Neanderthals' large eyes 'caused their demise'

Neanderthals are a closely related species of human that lived in Europe
 from around 250,000 years ago.

A study of Neanderthal skulls suggests that they became extinct because they had larger eyes than our species.

As a result, more of their brains were devoted to seeing in the long, dark nights in Europe, at the expense of high-level processing.

By contrast, the larger frontal brain regions of Homo sapiens led to the fashioning of warmer clothes and the development larger social networks.

The study is published in Proceedings of the Royal Society B.

Neanderthals are a closely related species of human that lived in Europe from around 250,000 years ago. They coexisted and interacted briefly with our species until they went extinct about 28,000 years ago, in part due to an ice age.

Neanderthals

The research team explored the idea that the ancestor of Neanderthals left Africa and had to adapt to the longer, darker nights and murkier days of Europe. The result was that Neanderthals evolved larger eyes and a much larger visual processing area at the backs of their brains.

The humans that stayed in Africa, on the other hand, continued to enjoy bright and beautiful days and so had no need for such an adaption. Instead, these people, our ancestors, evolved their frontal lobes, associated with higher-level thinking, before they spread across the globe.

Eiluned Pearce of Oxford University decided to check this theory. She compared the skulls of 32 Homo sapiens and 13 Neanderthals.

Ms Pearce found that Neanderthals had significantly larger eye sockets - by an average of 6mm from top to bottom.