The discovery of a golden scaleless fish in China is helping scientists understand how animals evolved to live in caves.

With high carbon dioxide, low oxygen and no photosynthesis, here’s how an entire ecosystem persists in Movile Cave, one of the most extreme environments on Earth.

Deep under the Chihuahuan Desert is a natural wonder, a cave filled with beautiful giant crystals, but which also happens to be a potential death trap.

The venomous centipede crawled into the Movile Cave millions of years ago and adapted to live in the pitch black, surrounded ...