DNA paints a contested picture of Stone Age interbreeding
2012 SCIENCE NEWS TOP 25: 14
The scientific paparazzi who followed long-gone evolutionary celebrities this year exposed plenty of hanky-panky between early humans and closely related species. These new findings (inexplicably ignored by supermarket tabloids) raise questions about how much genetic swapping happened in the Homo genus tens of thousands of years ago. What’s more, the mixed-up family tree is uprooting the popular view that modern humans evolved in Africa and spread from there, edging out close relatives such as Neandertals.
In one revealing report, an international team unveiled a largely complete genetic library extracted from the finger fossil of a Stone Age girl (SN: 9/22/12, p. 5). Her DNA suggests that she came from a small Siberian population — called Denisovans — that moved through East Asia tens of thousands of year