Interesting. Teasing apart the many factors that play a role in the extinction of the Neanderthals is exceedingly difficult. Decades ago, it was assumed that the Neanderthals were intellectually and technologically inferior to modern humans, and simply could not compete. However, recent discoveries demonstrated that the Neanderthals had art, tools, and shelters. They probably had language. Their brains were larger than that of modern humans.  They were much stronger.<p>Some scientists speculate that the Neanderthals could not adapt to the changing climate as the ice age receded, whereas modern humans from Africa were are better adapted to warmer climates.<p>I doubt that. The Neanderthals spent 200,000 years in Northern Europe, Southern Europe, the Middle East, and parts of Asia; surely they were quite adaptable, to have survived that long.<p>I suspect that the reason the Neanderthals died out is that modern humans were more aggressive, more murderous, more apt to kill the other.  Modern humans developed in the brutal savannas and jungles of Africa, and when they came north, they brought their brutal ways with them.  When they encountered Neanderthals, they probably killed the men and enslaved some of the women.  Eventually, the Neanderthal population dropped so low that it was no longer sustainable as a separate species.