Eeew!

Pubic Lice Acquired From Gorillas

Pthirus pubis, popularly known as crabs, evolved from the structurally similar gorilla louse, Pthirus gorillae. Interestingly however, while genetic analysis carried out by David Reed at the University of Florida indicates that this split occurred around 3.3 million years ago, humans are believed to have diverged from gorillas much earlier - at least 7 million years ago - suggesting that early humans somehow caught pubic lice from their gorilla cousins. Happily, this may not be as sordid as it sounds.

According to Weiss, "Before one conjures up a King Kong scenario, it should be noted that predators can pick up parasites from their prey. The close contact involved in human ancestors butchering gorillas could have enabled Pthirus to jump hosts, rather as bushmeat slaughter practices allowed HIV to invade humans from chimpanzees in modern times."

 Oh, that makes it OK, then...