THEY are often depicted as dim-witted evolutionary losers, but Neanderthals were not driven to extinction by their lack of brains, a new study suggests.
Instead, it is more likely that they disappeared 40,000 years ago due to interbreeding and assimilation with early human ancestors, scientists believe.
An analysis of archaeological evidence dating back 200,000 years reveals they were more advanced and sophisticated than has widely been thought.
The differences between the two human sub-species are not enough on their own to account for the demise of Neanderthals, say the two US and Dutch researchers.
Dr Paola Villa, from the University of Colorado Museum, and Professor Wil Roebroeks, from Leiden University, wrote in the online journal 'Public Library of Science ONE': "Genetic studies now suggest the debate on the demise of the Neanderthals needs to be reframed in terms of some degree of interbreeding.
"In that sense, Neanderthals did not go extinct, even though their distinctive morphology did disappear.
"We conclude that all the 'archaeology-based' explanations for the demise of the Neanderthals . . . are flawed."
Neanderthals thrived in Eurasia for 300,000 years but vanished around 40,000 years ago as early modern humans began to settle in Europe.
In the past, experts have theorised that Neanderthals died out because they were mentally, technologically and culturally inferior to the newcomers.
But more recent evidence has shown that Neanderthals made effective tools and weapons.
Neanderthal DNA, which was sequenced in 2010, shows clear evidence of interbreeding, the researchers add. Neanderthals and early modern humans are most likely to have interbred in Europe and the Middle East around 50,000 years ago.
The scientists say they were not so much driven to extinction as assimilated.
Some human-like characteristics have been found in late Neanderthal fossils, and conversely, Neanderthal features were seen in early specimens of modern humans in Europe.