A duplicated gene evolved into a switch that determines sex in frogs, revealing how evolution can safely reshape critical ...

It’s not just about chromosomes. Or reproductive cells. Or any other binary metric. Many genetic, environmental and developmental variations can produce what are thought of as masculine and feminine ...

Biological sex is all over the news lately. Between the presidential executive order affecting passport policy, moving transgender inmates between prisons and regulating women's sports, appeals to ...

The Texas Senate has sent legislation to Gov. Greg Abbott (R) that would strictly define genders across state law based on male and female reproductive organs — potentially creating new hurdles for ...

The cellular biology of reproduction is often depicted as an epic journey, in which millions of intrepid sperm fight to be the first to claim the ultimate prize: the chance to fertilize the egg, which ...

Believe it or not, but ducks have a reputation for the unexpected: bizarre and intricate mating anatomy. According to ...