Why humans have no fur: Bare skin --> Bigger brains (Scientific American)

[brandon]

^Good points, though the one about better ventilation is perhaps not so important if one is nude.

I've read that one possible evolutionary advantage of male facial hair (beyond sexual selection by females) is that it makes a man appear larger and therefore more intimidating to other males. That might help a bearded male avoid a fight in which he might be killed. Also, in a competition over sexual access to a female, the intimidating bearded man might scare off a male with less or no facial hair.