For over half a billion years, Earth’s magnetic field has risen and fallen in sync with oxygen levels in the atmosphere, and ...

A groundbreaking study suggests that the famous Cambrian explosion—the dramatic burst of diverse animal life—might have actually started millions of years earlier than we thought. By analyzing ancient ...

Remove the top male spotty fish and, within minutes, the next-in-line female morphs into the tank s new tyrant charging and nipping rivals while her body quietly begins a weeks-long transition to male ...