Health Editor’s Note: I thought primates also had chins, but as described here they do not. I wonder why we have that extra piece of bone on our face? Any ideas out there?……Carol
A Chin-Stroking Mystery: Why Are Humans the Only Animals With Chins?
by Danny Lewis Smithsonian.com
Many scientists have stroked their chins in puzzlement over…well, the human chin. The bony nub that juts out from the bottom of the lower jaw is unique in the animal kingdom, and although researchers have proposed several theories over the years as to why, the chin remains a mystery.
The chin isn’t just the lower part of your face: It’s a specific term for that little piece of bone extending from the jaw. While it may seem odd, humans are in fact the only animals that have one. Even chimpanzees and gorillas, our closest genetic cousins, lack chins. Instead of poking forward, their lower jaws slope down and back from their front teeth. Even other ancient hominids, like the Neanderthals, didn’t have chins —their faces simply ended in a flat plane, Ed Yong writes for The Atlantic.
“If you’re looking across all of the hominids, which is the family tree after the split with chimpanzees, there [are] not really that many traits that we can point to that we can say are exclusively human,” Duke University’s James Pampush tells Robert Siegel for NPR. “[T]hose animals all walked on two legs. The one thing that really sticks out is the chin.”