For Scientific American Science Quickly, I'm Kendra Pyr Lewis, in for Rachel Feldman.

Most of us, if we think about chins at all, do so rarely. But it turns out that chins are an evolutionary clue.

Among our primate kin, chins are a distinctly human trait, which raises a question.

Why do we have them?

Research that was published in January presents a strong potential answer.

To dig into the murky origins of the human chin, we spoke to one of the study's co-authors,

Lauren Schroeder, a paleoanthropologist at the University of Toronto, Mississippi.

Thank you for joining us today, Lauren.

Thank you so much for having me.

You recently wrote a paper looking into the evolution

of the human chin. This is maybe a very silly question, but like what is a chin? Yeah, so a chin is just a

bony sort of protuberance at the lower part of the jaw. In sort of scientific terms, we call this a mental

protuberance, but it's basically where the jaw comes together, you have this bone that is sort of sticking out a little bit.

We are the only species to have one.

Even our closest ancestor, Neanderthals, did not have a chin.

So it is unique to our species. You do raise an interesting, is it the three

little pigs where they say not by the hair, my chinny chin chin? Apparently, that is fake. Pigs don't have

chins. We've all been lied to his children. Before we get into sort of the theories that your paper posits, what are some of the

theories about like why humans have chins? Yeah. So because the chin is unique to humans, it has

been a question that has been sort of asked and tried to be answered over a very long time in

the literature.

And many different proposals exist.

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