Why Do Mammals Have Penises?

Penises or penis-like structures vary widely across the Animal Kingdom, but their purpose is entirely the same—to take sperm from the male’s body and deposit into the female’s body. “Theoretically, you could do that just with a simple tube, but yet when we look in nature we actually see that penises can be incredibly varied,” says the evolutionary biologist Dr. Patricia Brennan in this new film about the evolution of male genitalia. The documentary, by Sofian Khan, traces the penis from its evolution as a biological structure millions of years ago in prehistoric fish, to today. 

The documentary in its entirety can be purchased on iTunes, and more information about the film and its creators can be found on its Facebook page.