"Modern European and Asian people may owe more than skin or hair colour to ancestry. 50,000 years ago between two species of human may also have bequeathed a sunburn hazard called , to , and a greater risk of . That the forebears of modern ‘’’’ and the long-extinct Neanderthals lived side by side is well known: that they interbred, and that up to 4% of modern human DNA is inherited from the first Europeans, was confirmed only in 2010."