This is Scientific American's 60-Second Science. I'm Karen Hopkin. This will just take a minute.
Modern human babies are essentially learning machines. After birth, their brains grow in leaps and bounds, allowing infants to lay the groundwork for future social and cognitive achievement. But it wasn't that way for Neanderthals. At least in terms of the shape of their brains, Neanderthal newborns pretty much coasted into adulthood.
Scientists have shown that Neanderthal brains are about the same size as ours. Yet our Paleolithic brethren are not known for having been great scholars. To probe this cognitive conundrum, researchers took CT scans of 11 Neanderthal brains, including one newborn. And they compared these images to those of modern humans.
They found that baby braincases are similar in size and shape, regardless of their parentage. All are elongated, most likely to smooth passage through the birth canal. But modern human baby brains grow more globular in the first year of life, changes that reflect a massive wave of neural development. That phase change is absent in Neanderthals, whose brains retain that extended newborn shape throughout their lives. The results appear in the journal Current Biology.
It's not clear whether our well-rounded brains made us the pointy-headed intellectuals we are today. But they do make us look smart in a cap and gown.
Thanks for the minute. For Scientific American's 60-Second Science, I'm Karen Hopkin. |