PBS Eons has a new episode. This one is about chins and how/why it fits into human evolution.

Check out the first episode of Human: https://to.pbs.org/HumanNOVA

You share a trait with every single human who’s ever lived – but no other animal on Earth has it.

It’s not your big brain, or your opposable thumbs… it’s actually this little shelf on your face that we call a chin.

And here’s the thing: we’re not totally sure why it exists.