Imagine a future where a diagnosis of untreatable male infertility is no longer the end of the road—because science has found ...

The use of two sex categories to talk about a species is standard in biology. In many animal species, including people, however, there are individuals who are neither male nor female or who are ...

After a spell, a senior male lifts his head and turns from the ... a research associate at Stanford University's Center for Conservation Biology. "These calls show us that there's much more ...

an evolutionary biologist at Kansas State University in Manhattan. Yet a definition of biological sex put forth by U.S. President Donald Trump designates people as either male or female based ...

A January executive order by President Donald Trump designates people as female if they make the “large” reproductive cell (the egg) and male if they make the ...