Environment
Mass of spawning fish make a milky way on a coral reef
When photographer Tony Wu went to Palau to watch red snapper spawn he discovered why so few photos of the spectacle exist
Regulars
Environment
Why does semen make female fruit flies more aggressive?
Opinion
Health
Boost C-section babies by giving them vaginal bacteria
News
Environment
Howler monkeys have to choose between big balls and big bawls
News
Humans
Why did sex evolve? Blame an ancient hook-up
Opinion
Humans
Does parenthood really make us happier?
Features
Humans
Semen has controlling power over female genes and behaviour
News
Health
Mice evolve better, not bigger, balls in sperm race
News
Life
Infanticide drives female promiscuity and big balls
News
Health
Testicular time bomb: Older dads’ mutant sperm
Every man's sperm is fighting an evolutionary civil war – and over the years, it ups the risk of fathering a child with a genetic disorder
Features
Humans
Men with smaller testicles make better dads
News
Technology
The radioactive legacy of the search for plutopia
Books & Arts
Health
Can castration really prolong a man’s life?
News
Earth
Zoologger: First animal with ovaries on the outside
News