The Humans Who Went Extinct: Why Neanderthals died out and we survived.
By Clive Finlayson.
The prevailing dogma in paleontology has it that Neanderthals were less intelligent, or at least less adaptable than our own ancestors, and that’s why they are gone and we are still here. We replaced them; perhaps we killed them--maybe even killed them and ate them. Or perhaps they simply could not compete once our ancestors had entered the game. And of course, since we are the survivors, we must be superior. So the only question remaining is what makes us so wonderful and how did we get that way. (A recent NOVA program, The Spark of the Human, consisted of modern humans asking other modern humans just what makes us so wonderful.)
As comforting as we may find such an analysis, it is probably not the whole story. And about a decade ago, Dr. Clive Finlayson began to suspect that it may not be true at all. Dr. Finlayson is an evolutionary ecologist with a DPhil from Oxford. He is the director of the Gibraltar Museum and adjunct professor at the University of Toronto. His work has focused on Pleistocene caves in Gibraltar, and his specialty also has been the study of climate change and its effect on the survival of bird species.
When Dr. Finlayson began to have doubts about the conventional views on Neanderthal extinction, he asked just how much evidence supports these views, and discovered that there was little or none. Scientists had merely assumed that since the Neanderthals are gone and we are still here, we must be in some way superior. But this raises some awkward questions, such as, why did Modern Humans reach Australia 15,000 years before they entered Europe, unless the Neanderthals were keeping them out. And if the Neanderthals were able to keep us out, then that would indicate our inferiority, not theirs. And if they were able to survive for over 300,000 years in Europe and in Siberia, though extremely challenging climate conditions, how could they be so inferior?
Dr. Finlayson takes the view that the course of evolution is shaped by random events, mostly climate change. Continents move, mountains grow, ice caps come and go, sea levels rise and fall, and land masses become wetter or dryer. Whenever a radical climate change occurs, many species go extinct, to be replaced by successful new species. Finlayson says that all of the many types of humans which at one time simultaneously existed (Modern Humans, Neanderthals, Hobbits, Late Homo Erectus, and who knows how many others) were all examples of relatively new species exploiting fairly recent climate changes. And except for us, all these species eventually went extinct, which is normal. But there are always a few species which survive the changes without going extinct—and these are the lucky ones, not the superior ones. He presents the case that survival is mostly a matter of being in the right place at the right time. Our ancestors were in the right place at the right time—and the Neanderthals weren’t.
Species are shaped by their environment. A lucky species is one that is shaped by its present environment, either genetically or culturally, in ways that also happen to work perfectly well in its next environment. This does not happen often, but when it does happen it is pure luck, and it’s what happened to us. The Neanderthals were not that lucky.
It has been argued that the Neanderthals perished because they lacked adaptability, but this is doubtful. The last known population lived in a cave at Gibraltar about 24,000 BCE. Although Europe was very cold at that time, Gibraltar was about as warm and wet as it is today, and the area was host to about the same plants and animals. The bones unearthed in this cave show that these Neanderthals hunted both small and large mammals, ate 145 species of birds, collected birds’ eggs, took shellfish from the beach, caught fish, ate tortoises, ate small reptiles, monk seals, and two species of dolphins. They were very opportunistic general purpose foragers. Modern humans who occupied the same cave four thousand years later left about the same array of animal bones, and even built their hearth in the same spot in the cave. They made their living about the same way that Neanderthals had. Finlayson says this shows that the variety of food sources which a population depends on is determined by what’s available—not how adaptable they are.
Neanderthals had never been mammoth hunters or reindeer hunters. These are fauna of the steppe tundra, and no part of Eurasia was ever steppe tundra at the same time that Neanderthals were living there. Neanderthals practiced ambush hunting, which requires a good thrusting spear, strength, courage, and cover. There is an abundance of edible animals on the steppe tundra, but no cover—just a vast treeless wasteland. This land would have grass and lichens beneath the snow for any grazing animal able to paw through the snow to get it. But these animals could only be killed if attacked from a distance.
The Neanderthals never lived on the steppe. They always lived in the band of woodland just south of the steppe, and they killed mostly red deer because that’s what was there. As the climate turned colder, couldn’t the Neanderthals have modified their technology so as to make throwing spears, and either bows or throwing sticks? Actually, they were probably experimenting in that direction. At one point, a “transitional technology” the Chatelperronian, began to appear in Europe. Earlier it was thought that these tools were made by modern humans. But the fact is, we have no idea who made them. It may have been the Neanderthals, or moderns, or both. But whoever made them died anyway. While the general trend of the temperature in Europe was downward, there were variations in both directions superimposed on this pattern. Often, a particular region would go from woodland to treeless steppe tundra in less than 150 years, and then go back to woodland in another 150 years. Any change of technology made for hunting reindeer would become useless when the reindeer were gone and the woodland deer were back. And a throwing spear is useless in heavy brush. Europeans were subjected not only to a cooler and dryer climate, but to rapid, random changes, which makes any kind of adaptation nearly impossible.
Eventually Europe was depopulated of nearly all humans, both Neanderthal and whatever moderns may also have been there, except for tiny populations clinging to small refuge areas in southern Iberia, Italy, and the Balkans. Then Europe was repopulated by people who could not only survive on the steppe tundra, but who had learned thrive there. But they did not learn to do this in Europe. These immigrants did not come up from the south—they came in from the east—from central Asia. And that’s where they learned to live on the treeless frozen waste. These people happened to be modern Homo sapiens.
Why was a central Asian population able to adapt to the new environment, whereas no humans in Europe had been able to do so? Because in central Asia, the climate change had been slow and gradual, and consistent. Eventually, the treeless, frozen steppe extended from France to Siberia, a thousand kilometers wide. The central Asians had been living on the edge of the tundra for a long time, and eventually learned to survive there. Then they simply expanded their range in every direction—west to Europe, northeast to Siberia, and eventually to the new world.
The Central Asians, our ancestors, were in the right place at the right time. The Neanderthals and any modern humans who were in Europe along with them, were in the wrong place. The author says that often a population living on the margins of the core area of their species will experience certain unfavorable climate conditions and have a chance to adapt to them, long before such conditions become widespread and engulf the whole core area. Those in the core area are wiped out, but those out on the margins, who have always had to deal with these climate difficulties survive. He cites as an example the population of nineteenth century Gibraltar. The Island has very little fresh water. The upper classes owned cisterns for storing rainwater, and a few had wells, but the poor had neither. In normal times, the rich had a much lower infant mortality rate than the poor. But in times of extreme drought, the poor, who had always drunk contaminated water, got on about as they always had, while the rich died like flies. The author calls this “the survival of the weakest.”
Did Neanderthals interbreed with modern humans? Recent DNA studies, published since this book was written claim that all modern humans from outside Africa carry between 1% and 4% Neanderthal DNA. Findlayson guessed that there was probably some interbreeding, but not enough so that modern humans carried very much Neanderthal DNA. He says that the problem was that the main group of moderns who would have had access to Neanderthals died along with them. The central Asian moderns all moved in after there were no more Neanderthals present, nor any moderns who had ever interbred with Neanderthals. The interbreeding probably occurred in the Middle East, just after our ancestors left Africa, because the DNA trace is found in all non African humans.
The Neanderthals were not dumb brutes. They used fire, they made tools, they buried their dead, in fact, when burying children, the graves were often strewn with flowers. They apparently did not use jewelry, but neither do I. I’ve never seen the point of body ornaments. But does my lack of jewelry make me intellectually inferior to someone who would prefer to wear a bone in his nose? Neanderthals were very much like us. They had the same range of hair coloring, including red hair. Red hair indicates fair skin, which would be required to make vitamin D in cold high latitudes. They had the same version of the FOXp2 gene as we have. This gene is involved in the development of the brain structures which process language. Modern humans with a defective FOXp2 gene can speak but cannot process syntax. The fact that we and Neanderthals share this same gene indicates not only that Neanderthals could speak, but that our common ancestor, Homo Heidelbergensis, could also speak.
Is there any way at all in which we moderns are superior to Neanderthals? Well, there is no way to be certain, but we might just have a superior ability to take credit for events we had nothing to do with.
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