Humans don’t have a defined mating season like deer or wolves. Here’s how evolution blended biology, culture and social life into year-round intimacy.

Human biology evolved for a world of movement, nature, and short bursts of stress—not the constant pressure of modern life. Industrial environments overstimulate our stress systems and erode both ...

Elephants are pregnant for up to two years. Females of some fish species starve for weeks while holding dozens of eggs and hatchlings inside their mouths. And pregnant humans commonly endure months of ...