"We understand what kind of struggle it is," Jack Grafe told "GMA." A set of twin brothers who transitioned from female to male are sharing their story in hopes of helping others who may be struggling ...

These days, talking about gender identity and transition is more open than ever. People who embrace their true selves share their stories, giving us a real look at what it’s like to go through this ...

The study measured “rank” within the bonobo communities by tallying how many times females won conflicts with males. Females usually came out on top. Photograph by Christian Ziegler By banding ...

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 ...