sex

Molecular detective work is zeroing in on the origins of sexual reproduction. The protein tools for cell mergers seem to have long predated sex — so what were they doing?

Showy male competitions over mating privileges have grabbed scientists’ attention more often, but new work hints that sexual selection is also widespread among females.

Catherine Dulac is overturning preconceptions about “male” and “female” instincts and opening new avenues to treating postpartum depression.

Readers simulated the genetics of dog breeding to solve a puzzle about mixed breed percentages and sexual reproduction.

Solve a puzzle about mixed dog breeds, sexual reproduction and the COVID-19 pandemic.

Why did sex evolve? Theories usually focus on the diversity of future generations, but some researchers find compelling explanations in the immediate benefits to individuals.

Among these cave insects, the females evolved to have penises — twice. The reasons challenge common assumptions about sex.

Some species have the equivalent of many more than two sexes, but most do not. A new model suggests the reason depends on how often they mate.

The oldest law of genetics says that gametes combine randomly, but experiments hint that sometimes eggs select sperm actively for their genetic assets.