BIOLOGY

High blood pressure guidelines have changed recently, which means Americans are more likely to receive a hypertension diagnosis than ever. Here are some essential facts about high blood pressure symptoms and causes.

Astronaut Scott Kelly used cotton swabs to take samples of his fecal matter. He then sealed it in tubes and sent it back to Earth via rocket.

Archaeologists and geneticists are looking at how human hair, and its countless hair types, evolved over millennia. Their research could shed light on the habits of our ancestors.

Saliva is more important than you think: You need spit to taste, chew, swallow, and digest everything you eat. Your spit even fights tooth decay and cavities.

Ancient Romans put it in everything—even their wine.

They're not really falling from the sky—but the reality is perhaps even more disturbing.

Those 52 foot bones do a lot of heavy lifting.

This gives "UPS" a whole new meaning.

See how many you know.

The ins and outs.

Organisms called 'Dickinsonia' defied classification for decades.

It involves something called a "love dart," and it's less romantic than it sounds.