One scientist thinks he know why the Neanderthals went extinct: We ate them.
A team led by Fernando Rozzi, of France's National Center for Scientific Research, re-examined modern human bones found in a cave near Les Rois in southwestern France and found that one jawbone was instead Neanderthal.
Crucially, it was covered in cut marks, indicated it had been butchered. The human bones were untouched.
"For years, people have tried to hide away from the evidence of cannibalism, but I think we have to accept it took place," Rozzi told London's Guardian newspaper.
Neanderthals were a closely related human species that evolved 300,000 years ago in Europe and the Middle East, but went extinct about 30,000 years ago, soon after modern humans moved into those areas.
They were shorter and stockier than we are, with heavier brow ridges and weaker chins. Though they had larger brains, evidence suggests they might not have been capable of speech.
"This does not prove we systematically eradicated the Neanderthals or that we regularly ate their flesh," Chris Stringer of London's Natural History Museum told the Guardian. "But it does add to the evidence that competition from modern humans probably contributed to Neanderthal extinction."