Extinct? Scientists may inadvertently have figured out why it is Neanderthals disappeared. It’s the eyes. And the rabbits.
A team at the University of Oxford has released a report on Neanderthals, speculating that their eyes were a big reason they died out about 28,000 years ago. The team studied the skulls of 13 Neanderthals and 32 homo sapiens (i.e. modern humans). They found the Neanderthal eye sockets were, on average, 6 mm bigger.
According to the BBC:
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.
Although 6 mm isn’t a lot, the bigger sockets took up space at the frontal lobe, an area linked to socializing skills, putting them at a slight disadvantage to homo sapiens. The Neanderthals also had bigger bodies, which needed more brain power instead of less. Since they weren’t as good at socializing, the Neanderthals would have lived in smaller communities, which put them at another disadvantage in terms of development. The Neanderthals could probably see better than the homo sapiens, but when conditions deteriorated — such as when the weather cooled at the start of an ice age — they were less skilled at dealing with it.
There is archaeological evidence, for example, that the Homo sapiens that coexisted with Neanderthals had needles that they used to make tailored clothing. This would have kept them much warmer than the wraps thought to have been worn by Neanderthals.
Another study, written up in the National Geographic, suggests the Neanderthals lesser hunting skills — or sheer stubbornness — also contributed to their demise. In this report, biologist John Fa notes that rabbits became a much more important food source as bigger prey like the woolly mammoth began to disappear. Neanderthals were known to be real pros at hunting mammoths, but evidence suggests they didn’t bother with rabbits, which instead became popular with homo sapiens.
Rabbits are smaller, faster and harder to catch than big lumbering mammoths, and required different skills and equipment. “The process could have been too demanding for Neanderthals, who likely had higher energy requirements than modern humans,” suggests the report. It also projects that, given the size of Neanderthals, and their inferior clothes, a measly rabbit or two wasn’t enough nourishment to justify the effort they’d have to put into it. Another advantage of the homo sapiens was their partiality to dogs, which helped with the hunt.
The oldest fossil evidence for dogs is only about 12,000 years old, but there is genetic evidence suggesting dogs may have split from wolves as far back as 30,000 years ago-around the time that humans were arriving in Europe.
So … big eyes, inferior clothing and a distaste for rabbit. A few more woolly mammoths and they might still be with us.