Scientists surmise the shape of human brains is more important than its size when determining why Neanderthals eventually died out.
When our early human ancestors slowly migrated away from Africa 40,000 years ago, the Neanderthals that had flourished in Europe for over 200,000 years began to die off, and a new study suggests that it may be the shape of human brains, rather than their size, that is one of the key reasons that humans eventually triumphed over the Neanderthal species.
For a long time, anthropologists have wondered what it was that gave humans an edge over Neanderthals, and now a research team consisting of neuroscientists, physical anthropologists, and mechanical engineers have worked together to try and recreate Neanderthal brains through the process of digital reconstruction, as Phys.org report.
After looking closely at the brains of humans and comparing them with those of Neanderthals, researchers have concluded that it wasn’t just the mere size that allowed humans to triumph in the end, but that the real key may have been in a different way that humans process information.
In order to build the digital reconstruction of the Neanderthal brains, scientists took four Neanderthal skulls and very carefully used the insides of these to take accurate measurements of their shapes.
Next, researchers obtained MRI scans from 1,000 humans so they could come up with a general average of the modern shape and size of the human brain.
The shape, not size, of our ancestors’ brains may have helped them outlast #[email protected]://t.co/LglxUFRytw
— Phys.org (@physorg_com) April 29, 2018
Once researchers had the digital reconstructions of the Neanderthal and human brains, they used a special computer program so that the image of the human brain could be warped, thereby neatly fitting the human brain scan inside the skull of the Neanderthal.
Scientists were able to immediately recognize that while the human and Neanderthal brains were not dissimilar in size, the shape of the brains was actually quite different. Most notably, the cerebellum of the Neanderthal brain was much smaller than that of the human brain.
With the cerebellum responsible for cognitive flexibility, speech and memory, the fact that this region was so much larger in human brains would clearly have put humans ahead of Neanderthals in many ways.
Researchers believe that because of their smaller cerebellums, Neanderthals probably would have suffered greatly when it came to adapting to their environment after humans came onto the scene.
However, scientists did notice that one particular region of the Neanderthal brain, the occipital lobe, was in fact much bigger than in human brains. With this part of the brain dealing with visual processing, in this way Neanderthals would have had a clear advantage over humans.
On the other hand, because of the size of the occipital lobe, it is very possible that their cerebellum would simply not have had ample room to grow to the size that it did in humans.
As Keio University’s Naomichi Ogihara explained, it is important to realize that the technology that was used in this study is still quite new, and further studies will need to be conducted to further examine the relationship between the shape and size of human and Neanderthal brains.
“We would like to further elaborate our methodology by exchanging thoughts and ideas with researchers in the related fields working on human brain evolution.”
The new study speculating on the shape of human brains putting us ahead of Neanderthals has been published in Scientific Reports.
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