Re: Why did long hair evolve in humans?

Mark:

I think several other contributors have already hinted at the evolutionary 
purpose of head and facial hair, so I will just summarize a few thoughts.

First, the hair on the top of our heads is likely there to provide 
protection from cancer-causing ultraviolet rays and to help moderate blood 
temperature in extremely cold or hot weather.  Although there are many men 
who lose their hair in their 40s, 50s, etc., remember that several thousand 
years ago, a 50 year-old bald man would have been considered very, very 
old. With regard to hair cuts, we would first have to assume that keeping 
hair short would be a primary consideration, although I doubt there were 
many Cher Bono-types 35,000 years ago.  If we are talking about a 
tool-using people, hair could be cut with a sharp stone blade, as you 
suggest, but just banging the hair between two rocks would have been enough 
to sever it; pre-tool people could also have chewed their hair and beards 
off. I suppose it's possible that pre-stone tool people could even have 
tied long hair back with a short length of vine!

Aside from biological functions, I think hair has probably always had some 
"cultural" display function-- think about the evolutionary advantage that 
an early Homo Sapiens Elvis would have had!

Dan Pratt