Sometimes survival of the fittest is survival of the weakest:
About 30,000 years ago, the vast forests of Eurasia began to retreat, leaving treeless steppes and tundra and forcing forest animals to disperse over vast distances. Because they evolved in the warm climate of Africa before spreading into Europe, modern humans had a body like marathon runners, adapted to track prey over such distances. But Neanderthals were built like wrestlers. That was great for ambush hunting, which they practiced in the once ubiquitous forests, but a handicap on the steppes, where endurance mattered more. This is the luck part: the open, African type of terrain in which modern humans evolved their less-muscled, more-slender body type “subsequently expanded so greatly” in Europe, writes Finlayson. And that was “pure chance.”Because Neanderthals were not adept at tracking herds on the tundra, they had to retreat with the receding woodlands. They made their last stand where pockets of woodland survived, including in a cave in the Rock of Gibraltar. There, Finlayson and colleagues discovered in 2005, Neanderthals held on at least 2,000 years later than anywhere else before going extinct, victims of bad luck more than any evolutionary failings, let alone any inherent superiority of their successors.
(Hat tip to Tyler Cowen.)