Sperm may lose their ability to navigate in microgravity, raising new questions about whether human reproduction is possible in space.

The central premise of the blockbuster film “Project Hail Mary” is a long-shot mission with a familiar goal: Save humanity ...

Knowing up and down seems key for sperm to reach an egg.

Being able to reproduce both sexually and asexually gives the dragons an evolutionary edge, Garcia says. If no mate is handy, a female can bear sons parthenogenetically—and when they’re older, they ...