Penis Spines? No Thanks!
Here’s a fun fact for you to bring up next time you’re inebriated and want to raise a strange topic at a dinner party: men don’t have penis spines. That is to say, the penises of human males differ from our nearest genetic relatives, the chimpanzees, because there are no “tactile” spines or barbs on the end that induce female ovulation and clear out the sperm of other males. Chimps Read More …