Humans didn't breed with Neanderthals

Posted by Emma Woollacott

Just as we were all getting used to being part-Neanderthal, Cambridge University scientists say we might not be, after all.

Research over the last two years has appeared to indicate that humans interbred with Neanderthals deep in the past, leaving traces of their DNA within us.

But a new study indicates that it's common ancestry, not hybridisation, that best explains the average one-to-four per cent DNA that those of European and Asian descent share with Neanderthals. 

"Our work shows clearly that the patterns currently seen in the Neanderthal genome are not exceptional, and are in line with our expectations of what we would see without hybridisation," says the university's Dr Andrea Manica.


Neanderthals and modern humans share a common ancestor who is thought to have spanned Africa and Europe about half a million years ago.

About 350-300 thousand years ago, though, the two populations became separated. The Europeans evolved into Neanderthals, and the Africans into modern humans.

However, as today, populations wouldn't have been completely mixed across continents: closer populations would have been more genetically similar to each other than those further apart. And because of this, the amount of ancestral DNA shared with Neanderthals would vary.

By examining the different genetic makeup among modern human populations, the scientists attempted to quantify this variation. They simulated a large number of populations representing Africa and Eurasia over the last half-million years, and estimated how much similarity would be expected between a random Neanderthal individual and modern humans in Africa and Eurasia. The resuts were pretty much what we see today.

