Evolution of the Penis and Our Missing "Penile Spines"


In the natural world there are all kinds of penises. Some animals have barbs and spikes on their penis. Some animals have a baculum or a penis bone to support their erections, and some have a hemipenis, which has two projections (double your fun). Some animals like the banana slug even have a penis that grows out of the top of their head.

But humans have undergone their own type of penis evolution...losing those "penis spines" is apparently part of what makes us human. Researchers from Pennsylvania State University have recently published a report in Nature indicating that humans are missing a sequence of DNA that leads to the development of "penile spines." Our Neanderthal ancestors are noted to have an absence of the DNA sequence needed to produce a penis spine, "suggesting that the human penis lost its spine somewhere between 7 million and 800,000 years ago." A penis without spines leads to sex that lasts longer and is thought to have a relationship to increased monogamy.

To learn more: http://www.bloomberg.com/news/2011-03-09/human-penises-evolved-to-promote-lon...