Sexuality and gender are often at the forefront of cultural and political debate today. In his new book, The Sexual Evolution: How 500 Million Years of Sex, Gender, and Mating Shape Modern ...

Marine biologists have documented the first-ever “in the wild” observation of endangered leopard sharks copulating, and were surprised to catch not just two sharks in action, but three. The intimate ...

In the animal kingdom, penises can be spiked, split, corkscrewed—even detachable. They're one of the most diverse structures in biology. The human penis is so uniform, it's an anatomical outlier.

Last year, the New York Times (Mooallem, 03.29.10), published an article entitled "Can animals be gay?" which discussed biologists' recent and past discoveries of same-sex animal behavior, how ...

Michelle Spear does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...