Dormant genes on the X chromosome may reawaken in old age, potentially giving the aging female brain a boost that the male brain doesn't receive. This phenomenon may help to explain why, on many ...

In evolutionary terms, fitness is defined as an organism's ability to survive and reproduce its genes into the next ...

Women have a higher proportion of key immune cells between puberty and menopause, which may be linked to the sex hormone ...

Preserving the integrity of competition in the female category is a fundamental principle of the sport of athletics,” the ...

World Athletics president Sebastian Coe says the track and field’s governing body has approved the introduction of cheek ...

"The primary sex hormones - estrogen in females and testosterone in males - are thought to play a role in these differences, as are the sex chromosomes (XX in people registered female at birth, and XY ...

World Athletics president Sebastian Coe announced Tuesday that female track and field athletes will undergo random genetic ...

Alongside hormones, the sex chromosomes — X and Y — are one of the starkest biological differences between males and females, and they could help provide biological explanations for why these ...

The planned changes include reinstating a version of chromosome testing that was discontinued in the 1990s, requiring athletes who compete in the female category to submit to a cheek swab or dry ...