Homosapian men, bend a knee. Harvard researcher Julia Klaczko just published a paper in the Journal of Zoology which discovered that Caribbean lizard hemipenises—which are freaky as all get out and sneakily stored inside their tail-vents—evolve six times faster than their other body parts.
Klaczko poses a few different reasons why these creatures' penises are a bona fide blur of evolution. Some believe that female members of some species will actively seek out male partners whose genitals fit better with her own. And because we're all on this earth to get. it. on. and make babies! it's argued that this selection process—your penis is too fat and bumpy!—causes the male species to develop a particular kind of genital that the women are pining for. Sounds like a strange feminist allegory if you ask me.
Anyway.
Klaczko also poses an "arms race" speculation:
"But there’s also evidence of a kind of genital evolutionary arms race in some species, like the Muscovy duck. Researchers found the ducks’ genitals were quickly evolving to give each sex the upper hand, respectively. The male ducks were evolving more flexible penises in order to force mating on unwilling females. The female ducks responded by evolving more intricate, sensitive vaginas that gave them control over which partner actually managed to fertilize their eggs." — Kaleigh Rogers, Vice.com
Dang. What a wild world. This battle royale of genital evolution is a front-runner in a possible explanation of why these Anolis lizard penises are changing so rapidly, but sadly, the studies on female genitalia across the board are still sorely lacking—it seems science has got vaginas on their to-do list.
