The Mystery of the Human Chin

Pointy, angular, round, sharp, defined, next to non-existent…

Chins come in all shapes and sizes. And amazingly, humans are the only ‘animals’ that have this unique lower jaw that juts out from the face. Even chimpanzees and gorillas, our closest relatives, don’t have properly formed chins. Yes, they do have an area below their jaws, but instead of jutting out, it slopes backwards.

So why are humans the only beings on the planet that have chins? The question has puzzled evolutionary biologists for centuries, with James Pampush, a postdoctoral associate in evolutionary anthropology at Duke University, recently shedding light on the matter.

He explored the mystery of the human chin in the journal Evolutionary Anthropology, explaining in a post publication interview that “The chin is one of these rare phenomena in evolutionary biology that really exposes the deep philosophical differences between researchers.”

The enduring mystery of chins…

Back in Victorian times, evolutionary biologists believed that the chin developed as an effective asset for deflecting punches. A form of self-defence if you will. Other theories propose that the chin helps the jaw manage the physical stress that goes hand in hand with speech, or that the chin is a ‘sexual selection’ tool that indicates evolutionary advantage.  

While there is no shortage of theories, Pampush maintains that the chin is simply a ‘red herring’ that doesn’t serve any direct purpose. He conceives that it’s a possible by-product of the human face reducing in size as food production and refinement was introduced. While the theory is more legitimate than some, it doesn’t categorically prove that the chin doesn’t offer humans some form of evolutionary advantage.

Did the humble chin put us at the top of the food chain?

Even Pampush is still open to the idea that the chin may have been the difference between human domination, and the rise of a different species. “If you're looking across all of the hominids, which is the family tree after the split with chimpanzees, there's not really that many traits that we can point to that we can say are exclusively human... The one thing that really sticks out is the chin. Perhaps it will tell us really what gave us that last little step into becoming anatomically modern that left those other human-like creatures behind,” muses Pampush.

Modern science offers fascinating insight into how the human body has evolved. ‘Advances in Multi-mode Mass Spectrometry for Tissue Imaging Studies’ surveys the field of liquid chromatography mass spectrometry (LC-MS), and the important role it plays in characterising complex biological mixtures at the protein and metabolite level.

Image via Flickr Creative Commons. Photo credits: Neil Moralee