'More Neanderthal than human': How your health may depend on DNA from our long-lost ancestors livescience.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from livescience.com Daily Mail and Mail on Sunday newspapers.
Nearly half of Europeans died from the plague. Now a new study shows a protective gene mutation that survivors passed on to help with future outbreaks might cause other problems.