A recent Trump executive order defines sex based on gamete size. But the order oversimplifies genetics, hormones and reproductive biology.

The U.S. Department of Health and Human Services issued guidance updating its official definitions of terms such as sex, ...

Marmalade hoverflies leave northern Europe each autumn to escape the cold winter. A study, by the University of Exeter, compared the number of males and females migrating at a northern point (Denmark) ...

A new study observed Amazon river dolphins for 218.9 hours and saw males spurt urine into the air 36 times—proof that the ...

Study author Justin Scioli told McClatchy News that the shrimps are a type of hermaphrodite that all start out as males but later develop both male and female sexual functions. The new species takes ...

In this game, players are given the choice of whether they want to take a female or male lead protagonist as their character. The gameplay and narrative didn’t change at all as it was just a ...

JERUSALEM, Jan 25 (Reuters) - The Palestinian militant group Hamas on Saturday released four Israeli female soldiers, who were exchanged for 200 Palestinian prisoners incarcerated in Israeli jails.

Roula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter. Four female Israeli soldiers held hostage by Hamas have returned to Israel while 200 Palestinian prisoners ...

The order calls for the federal government to define sex as only male or female and for that to be reflected on official documents such as passports and policies such as federal prison assignments. As ...

Trump's executive order declares sex as "an individual's immutable biological classification as either male or female" and states that "gender identity" cannot be included in the definition of ...