Last Ape Standing: The Seven-Million-Year Story of How and Why We Survived (21 page)

It might have happened this way. But Europe and Asia are immense territories, and it’s difficult to imagine that there wouldn’t have been enough resources to go around. The Neanderthal range covered tens of thousands of square miles. Genetic studies indicate the entire Neanderthal populations rarely numbered more than seventy thousand people spread from the Iberian Peninsula and the south of England clear to the plains of western Asia beyond the Caspian Sea. While each band probably needed several square miles of land to sustain them, much of the land was rich with food and resources and herds of large animals from mammoths and woolly hippopotamuses to deer, bison, and aurochs.
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Even if the combined numbers of both Neanderthals and modern humans reached into the hundreds of thousands, there would seem to have been plenty of space, food, and resources, and much of Europe, even at the height of the last ice age, would have been temperate enough to accommodate any variety of human—Neanderthal or not. The frigid weather would certainly have battered Neanderthals trapped in cold areas, but why wouldn’t those already living in the more temperate climates of southern Italy, Spain, France, and the Mideast have survived?

Maybe because it was more complicated than any one of these scenarios. Maybe the mysterious people from the south brought new diseases or parasites with them or forced radical cultural changes that Neanderthals simply couldn’t adjust to. After all, white men from Europe destroyed the cultures and ways of an entire continent of native North Americans, scores of individual tribes numbering in the hundreds of thousands, and they did it inside of four hundred years. This
wasn’t simply a matter of brute slaughter. The blunt impact of a different kind of culture can also do considerable damage. Could immigrants from Africa have wreaked the same kind of havoc on the Neanderthal natives of Europe, except in this case taking twenty-five thousand rather than four hundred years? It’s possible.

Stephen Kuhn and Mary Stiner at the University of Arizona suspect that modern humans arrived in Europe with cultures that divided labor within their tribes in a way that was safer for pregnant women, mothers, and children by keeping them focused mostly on collecting vegetables, fruits, and nuts, while men concentrated on hunting large animals. Based on their research, Kuhn and Stiner believe Neanderthals divided their labor among the sexes differently or, more accurately, didn’t divide it at all. Men and women both undertook the deadly work of bringing down big game, and that meant that women who were killed in hunts would not survive to bear more children. The teens and adolescents lost in hunts would further have depleted the clan.

Though the Cro–Magnon approach to dividing labor didn’t mean they attacked Neanderthals, it would have had an impact nevertheless because eventually more Cro–Magnon women would have survived to bear more children than their Neanderthal counterparts, growing their population while Neanderthals struggled to keep pace with replacing the members they were losing. Even if the Neanderthal people were tougher, over thousands of years the competitive difference could have completely rearranged the population balance, just as divergent social approaches shifted the balance between whites and Native Americans.

This may help explain why the Neanderthal population never really took off, even when ice ages relented. Their mortality rate was simply too high, and they were spread out too thinly. It may also help explain why their culture and technology remained doggedly unchanged for two hundred millennia. It’s terribly difficult, even within a clan, to pass along new ideas and innovations when members rarely lived past thirty or thirty–five years, and others are being wiped out in the prime of their childbearing years. Who knows how many Neanderthal Galileos or Einsteins died suddenly in the hunt and took their genius and inventions to the grave with them? It’s nearly impossible to build anything but the most rudimentary traditions when innovation is rare and life passes so quickly. In this scenario, the Neanderthal found
themselves fighting, millennia after millennia, a pulverizing war of attrition. In the end, extinction was the only possible outcome.

One last theory about the demise of Neanderthals is particularly tantalizing: If we killed them at all, we killed them with kindness. We neither murdered them nor outcompeted them. We mated with them and, in time, simply folded them into our species until they disappeared, reuniting the two branches of the human family that had parted ways in Africa two hundred and fifty thousand years earlier when small groups of restive
Homo heidelbergensis
headed across North Africa and into Europe.

It’s fascinating to consider the possibility that we and another kind of human together bred a new version of the species. Whether this happened was, only a few years ago, one of the great controversies in paleoanthropology. But now there is persuasive evidence that something like it did.

In 1952 the remains of an adult woman were found lying on the floor of the Pestera Muierii cave in Romania—a leg bone, a cranium, a shoulder blade, and a few other fragments. The people who discovered these bones didn’t think much of them. How old could they be, after all, if they were simply lying there on the ground for anyone to kick around? As a result, soon after their discovery they were squirreled away in a researcher’s drawer where for more than half a century they lay undisturbed and forgotten. Eventually, however, a team of scientists that included Erik Trinkaus at Washington University in the United States and two Romanian anthropologists, Andrei Soficaru and Adrian Dobos, rediscovered the bones and gave them a closer look, and when they did, they were stunned. Radiocarbon dating revealed the woman hadn’t lived recently at all, but last walked Earth thirty thousand years ago. The other startling discovery was that the fossils exhibited features that were clearly Cro–Magnon–like, but also distinctly Neanderthal. The back of the woman’s head, for example, protruded with an occipital bun, a distinct Neanderthal trait. Her chin was also larger and her brow more sloped than a modern human’s. The woman’s shoulder blade was narrow, not as broad as a modern human’s. Was she simply a rugged–looking modern human, or, as one scientist wryly put it, proof that moderns “were up to no good with Neanderthal women behind boulders on the tundra?”

Other similar finds made recently throughout Europe keep boggling the minds of scientists who study this question. In another cave in France researchers have unearthed not bones, but tools that date back thirty–five thousand years. Their location indicates that for at least a full millennium both Cro–Magnon and Neanderthals coexisted in this place. If they could live together, and if they could communicate and cooperate, isn’t it likely that at least a few crossed the species line and, in a prehistoric foreshadowing of Romeo and Juliet, mated?

Then there is the mysterious skeleton of a young boy unearthed in Portugal that is 24,500 years old. While conventional wisdom has it that the last Neanderthals died out thirty thousand years ago, the large size of this boy’s jaw and front teeth, his foreshortened legs, and broad chest have caused Trinkaus and others to wonder if he, too, might not be a hybrid. Though his chin is Neanderthal in size, it is also square, more like ours, and his lower arms were shorter and smaller than you might expect if he were
Homo sapiens
.

Strangely enough, this part of Portugal is among the last places in Europe where Neanderthals lived before they disappear from the fossil record. Was this boy simply among the last of his kind, archaeological proof that Neanderthals were finally and inevitably swallowed, genetically or otherwise, into the rising tide of modern humans spreading across the planet?

Until recently, the only evidences of interbreeding were perplexing finds like these, smoking guns that indicated we and Neanderthals had mated, but nothing irrefutable. Then in 2010 a scientific consortium headed by the Max Planck Institute for Evolutionary Anthropology completed its historic analysis of the Neanderthal genome, accomplishing for our burly cousin species what we had done for our ourselves seven years earlier. The analyzed DNA was extracted from three Neanderthal bones discovered at the Vindija Cave in Croatia not far from the Adriatic seacoast. To decipher the tantalizing possibility that we and Neanderthals may have produced common offspring in the deep past, the team compared the Neanderthal DNA with the genomes of five people of different lineages from around the world—French, Han Chinese, Papuans from New Guinea, and the Yoruba and San people of Africa. The San are, genetically, very close to the first modern humans to have evolved in Africa.

What dumbfounded the project’s investigators, and the rest of the scientific world, was that all the genetic samples taken, except for the
Yoruba and San people of Africa, contained 1 to 4 percent Neanderthal DNA. In other words, most of the human race from Europe to the islands of Southeast Asia (and probably farther) is part Neanderthal! That Africans seem not to share any Neanderthal blood indicates that these two families mated after the wave of
Homo sapiens
departed Africa, but before their descendants headed into Europe and Asia. According to the researchers, this would have been somewhere between eighty thousand and fifty thousand years ago.

Was that the only time modern humans and Neanderthals bred? The research team isn’t saying, but right now they can only base their conclusions on the research in hand. This will disappoint those who believe that Neanderthals and modern humans melded during those twenty-five thousand years of cohabitation in Europe into a single species whose recombined genes, shaped by separate evolutionary pressures, created a new kind of human. But it doesn’t rule the possibility out. There simply isn’t enough information on the scientific table right now to say.

That we mated still doesn’t conclusively solve the mystery of how the hardy, quiet people of the North met their end. Was it murder, competition, or love? Does it have to be one or the other? Nature, evolution, and human relations are all chaotic and unpredictable, as much as we might like them otherwise. When Europeans colonized North and South America, they sometimes befriended the natives, sometimes brutally exterminated them, sometimes raped their women, and sometimes fell in love and raised families. Were Neanderthals so different from Cro–Magnon that sex was out of the question? If the Max Planck findings are accurate, clearly not. Both species were human, and the drive to procreate is strong and primal. Humans, after all, have been known to have sex with other primates, even other animals. Surely both species found enough common ground over twenty-five thousand years to bed down together during those frigid European winters. One of the inescapable lessons of evolution is, if anything can happen, it probably will.

Whatever ultimately transpired between our two species, events eventually rendered Neanderthals first endangered and finally extinct. For two hundred thousand years they were punished by a cold climate that kept their numbers small and made it difficult to develop stable trade, and to share and amplify the advances of their scattered
clan cultures. Even with complex forms of communication, no matter how different from ours, they would have been hard–pressed to build a broad and increasingly sophisticated culture. They seem to have had their work cut out for them simply maintaining the status quo. So, in time, they disappeared, presumably one band at a time. Sometimes, perhaps, at the hands of one another. Sometimes to disease or famine. Sometimes to climate change, undoubtedly a particularly destructive culprit, especially if their technologies couldn’t keep up as modern humans began to usurp their favorite places to live, killing game before they could and depleting limited resources.

Sometimes the Neanderthal may have battled for those places and lost or moved on, as Native Americans did until nothing but the poorest lands were left upon which to scrape out a life. Or sometimes they may have compromised and cooperated and befriended their clever, slim competitors, until there was no difference between the two, and they had disappeared into the gene pool of their cousin species, leaving a few bones and tools and a bit of their DNA in us as a legacy of their more prosperous days on earth.

Precisely how the end came is impossible to say, but inevitably, somewhere, sometime, the last Neanderthal passed from this earth. Current theories hold that surviving bands may have retreated south during the last ice age to the Iberian Peninsula, holing up on Gibraltar, a last outpost at the toe of Western Europe.

Gibraltar protrudes like a great snaggled tooth from the southern tip of Spain no more than fourteen miles from the north–facing coast of Africa. For one hundred thousand years Neanderthals had been revisiting and living in a great cave, today known as Gorham’s, that sits at the base of the peninsula’s massive promontory rocks as they hover hawklike over the Mediterranean. If the radiocarbon dating of nuggets of charcoal found in the cave is accurate, the Neanderthal stoked their last fires here twenty-four thousand years ago, much more recently than scientists once thought possible.

Gibraltar was different during the last ice age than it is today. Populated with deer and ibex and rabbits in the craggy hills above the cave’s colossal and vaulted ceilings, it made a perfect refuge for a vanishing species. With sea level in the Strait of Gibraltar 240 to 360 feet lower than it is today, the cave would have gazed like a cyclopean eye on sprawling plains and marshlands that stretched west across the great bay rather than the blue sea that surround the land now.

The bones left behind tell us the cave dwellers dined sumptuously on tortoises, fish, and other marine life. It had long been a good place to be, and now, it seems, it was the
last
place to be. For the Neanderthal, only Africa itself could take them farther south. To the north the Cro–Magnon had been moving into their territory for millennia, and beginning six thousand years earlier the climate had grown fiercely colder, driving clans south until finally only this one last settlement remained, clinging to the underbelly of the continent.