Kristen C. French

A new technique reveals human evolution was rife with interbreeding

The fungal puppet master has been living a secret life

The features of fish that have passed through the Suez Canal provide clues

For women of every race, age, and size

Defense Secretary Pete Hegseth is requiring service members to screen for low testosterone levels. Ironically, the military lifestyle itself is more likely to lower T levels.

It marked the city's first smog incident. Here’s what it looked like—back then and over the years that followed.