Roaming Romania 40,000 years ago was a modern human with a family tree that recently surprised scientists. Researchers figured out that this fellow could have had a great-great-grandparent that was a Neanderthal. In fact, genomic sequencing of the ancient jawbone specimen indicated that six to nine percent of the man’s DNA was Neanderthal. That’s the most Neanderthal DNA found in a modern human yet, says David Reich, professor of genetics at Harvard Medical School and an author of the paper about the findings, published this week in Nature
. Reich explains what this discovery helps us understand about the early interactions between Neanderthals and modern humans in Europe.