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.

Scientists warn that radiation and microgravity pose a major threat to human reproduction in space. Understanding these ...

As private companies race to build orbital habitats and government agencies sketch out Mars timelines, a fundamental ...

Scientists have created human eggs containing genes from adult skin cells, a step that someday could help women who are infertile or gay couples have babies with their own genes but would also raise ...

Most animals, including humans, carry an internal lunar clock, tuned to the 29.5-day rhythm of the Moon. It guides sleep, reproduction and migration of many species. But in the age of artificial light ...

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 ...