Armpit Hair

So I am studying for my last final, Physical Anthropology, and it occurs to me that chimpanzees have a whole lot of hair everywhere but their armpits. My book says that early hominids probably had a full hair coat similar to today's African apes, but that Homo erectus was the first hominid to have bare skin. Something about a diurnal hunter-gather lifestyle on the African savannah requiring a very effective cooling mechanism: sweating. So I'm wondering how exactly the current pattern of hair ended up being the advantageous one selected to be passed on. I can see the importance of hair on your head, to protect it from the sun, and for hair certain other places, especially when you're walking around naked, but armpits? What is the deal with that? It would seem to me that it merely holds sweat and other nasties in a hot place, a veritable breeding ground for bacteria and disease. Granted, I shave because I'm a girl, so I really don't actually know what it is like to have a lot of armpit hair; but I'm guessing that it is unpleasant and gross.
Another thing I wonder about armpit hair is if black people have really curly armpit hair, similar to the hair on their heads? I just don't know.

In other news, I think I aced the hell out of my philosophy final, securing me an A in the class. I was the first person done; it took me about 10 minutes, so I spent an equal amount of time just sitting in class waiting for the test to start as I did actually taking the test. Um...Tyler post here.

EDIT: I did in fact ace the hell out of that final; I got a 100%!! Holy shit! I didn't think I had done that good.