Just how did Neanderthal men and women became extinct? It’s a matter of fascinating debate. Were we smarter than them? More warlike? Or perhaps we simply sexed them into extinction? The real answer might have more to do with our quantity than our qualities. For about 300,000 years, Europe was pretty much the undisputed domain of the Neanderthals. About 60,000 years ago, modern humans entered the continent, and by 40,000 years ago, the Neanderthals were gone forever. It’s difficult to figure out just what caused this extinction – and it’s almost certain that multiple factors were in play – but Cambridge researchers now think they’ve hit upon the primary reason why Neanderthals died out: there simply weren’t enough of them to compete. Video here