As modern humans spread across Europe tens of thousands of years ago, they may have interbred with Neanderthals, creating hybrids, according to a new study of ancient human bones from Romania. Anthropologists have long wondered what happened when the two species met as modern humans spread from Africa into Neanderthal territory in Eurasia: did the populations interbreed or did modern humans simply replace their cousins? The specimens examined and dated for the first time in this study show that ‘at least in Europe, the populations blended,’ said study author Erik Trinkaus of Washington University. The study compared the fragments, including a skull [image] and jaw [image], to bones of Neanderthals, early modern humans in Africa before they spread, and in Europe afterward. Trinkaus said that he and his colleagues found certain features that could have only come from Neanderthals, because early modern humans lost them before they spread from Africa. They found a swelling at the back of skull, called an occipital bun, which is the result of differential brain growth and is commonly found in Neanderthal skulls. Also, the arrangement of muscle attachment at the back of the jaw was a trait of Neanderthals. […]