LONDON: Scientists have finally found the reason behind the demise of the Neanderthals.An Oxford University study of Neanderthal skulls says that their large eyes were to blame for their extinction as their brains were adapted to allow them to see better and maintain larger bodies at the expense of high-level processing and intelligence. However, this ability enabled Homo sapiens to be more intellectually advanced and social, helping us to survive the Ice Age in Europe.Although Neanderthals’ brains were similar in size to their modern human counterparts, fresh analysis of fossil data suggests that their brain structure was rather different. Results imply that larger areas of the Neanderthal brain, compared to the modern human brain, was devoted for vision and movement and this left less room for the higher level thinking required to form large social groups.The analysis was conducted by Eiluned Pearce and professor Robin Dunbar and is published in the online version of the journal, Proceedings of the Royal Society Looking at data from 27,000–75,000-year-old fossils, mostly from Europe and the Near East, they compared the skulls of 32 anatomically modern humans and 13 Neanderthals to examine brain size and organization.In a subset of these fossils, the researchers found that Neanderthals had significantly larger eye sockets than modern humans. They then calculated the standard size of fossil brains for body mass and visual processing requirements. Once the differences in body and visual system size were taken into account, they were able to compare how much of the brain was left over for other cognitive functions.Previous research by the Oxford scientists showed that modern humans living at higher latitudes evolved bigger vision areas in the brain to cope with the low light levels. “Since Neanderthals evolved at higher latitudes and also have bigger bodies than modern humans, more of the Neanderthal brain would have been dedicated to vision and body control, leaving less brain to deal with other functions like social networking,” said Pearce.“Smaller social groups might have made Neanderthals less able to cope with the difficulties of their harsh Eurasian environments because they would have had fewer friends to help them out in times of need. Overall, differences in brain organization and social cognition may go a long way towards explaining why Neanderthals went extinct whereas modern humans survived.”