Where did it start? How did it grow complex? Why did it get big? Three moments in Earth’s early history when evolution suddenly, inexplicably turned up the dial.

Cephalopods are masters of camouflage. Scientists want to decipher how the process works in the brain.

The justices heard arguments over whether the U.S. Air Force can keep destroying munitions on a Guam beach under a program it began in 1982.

In the battle for an Alaska Senate seat and the governor’s mansion, the oil-dependent state’s declining fisheries loom large, but no one wants to look at the biggest culprit, climate change.