“Some Neanderthal populations died out, some got massacred, some interacted [with humans] and some only exchanged ideas.”
— Sang-Hee Lee, biological anthropologist at the University of California.
What caused our hominid cousins, the Neanderthals, to die out some 36,000 years ago? Ever since the first skeleton was discovered by quarrymen in Germany’s Neander Valley in 1856, Neanderthals have been the subject of wild speculation, particularly the manner of their extinction: Why did we survive when they didn’t?
Recent research (found under such clickbait headlines as, “Were Neanderthals Lonely?”) centers around the possibility that there were just too few of them and that they lived in small, isolated groups, resulting in inbreeding. When a breeding population is small and insufficiently diverse, harmful mutations aren’t automatically filtered out. Which doesn’t seem to have been the case for contemporaneous human populations, who interbred regularly, according to DNA analysis of ancient skeletons.
Before discussing the latest findings, let’s look at some other extinction possibilities.
Violence: Neanderthal vs. Neanderthal and/or Neanderthal vs. human conflicts in the search for scarce resources during times of harsh climate conditions may have whittled down Neanderthal populations.
Diseases: When humans first encountered Neanderthals in Europe some 50,000 years ago (a date much debated), the latter may have been decimated by tropical pathogens carried by humans who had more recently left Africa, and therefore had developed immunity. The modern parallel is, of course, Europeans infecting Native Americans with smallpox, measles and other diseases.
Lesser toolmaking and hunting abilities: Neanderthals were smart (and unworthy of modern insults such as, “Oh, he’s just a Neanderthal”). For instance, most paleontologists agree that they wove simple blankets and ponchos, used fire for cooking and warmth, and were familiar with medicinal plants. (The jury is out whether they had language. They were probably capable of it, since, according to recent research on Neanderthal skeletons, they had virtually the same capacity as humans to both produce and hear speech.)
That said, they probably weren’t as smart or adaptable as the humans with whom they shared the land. Although the brain of a typical Neanderthal was larger than the typical human living in the same region, its parietal lobes and cerebellum — the areas of the brain affecting tool use, vision and creativity — were smaller. In his book The Third Chimpanzee, paleontologist Jared Diamond pitches this “competitive replacement” theory. As evidence, he cites historical examples of what happened when people with advanced technology (e.g. guns) clashed with people with less developed technology (e.g. spears).
Back to inbreeding. A newly discovered (2015) Neanderthal skeleton dubbed “Thorin” (after the dwarf leader Thorin Oakenshield in The Hobbit) who lived around 42,000 years ago in the Rhône River valley of Southern France has reinforced the inbreeding hypothesis. DNA recovered from Thorin’s teeth and jaws shows that he was a member of a group genetically distinct from other nearby Neanderthal populations. For some 50,000 years, Thorin’s tribe and other Neanderthals living about 100 miles away failed to “exchange genes,” as one researcher delicately put it. “They coexisted while completely ignoring each other … unimaginable for a Sapiens [modern human],” according to Ludovic Slimak of the University of Toulouse.
One way or another, Neanderthals died out. But not before they, um, exchanged genes with those of our species who had migrated out of Africa. So, if you’re descended from white Europeans, the resulting hybrid species — perhaps 97 percent human genes and 3 percent Neanderthal genes — is the one to which you belong.
Barry Evans (he/him, barryevans9@yahoo.com) wonders what sort of world we’d be living in if we Neanderthals were still living among us today.
This article appears in Why California Housing Costs are So High.