EVOLUTION

Why Do We Have Eyebrows?

Eyebrows are the Swiss Army knife of the human face.

Gasping when you're surprised is a quirk of evolution.

Why Do We Gasp When We're Surprised or Alarmed?

Gasping is tied to an innate survival mechanism, hardwired into humans through evolution: the fight-or-flight response.

10 Facts About Wisdom Teeth

Why do we even have them? Let's get to the root of the issue.

Pucker your mouth when you eat something sour? You're not the only one.

Why Do We Make Weird Faces When We Taste Something Sour?

If you can't resist puckering your mouth when you lick a lemon or snack on Sour Patch Kids, you can thank evolution.

Meet the Sea Slug With the Disposable Penis

Fans of '90s alternative music may recall King Missile's big single, "Detachable Penis." While the song may have been silly, it turns out than in the animal world, the idea isn't all that bizarre—at least not to the sea slug Chromodoris reticulata.

Chimpanzees hang out in Gombe National Park.

9 Amazing Facts About Chimpanzees

Chimpanzees share about 98 percent of their genes with humans, but you wouldn't want to invite this side of the family over for dinner.

11 Fascinating Facts About Chipmunks

What do chipmunks eat? Baby birds, occasionally. Do chipmunks hibernate? Yes, but not like bears do.