that we are all related and we all originated from a related maternal lineage from Africa. That undid a lot of prior theories about human evolution and also rebuilt some more complex and accurate ones.
It also mapped a possible chronology that our variation of human, Homo sapiens, began to emerge as a distinct meta-population around 200,000 years ago, though we we have changed a whole lot since then, especially in the last 50,000 years. It confirmed that we did all this in Africa and then migrated out into the rest of the world (and back again, for nomads are not unilinear). It also proved that all humans living today are incredibly closely related, in fact, so closely that it seems we are survivors of a bottlenecking event that reduced the wider number of ancestors we had (who therefore did not pass on their genes) down to what appeared as one specific population, one small group of women, all who carried the same related mtDNA, which we all carry.
This work became the foundation for the “Recent Out of Africa” theory, which has become a dominant idea about our recent evolutionary history. Another theory, the “Leaky Replacement Model,” factors in the evidence for the low-frequency (but still frequent) interbreeding among different human groups—what the pros like to call admixture. It sees Africa as the origin of Homo sapiens but also that regional histories of interbreeding with other, more archaic groups are also a part of the formula, rather than all-out replacement by Homo sapiens. Both are theories and reflect how different scientists interpret the data from the fossil record and the new genetic evidence. The work from 1987 began this development toward more nuanced ideas about human evolution. But the work more recently, on sequencing the more complex nuclear DNA, both of huge samples of modern human populations and also of archaic humans—Neandertals and Denisovans—has deepened our ideas and loosened us up for more unexpected twists and turns in the future.
Dash any idea of those simple lineage charts we all grew up with. They are artifacts of an order-and-neatness-loving brain, not true maps of what happens in real life.
In 2008 Pääbo and his team first sequenced the mtDNA from a 38,000-year-old Neandertal bone from Vindija. This initial result showed that, based on only the mitochondrial genetic material—which is matrilineal—Neandertal genetic diversity fell outside of the range of our own widest range of mtDNA diversity among living humans around the world. It made it appear as if we had no interaction, an idea that was to be proven simplistic.
The nuclear DNA sequence from three Neandertals from Vindija made up the sample sequence, which was published in 2010, and this has become a part of a growing database for documenting Neandertal genetic diversity. It has also been a source for comparisons with us. In 2010, the scientists saw that we modern humans from Eurasia had received 1–4 percent of our DNA from Neandertals. With the growing and more accurate work since, that number is now adjusted to around 1.5–2.1 percent DNA that Eurasians have in their genes from Neandertals. Moreover, North Africans possess around 1 percent, filling in a gap that was glaring, that there had to have been migration back into Africa as well. Even though Neandertals never lived in or migrated into Africa—we have yet to find their fossils there—modern humans bearing their genes did come and go in Africa. For sub-Saharan Africa the percentage is smaller, perhaps around 0.7 percent. Africa is the second largest continent and has the world’s most diverse populations living within it, the latter a legacy of our own origins there. We began there so we’ve had the longest track record there; genetic diversity will therefore also be the most expressed there.
All these noted percentages will likely continue to be adjusted as the database increases with more samples, but the bottom line is that we all have a little bit of Neandertal ancestry in us. Those who have more selected traits from Neandertals are likely here today because those traits helped them thrive in those early migrations into Eurasia. They in many ways can thank Neandertals for their survival. The 2010 paper and ongoing work since have shown that natural selection played its hand many times, positively selecting for certain advantageous traits from the Neandertals, such as in areas affecting our skin and hair, metabolism, cognitive development, and skeletal development.
Right around the same time, in 2010, Pääbo, David Reich, and their team also published on a sequence from a pinky bone of a young girl from Denisova Cave in the Altai of southern Siberia, thinking it belonged to a Neandertal—as they were known to have occupied the cave site. But the sequence had a different pattern, outside the range of variation in modern humans and in Neandertals, and this was the first time genetics discovered a new fossil ancestor rather than paleoanthropologists and archaeologists.
The genetics indicate that these ancestors, called Denisovans, were closely related to Neandertals and had branched off sometime after we and Neandertals had branched off from each other, from our common ancestor, around 700,000 to 800,000 years ago. We went on to become modern humans and Neandertals went on to become Neandertals and then somewhere in that process, Neandertals split off from a related population as well and that population went off in its own isolation to become Denisovans.
That little Denisovan girl and her powerful pinky had lived around 50,000 years ago in the Altai. Since the discovery of distinct genetic signature, a few more small fossil bones that also reveal Denisovan genes have been sequenced from the same cave. The work has been expanded to see if modern humans might also have Denisovan genes in the way that we have Neandertal genes within us.
As one would expect, given our track record for liaising with everyone we meet, we do carry Denisovan genes. Living people from Australia, Papua New Guinea, and some South Pacific islands carry as high as 4–6 percent Denisovan genes. People in mainland Asia carry less on average but more than Europeans. Denisovans seem to be an ancient form of humans who inhabited eastern Asia and then the southeast, and who encountered early modern humans who were moving into their territories around 50,000 years ago and perhaps earlier. They potentially mingled—admixed—in Asia, before the early modern humans then made their crossings into Australia and the Pacific islands.
But the Denisovan fingerprint also appears in the mtDNA of the Sima de los Huesos Neandertals, Europe’s earliest Neandertals known to date—which doesn’t say Denisovans lived in Iberia, but does confirm that they and Neandertals were a sister group that split off sometime after 800,000 years ago. Perhaps the Sima Neandertals were members of a more recent splitting. It’s clear that they were firmly on the path of Neandertaldom, though, because their nuclear DNA—much more involved in the dance of genetic inheritance—is firmly within the genetic signature defined by the Neandertal meta-population.
One useful way to think about human evolution is a phrase straight out of all the genetic publications: “turnovers and migrations.” These terms capture well the bushier and bushier lineages in our evolution, some that were successful and passed on their genes, and others that went extinct and their genes with them. Human evolution is a study of turnovers—gene flow, expansion, extinction, mixing, and mingling—and migrations, always on the move, wanting to see what’s good to eat over the next horizon. (It’s safe to say, then as now, as much as we love sex, we are even more motivated by what’s for dinner.)
It seems dizzying but it is in keeping with human nature. More recent breaking news from genetics is that eastern Neandertals were different from western Neandertals and that ancient Homo sapiens from Africa some 100,000 years ago gave the eastern Neandertals a good time, leaving some genetic signals to prove the fact.
John Hawks, a very publicly engaging paleoanthropologist, wrote in his blog, “The evidence now shows that introgression from Neandertals into modern human populations happened multiple times, and likely in multiple places.” Paleoanthropologist Alice Roberts wrote more colorfully on Twitter, “Prudish paleoanthropologists are struggling to come to terms with the promiscuity of ancient humankind.”
Genetics, coupled with fossil morphology and archaeology, is showing us that there were many migrations out of Africa, and back again, that define who we are today. And who we are seemed to show a trailhead toward modern humanness that showed up around 200,000 years ago in Africa, both genetically and morphologically, and that had several turnovers and migrations within Africa as well as without.
Beyond Africa, the first major turnover and migration concerning early modern humans appears to have happened around 120,000 years ago, aligning with the early modern human fossils found in Israel at Qafzeh and Skhul that date to that period. They occupied the Levant, which had already been occupied early by Neandertals, and also later by yet more incoming Neandertals on their own path of turnovers and migrations from Europe. Somewhere in all this the two meta-populations probably interbred here several times when they intersected and co-inhabited the region. Some of those Neandertals and their hybrid and fertile offspring may have migrated farther east, where the earlier early modern human genes have been found in the Altai Neandertal population. Curiously, no human living today has genes from that population of early modern humans, so we know they went extinct.
The same seems true for an early modern man who lived 37,000 to 42,000 years ago in today’s Romania, found at Pestera cu Oase. He had Neandertal relatives four to six generations before his own and he too carried early modern genes that have gone extinct from the contemporary population. It’s another reason why we probably have less Neandertal DNA in us than we could—because many groups within our own meta-population went extinct. It also reinforces the idea that some sort of a bottleneck event, or events, took place to define the relative lack of great genetic diversity found in living people today. We are more related to each other now than we probably have ever been in human history or prehistory.
Genetics was helping to break down cemented conceptual walls in paleoanthropology to get at real behavior, recorded in mating outcomes. One of those walls was a prudish attitude toward past sex lives. Another was the simplistic labels and overly bounded ideas regarding different categories of being human. People have now begun to speak about Western, Central European, or Eastern Neandertals instead of Neandertals as a single undiversified group. Any day now—from what I hear from the experts—China will recognize that it has had Neandertal—and Denisovan—fossils all along and soon the natural corridor of turnovers and migrations in the past, before limits imposed by national boundaries and border controls, will be open once again.
While genetics can tell us what sorts of gene-swapping we did, and even estimate when based on models for mutation rates, it can never tell us how or what these encounters were like. Were they romantic or violent encounters? Probably both and a variation in between and to different frequencies, all depending on the people and the circumstances involved. Taking into consideration modern humans and our other surviving closest relatives, chimpanzees, it is a safe bet that all ranges of cooperative to competitive dynamics were possible. But, still, we can’t know.
Genes aren’t the only thing being analyzed on DNA. So are the extra-genetic molecular signatures, the epigenetics, those molecules attached to DNA that regulate what genes are expressed, how, and what genes are turned off, on, or kept turned off. It is an area that helps explain how we can share so much common ancestral DNA and yet look so different. Epigenetics also can effect faster adaptive changes to an organism than full-on genetic sequence changes from mutations and natural selection. It’s essentially a way that the same gene is shared between species but used—regulated—differently within each.
One way to get at this dynamic is through tracing the pattern of deterioration left by methylated groups, areas on the genome where a methyl group, CH3, is attached. This is a part of the mechanism involved in regulating—turning on and off and expressing—a gene. The patterns for areas that are methylated and not methylated are different between modern humans and Neandertals, even when associated with the exact same gene, and this may help explain why we look different in signature ways.
Not only this, but consider these wild and nutty facts from genetics, courtesy of Jean-Jacques: humans share 18 percent of their DNA in common with plants, 26 percent with yeast, 44 percent with fruit flies, 92 percent with mice, 98 percent with chimpanzees, and 99.7 percent with Neandertals. It’s a different sort of family tree, one on the full tree of life. It tells us how interconnected we are with all life on earth and also that something more dynamic than just genetic flow and changes is at work to come up with the vastly different appearance of a human, a mouse, and a chimpanzee. It gets more subtle but as dramatic to contemplate with our closest kin, Neandertals, whereby a dance of switching genes on and off in a complex orchestrated methylation ballet, we still carry very similar genomes but can turn out looking different, best suited to adapting to where we are.
“Similarity between genotype,” Jean-Jacques concluded, “does not mean that the phenotypes are similar. We are ninety-eight percent similar to chimpanzees but we are far from looking like a chimpanzee.” It’s not just the pow packed into the 2 percent that is different, but what epigenetics is uniquely doing to the whole package.
UNDERSTANDING THE DIFFERENT percentages can still be confusing, especially what might be going on in that .3 percent that is unique to Neandertals, portions of which we carry within us. To nail this down better, I turned to molecular anthropologist Theodore G. Schurr at the University of Pennsylvania, who works on dozens of human ancestry projects around the world and is as deeply trained in the four fields of anthropology as he is in genetics and molecular biology. His broad experience and open manner made it easy for me to ask seemingly basic questions. We met in his office in Philadelphia at an opportune lull between his field projects in the Old and New Worlds that take the study of turnovers and migrations to the widest possible scope.
“The science now estimates that modern humans share 99.7 percent of our DNA with Neandertals,” I began, “and it also says we got about 1 to 4 percent of our DNA from them. Does that mean that it is this remaining 0.3 percent that is unique to Neandertals where we received our 1 to 4 percent?” (We talked before 1.5–2.1 percent became the more recent revised estimate.)
“In a basic sense, what this means is we are far more like Neandertals than we are any other hominids that we know of so far. We’re closer to Neandertals than we are to Denisovans, in terms of sharing some large component of our genome. And we’re certainly closer to any of the Denisovans and Neandertals than we are to the chimpanzees—which represents not our common ancestry with chimps, but an entirely different lineage, which extended from a common ancestor six, or seven, or eight million years ago. Each lineage is the result of a long process.”
“So the 99.7 percent that we share with Neandertals is our common . . .”
“Our common genetic makeup or ancestral stock, if you will,” he said.
“And that remaining 0.3 percent? Is that where they diverged separate from us, in their own unique genetic expression?”
“That’s right.”
“And that’s where we’re getting that 1 to 4 percent [1.5–2.1 percent], from interbreeding?”
“Yes, that’s right,” he said. “There are different models for this but essentially, in a basic sense, you have a common archaic form, whether it’s heidelbergensis or whatever [erectus/ergaster/antecessor, for instance], out of which you have both Neandertals and modern humans arising. The Neandertal branch somehow makes its way into Europe and it begins to diverge from that which existed in Africa, from which modern humans came. So there’s still hundreds of thousands of years of time that separate those lineages back to when they had a common stock. That six hundred thousand years or whatever amount of time that goes on is when you have a divergence of those two forms so that you can distinguish their makeup—Neandertal-specific markers and modern human–specific markers—so when they come together later to mix, you get hybridization.” So we parted ways for a while but then came back, each different for that separation, and met up and were still able to get it on and have some viable offspring.
I had heard some paleoanthropologists say that early modern humans absorbed them, that we folded Neandertals into the whole flow of things. These scholars are largely associated with influential paleoanthropologist Milford Wolpoff’s philosophical position, which proposes Neandertals were never a separate species because of gene flow and never went extinct. If that were the case, wouldn’t we see more genetic material from Neandertals? I asked Theodore.
“If that were true,” he replied, “then we would see much more extent of Neandertal markers than we do; if there was extensive admixture, then we would see much more extensive admixture.”
“You mean, if we really absorbed them, then we would have far more DNA from them than the percentage we actually have?”
“I would say we would have a greater extent of admixture,” he said. “We don’t have a complete replacement of Neandertals. [Likewise] you don’t have people who are 97 percent Neandertal and 3 percent modern, or even people who are 50–50. There’s not a clear mixture or merger of the gene pools. That just didn’t happen.”
He reminded me of something Svante Pääbo had recently told the audience in Paris at the Collège de France, about the way these percentages add up. He was there just a week before María Martinón-Torres arrived to deliver her exuberant talk on the Atapuerca twenty-eight.
Of possessing 1.5 percent Neandertal genetic ancestry, “It’s as if you have a Neandertal ancestor six generations back,” he said, which meant a Neandertal great-great-great-great-grandparent. “But,” he continued, “it’s distributed differently in the genome, in small pieces everywhere. If it were a [direct] ancestor, it would be in big pieces.” Because these small pieces aren’t coming from direct ancestors but from distant ones whose genes have remained in us but get recombined in each generation. What this also means is that all of us carrying this 0.7 to 2.1 percent (to include Africans as well as Eurasians) have different pieces of the Neandertal genome within us. If we took all our little pieces and pooled them, then how much of the original Neandertal ancestors do we all collectively carry around within us today?
“It’s still a bit unclear,” Svante answered the Parisians regarding this very question, “but somewhere in the order of forty percent or so of the Neandertal genome still exists in people today.”
So, to Theodore’s point, had there been more admixture and total absorption of Neandertals into our modern populations, we would be seeing that 40 percent or so in one person, or at least more than the 1–2 percent on average that we do see in any one person.
“That’s probably because we were diverged biologically, that it couldn’t happen in part because of hybridization issues and fertility issues and other things.” Theodore finished his explanation. “So. We’re a bit Neandertal for the most part, and some of us also have a bit Denisovan admixture in there. But what is interesting is that there’s a persistence of the admixture, which suggests that it’s a part of the formation of the modern human populations in their dispersal over the world. And then, even though we share a lot with Neandertals, we also share a number of things that are different. The differences we have with the Neandertals, it’s not just the number of markers we have, it’s actually which genes and what form of those genes that we actually have.”
“What about the FOXP2 gene?” I asked to this theme. We carry the same version of it as is found in the Neandertal genome. It’s the so-called language gene, another recent hot topic, though more accurately, there are a few hundred areas on the human genome, unknown to date, that are involved in bringing about what we call human language. Or almost any other trait: If there are over 697 places on the human genome that work together to express a person’s height alone, imagine what complexities of many genes are involved in something seemingly more complex, such as language.
“The FOXP2 gene has an important role,” he said, “in the development of the areas of the brain related to language comprehension and production. There’s a unique form of this that was identified in humans that’s different than any other form found in apes, but it is present in Neandertals. It could be some kind of a hominin-type of thing, which would allow for some kind of communicative skills, abilities, language or proto-language, whatever you want to call that, in these earlier hominins.” Hominin refers to the collective of modern humans and all forms of extinct humans, including all lineages of Homo and extending even into earlier ancestors, such as the Australopithecines.
“But the form of language that we have now,” he elaborated, “our brain has also grown, we aren’t just looking for language areas in the brain; basically the whole brain is connected in some way, to symbolic work and so forth, but that’s a very important one, the FOXP2, because it has developmental implications.” If one copy of the gene is mutated, one copy of the two we each have, one from each of our parents, a person will have significant difficulties with language learning and communication.
ON ANOTHER LEVEL, we modern humans, those of us on the dig team at La Ferrassie, were merging, swapping, and admixing with Neandertals—not via our genes, or by making alchemical fire, though I suspect that went on too (I was blissfully oblivious, sleeping in la belle grange Chez Cécile)—but through our psyches. The psychic infiltration began deep into the second half of the dig season; everyone seemed to be reporting strange dreams, ones that showed the experience of camping and digging for a few weeks was altering us and had sunk into our subconscious minds.
Dennis was having those usual dig director dreams, but more vividly than the others: a lot of driving and logistics dreams, sorting out and troubleshooting all manner of issues, from finding Harold to getting everyone to the site. If he had any about Neandertals, he kept them to himself. But a crew member, Dafne, and I each had dreams that exposed our ideas about Neandertals and turned them into feature films.
One morning, she reported that she’d had a dream about visiting a medieval village, an archetypal one like the many villages that speckle the shores of the Vézère and Dordogne Rivers. She walked along cobbled streets, past stone homes, through winding village lanes where lots of tourists were visiting and eating at their outdoor cafés, consuming lots of truffle omelets, roasted duck, and perfectly poached foie gras, while sipping lots of local wine. In all this she walked until a crowd began to form around a man dressed in hides. Perhaps he had wandered in for the same reasons, to get a mouthful of the succulent fare offered up by his beloved Dordogne, but soon he was frightened by all the attention he received for looking different. The closer she drew, the more she realized he was Neandertal and no wonder all these modern types had frightened him. She woke up trying to catch up to him as he ran away. She wanted to help.
I had two dreams, both taking place at La Ferrassie. In one dream I was in the upper cave and looked down at myself and saw I was Neandertal, dressed in heavy furs but still cold. There were many others with me, a few adults and a few more children. We were cold and mildly hungry but had just managed to have something to eat before a huge storm blew in and snow swirled all about. Accurate to the record, my dream showed no fire. I heard a thundering outside and went to the edge of the upper cave’s mouth and looked outside and saw a towering mammoth, all white with long shaggy hair and tusks thick as his swinging trunk. He was lumbering toward us and crashed into the cave and everything tumbled and I woke up before, I think, I blacked out.
In my second dream, some days later, I was again in the upper cave but this time I was watching a female shaman holding a stretched-hide frame hand drum and beginning to beat it in order to alter her consciousness. She was doing a journey for a man who sat before her. We were all dressed in hides. Soon, a fourth person, a male shaman who was Neandertal, appeared and sat near the woman. She explained to me that to journey to the modern man’s past, she needed a Neandertal shaman to help because the modern man had been part Neandertal and the consciousness was organized differently.
I thought this was odd but soon found myself watching the two work together. The drumming began and I saw—saw as if someone were painting a graphic visual in the air above us—her “consciousness” take on the visual appearance of concentric circles like a round striated tunnel, a classic form reported by people who do drum journeys. Simultaneously, her male counterpart’s “consciousness” also appeared in graphics in the air above us, next to hers, and showed a different pattern.
His was an organic maze, no tunnel but a lot of folded-in passageways that rounded to and fro like folds of the brain. I watched the two forms in the air and felt two different kinds of electric pulses pass through my brain. Suddenly I was pulled into the maze pattern and found myself going deeper and deeper into the earth, landing in a chamber with dense crystal-like structures all around me and rectangular mosaics on the cave walls, also like crystal structures. The whole world was rust reds, ochre, and deep browns, like the different sediment layers at La Ferrassie. I looked down and saw a river of human bones.
That’s when I woke up.
I love dreams and strive to remember them and sometimes am rewarded with full Technicolor dreams. This one was of a different order. I sat up in Cécile’s childhood bed in my loft in the barn and wondered what I might have eaten, or drunk, the night before. Nothing that I could recall. It must have been the growing intensity of the dig season and how much time I spent thinking about Neandertals.
Just as the second half of the dig season was bringing up intense dreams, conversations during the lunch break were also riffing on more esoteric themes, almost as if it were safe now, this deep, to go into harder-to-chart territory. The waking and more rational sort of dream.
Harold and Shannon were talking about Neandertal and modern human behavior, mulling over the possibilities. They were riffing on a familiar theme, the different ways, it seemed, Neandertals and early modern humans went about solving their problems, that Neandertals worked out a unique solution each time and modern humans followed already established rules that made them think less and effect more conventional and commonly held ways to deal with something. Harold was uttering one of his favorite lines when I settled in.
“The Neandertal way requires a lot of smarts,” he said. “The modern human way of doing things, you don’t need to have as much smarts. Anybody can learn the rules.” And stop thinking too hard to solve something, limiting our creative solutions to those bound by the rules, not looking outside of them.
“Maybe rephrase that in a little different way,” Shannon said, ready to bring his usual calm counterpoint to some of Harold’s more brash statements. “Both folks are smart but the modern human ‘smarts’ is embedded in the culture. The culture is carrying that accumulative knowledge.”
Or what if Neandertal smarts weren’t so embedded in—or dependent on—cultural forms, I thought to myself, but more fluid, able to break cultural forms to conform to other norms such as the immediate environment and what was possible there? Modern humans were known to go well out of their way—waste a lot of energy in a sense—to get flint or hunt exactly the sort of animal they wanted to eat. It was a lot like people today who will drive out of their way to go to a grocery store that carries a special product rather than make do with what the local stores have in stock or alter the recipe to accommodate it.
“The Neandertals,” Shannon added, “were not all that concerned; they just wanted to get their stuff, figure out how to get it.” Without complicating it by adding new or further steps.
It was another way of getting at the same point Alain had made, that Neandertal adaptations seemed to have a more flexible—less rule-governed—intellectual approach that allowed them to solve each problem uniquely each time. Modern humans seemed, by contrast, to have a more rigid, culture-controlled, rule-governed intellectual approach that limited the solutions but assured that everyone agreed on what the options were and didn’t have to invent them each time.
“The Neandertal way to me is the smart way,” Harold said, popping a piece of cheese in his mouth and savoring it. “The trouble is, there’s a cost. If you’ve got a family that’s, you know, not playing with a full deck, well, you’re not going to figure things out all the way, all the time, and that’s going to put you at a disadvantage.”
“Well, it’s also not going to get you to the moon,” Shannon added. “The system of storing knowledge and passing it on has tremendous benefits in the long run.”
“That’s why you see a stasis for so long in the Middle Paleolithic,” Harold agreed. “There’s not much variability because it’s constantly reinvention, reinvention, reinvention. They have a repertoire in terms of technology that they can call on, but they’re not robots: It’s intelligent behavior. They’re actually figuring something out, appropriately. I would say that modern humans are more like robots: I get on a plane and I stay American the whole time. I get into France and I’m still American, whereas I picture more, well, this wouldn’t happen, but imagine it does: a Neandertal gets on an airplane to France; he’s going to see what the resources are and do it that way, the French way. Though,” Harold chuckled, “we’d probably both wind up wanting chocolatines.”
Shannon busted out laughing, as did Dennis, Vera, and Paul, who had been listening in on all of this. Beyond them, so had the crew and everyone was hungry again. Chocolatine is the local name for pain au chocolat, those crazy delicious buttery croissant creations that have a brick of dark chocolate baked in the center.
“And you’d still want vin de noix,” Shannon added with a straight face, mentioning the regional walnut wine.
“Exactly. Nothing wrong with that,” Harold replied. “But I’d take mine with ice.” Mad dogs and Englishmen! The French do not put ice in their vin de noix.
“Well,” Dennis entered the discussion, “you would eat the chocolatine and he would eat you with the chocolatine.”
The whole site erupted with even louder laughter.
“I’d make a nice dessert,” Harold defended, pretending to be miffed. “But to even say something like that,” he returned to the original part of the conversation, that Neandertals may have had a smarter adaptation than us, “nobody can get it. ‘Oh, you’re bashing the Neandertals now,’” he said sarcastically, “‘you’re calling them smart.’”
“What about the FOXP2 gene?” I asked. “Culture and language are very bound up together as symbolic products.”
“It just means capacity,” Dennis answered.
“Right,” Harold said, “capacity versus performance.”
“So, couldn’t you say then, that there was also the capacity and the foundation for symbolic thought?” I prodded.
“Of course,” Harold said. “But you’ve got to see the performance take place to conclude that they did it. I think that’s one of the big hangups here, all the time, is that people look at Neandertals and say, ‘Well, physically and brain-wise they’re so similar to us, they must have had a capacity.’ Everybody since the Magdalenian could have had the capacity to make spaceships. And in the Aurignacian, they had the capacity to play pianos,” added Harold, “but they did not.”
“Hey, hang on, hang on, hang on,” Shannon said. “If the Châtelperronian was made by Neandertals, then the deal is done.”
“Right,” Harold replied. “Then it shows by performance that they had the capacity.”
“Yeah. And you don’t even need genetics.”
“Exactly.” Harold popped another piece of cheese in his mouth and chomped with glee.
It was time to return to our respective trenches, inspired again as we worked hard and carefully to gather the material meticulously so somewhere down the road the experts could discern actual behaviors with evidence to back it up. But I also looked forward to Scotch Time, a tradition—rule-governed maybe, but adaptively flexible, especially because Harold was such a forthcoming and cheerful person—at which to ask more about this whole capacity-versus-performance thing.
As a cultural anthropologist, I got both from modern human culture, so I could test my theories just by hanging out in the field long enough. Not so in archaeology. You needed material evidence to show that the more abstract stuff happened.
Once we were back in Carsac, I rushed to Cécile’s for a quick shower and to report to her the dinner menu that evening: roasted pork, garlic-sautéed green beans and salsify, a special kind of white asparagus-like tuber found in the southwest, and buttered noodles.
“Tell Harold I’ll be there for dinner,” she said. This was our ritual. Harold reminded her all the time that she was always included in dinner, but she liked to take a very French approach and hear the daily menu, mull it over, and then decide to come over anyhow. The French love to talk about food, a wonderful cultural development.
Clean, back at Camp Dibble, the scotch chilled as ice crackled in our glasses, soda on the rocks for us both, very refreshing after a hot day in the sun—I asked Harold to elaborate on the lunchtime conversation.
“There are all sorts of different adaptations out there,” he said. “So when we talk about Neandertals as being a member of our species, it doesn’t mean they’re exactly like New Yorkers. It doesn’t mean they’re exactly like anything. They could have a kind of adaptation that doesn’t exist anymore on the planet. It’s still is a human adaptation. I think that we’re looking at human adaptations going way back, even beyond the time of Neandertals. So it’s a kind of human adaptation. But does it mean it’s ours?” He took a sip of the very fine liquid adaptation in his hand and paused to enjoy it.
“So okay,” he continued, “they’re the same species. They can still have different adaptations. Do they do things, then, exactly like we do them? I think they’re just as smart as we are—there’s hardly any way that you could argue the contrary. They’ve got brains as big as ours; they’re technologically savvy; they’re long-lived . . .”
“And looking at the way neuroscience understands the way the brain functions, there’s really no way to say that their brains were any different,” I added, swirling my glass as he did, the sound of ice against glass pleasing backup music to pontification.
“No, there’s no evidence.” He agreed.
“The brain is flexible, it’s plastic,” I added. I had been reading more in neurobiology to get a better understanding of the brain and was learning that it’s still largely a huge mystery but a very pliable one.
“Exactly,” Harold agreed again. “It’s hard to characterize brains. That’s why I say, look, they’ve got brains just as big as ours. They’re smart. They’re technologically savvy. They use technology, a complex technology. So, in that regard, they’re just like us. Then that leads to the question, okay, do they have other things that we have? Do they have language? Everybody wants to equate language with intelligence, right? But that’s saying, we’re intelligent, we have language, so that means, we’re intelligent, we have bipedalism. Does bipedalism make you intelligent? That’s dumb. They’re two independent things.”
“Those are just questions again to make them just like us,” I said as I picked up the scent of roasting meat and frying garlic wafting in through the open window from the backyard below. I took a sip. I loved this hominid life.
“That’s right,” he said. “When I say Neandertals are doing something differently, it’s not saying that they’re further down the line, that they’re stupid or anything like that. What I say is, ‘Oh, you know what, it looks like they are behaviorally different, so in what ways are they different?’ By looking at it that way, suddenly we’ve got a sample of two humans to compare. We’ve got us and we’ve got another that is very similar to us. Now what is the difference? Let’s get at the behavior and see what they were doing.”
Cécile arrived in the doorway, signaling it was almost time for dinner. She joined us for an aperitif and we shifted from brains to interior décor, she as ever trying to introduce more color into the dig house, not realizing that just by being there, she did.