Neanderthal extinction

(See also Neanderthal language.)

Why did the Neanderthals die out while modern humans survived? Paleontologists have made a lot of suggestions about why Homo sapiens survived and Homo neanderthalensis died out, but I have an idea that I haven’t seen elsewhere.

The two species overlapped in time, and in Europe for over 10,000 years also in geographic range. Neanderthals had slightly larger brain cases, which may mean that an individual Neanderthal was smarter than an individual Cro-Magnon. Pay no attention to self-aggrandizing stereotypes. When Cro-Magnons first appeared, Neanderthals had more advanced stone tools. But somehow Cro-Magnon cultures advanced more rapidly, and eventually the Neanderthals must have been outcompeted. Why?

Neanderthals were specialized to hunt large prey. Their restricted range suggests that they must have had trouble exploiting other food sources (they lived through the ice age, so they were surely tough and adaptable to different environments). Cro-Magnons were more generalized and migrated to live across a much wider area. My explanation is that the Cro-Magnons simply had a larger population and, whether it was because they lived in larger tribes or because of wider trade contacts, were therefore able to innovate faster and retain a higher overall level of expertise.

Of course it’s only one theory. It’s just as likely that Neanderthals didn’t want to have new ideas, or that lower food requirements for the smaller and weaker Cro-Magnons made the difference in the long run, or any of many other ideas that have been suggested. But there is scientific evidence that it takes a larger population (at least of modern humans) to maintain a more advanced culture.

2014 update

Wow, sometimes science moves fast. Some points above are now clearly mistaken, while some may still be ok. Neanderthals apparently did not have a much different diet than “anatomically modern humans”, so they probably weren’t in fact specialized to hunt large prey, at least not more than you and I are. But according to the study “Patterns of coding variation in the complete exomes of three Neandertals” by et al (almost as many authors as a particle physics paper), Neanderthals do appear to have had smaller and more isolated population groups. (I was expecting that conclusion, so I’m predisposed to accept it.)

The big obvious difference between Neanderthals and modern humans is robustness. Neanderthals had bigger and stronger bones, and no doubt bigger and stronger muscles. Chimpanzees do too, adjusted for body weight; in a hand-to-hand fight against a chimpanzee, I don’t think it matters if you practice Krav Maga, I think you lose, period. All the evidence I’ve seen is consistent with the theory that modern humans outcompeted other ancient humans because of a larger population, and that the larger population came about because we are weaker. We had to substitute brains for brawn, and we needed less food to get by, both of which suggest a larger community size. If so, then we are the ants of the ape world, shifting to cooperation and group adaptability over individual ability. And like ants we have spread.

Updated April 2014.
Original version, December 2010. Added here November 2011.