Human body hair and evolution

Why do modern humans have so much less body hair than other primates? A new theory proposed by two British scientists "challenges the widespread view that humans lost most of their hair to promote body cooling when early hominids moved to open savannah regions," arguing instead that the change was due to parasites and sex. We'll skip past the stuff about parasites and jump right to the sex.

The scientists further propose that relative hairlessness would have become a desirable trait. Sexual selection, they believe, helped us to evolve this feature, with some body hair remaining to enhance pheromone signals, and for other purposes mostly related to mating.

A skeptical colleague points out a common sense flaw in this reasoning (not that common sense is always right in science).

Dunbar also doubts that hairlessness became desirable for mating. "You tend to like what you have to like," he said. "I'm sure that baboons find hairless baboons quite unattractive!"

Well, yeah. Didn't these scientists ever see the Twilight Zone episode with the beautiful woman shunned by the pigface doctors and nurses? It's hard to imagine early hominids thinking, "she'd be much hotter if she shaved her legs" or "cute, but his beard is so Australopithecus."

Posted on Thu, Jun 12, 2003 at 8:00 AM