As far as evolution is concerned, genital size doesn't matter — but shape does. Genitalia are important in the evolution of new species, since compatible parts are necessary for two individuals to ...

Believed critical for determining which individuals can -- or cannot -- successfully reproduce with each other, genitalia not only figure prominently in the origin of new species, but are also ...

Surprising pattern: The genetic programmes responsible for the development of sex-specific organ characteristics in mammals are turned on almost exclusively late in the development of the organs, in ...

Biological sex is usually described in simple binary terms: male or female. This works well for germ cells (sperm versus eggs), but for other body organs it is of little help. Subscribe to our ...

HUSAVIK, Iceland (Reuters) - Sigurdur Hjartarson is missing a human penis. But he's not worried: four men have promised to donate theirs to him when they die. Sign up here. Hjartarson is founder and ...

Get countless emails, texts messages and phone calls from readers who want to learn more about the size of the male sex organ. Because of this and the many questions that demand urgent answers, I ...

The ostentatious, sometimes bizarre qualities that improve a creature's chances of finding a mate may also drive the reproductive separation of populations and the evolution of new species, say two ...

The “battle of the sexes” usually refers to a conflict of gender, but a different, biological sex battle has been ongoing for millions of years. “Sexual conflict,” as scientists call it, describes the ...

As far as evolution is concerned, genital size doesn't matter — but shape does. Genitalia are important in the evolution of new species, since compatible parts are necessary for two individuals to ...