Every year, more than 400,000 crabs are bled for the miraculous medical substance that flows through their bodies—now pharmaceutical companies are finally committing to an alternative that doesn't harm animals.

A unique experiment shows how multicellular organisms might have evolved from single-celled ancestors.

The most promising future of lab-grown meat may not look like meat at all.

For years, people have understood them to be at imminent risk of extinction, despite evidence to the contrary. Why?

Scenes from our national parks

Bristle worms reproduce at the same hour every month. How do they do it?

In its ideal form, a contraceptive vaccine could prevent pregnancy without the messy side effects of some hormonal birth control.

Prion diseases are poorly understood, and this one is devastating.

Rising temperatures are releasing mercury into the Arctic.