Ancient humans may not have interbred with Neanderthals, after all

If you hail from outside of Africa, there's a decent chance that you share as much as 4% of your DNA with a long-extinct lineage of Neanderthals. Many scientists agree that this small percentage of shared genetic information is evidence that humans and Neanderthals interbred with one another in Europe tens of… »8/14/12 10:20am8/14/12 10:20am