WASHINGTON — A 40,000-year-old skull found in a Romanian cave shows traits of both modern humans and Neanderthals and might prove the two interbred, researchers reported on Monday. If the findings are confirmed, the skull would represent the oldest modern human remains yet found in Europe. The study, published in the Proceedings of the National Academy of Sciences, will add to the debate over whether modern Homo sapiens simply killed off their Neanderthal cousins, or had some intimate interactions with them first. DNA samples taken from Neanderthal bones suggest there was no mixing, or at least that any Neanderthal genetic contribution did not make it to the modern DNA pool. But Erik Trinkaus of Washington University in St. Louis has in the past found bones that he believes show both modern human and Neanderthal traits, and now he and colleagues have found a skull. The skull, probably that of a teenager, has been dated to 40,000 years ago and shows many modern traits. But it also is a little flatter than most modern Homo sapiens, and exceptionally large upper molars more associated with Neanderthals. ‘Such differences raise important questions about the evolutionary history of […]