Humans Lost “Penis Spines” During Evolution

Friday, 11 March 2011 | by Pat's Picks

Thank you, evolution. The LA Times says scientists have been comparing the human genome to that of our closest relatives, chimps, to see what has been edited out of our DNA over the millennia. And there are quite a few deletions to be happy about, in particular that we have bigger brains, no whiskers and have lost our “penis spines.”

In a new report published in the journal “Nature,” scientists say we have lost several chunks of our DNA that chimps still possess, including “a gene for making an androgen receptor.” In layman’s terms: we lost the ability to produce mouse-like whiskers and penile spines. Shucks.

The BBC says penile spines are “barb-like structures” found in many mammals. Their actual function is under debate. Some experts believe they evolved to “remove the copulatory plugs left by other males.” Scientists believe they were erased from our DNA when human courtship rituals evolved: “The loss of spines would result in less sensitivity and longer copulation, and may be associated with stronger pair-bonding in humans and greater paternal care for human offspring.”

Here’s the Nature article entitled, “How the Penis Lost its Spikes.”