DF:
The soft hair is called “lanugo”. I’ve read about it in lots of books on human evolution, but don’t have an actual cite for you. It could be something completely differenct. Not sure if, for example, apes’ body hair starts off as “simian lanugo”. If not, then it might be a totally different thing in humans. I’ll do a little google searching later on today and see if I can come up with something.
Do other primates sweat?
If not, that might be a starting point for an answer to the OP.
The only other sweaty animal of which I am aware is the horse, which has very short hair as a rule. I’m guessing this makes it easier for the sweat to evaporate, and makes perspiration a more effective cooling adaptation.
So those who believe in evolution must believe that females have evolved higher than males?
It seems a significant percentage of the gay male community has wilfully de-evolved pubic hair. :rolleyes:
For info on the Aquatic Ape Hypothesis, one need go no farther than our very own site. bibliophage wrote a marvellous Staff Report on it.
From A Moment of Science.
My doctor told me these hairs may be responsible for late pregnancy nausea.
The question is based on a premise that is not true. That premise being that we evolved from apes.
We don’t know that our ancestors, and those of apes were as hairless as we are or as hairy as a gorilla.
The common ancestor could have easily been relatively hairless, and the subsequent divisions that became apes developed hair, whereas our division did not.
Sigene:
We do know that hairiness is the norm for mammals. Wouldn’t it be strange if our ape or pre-ape ancestors lost their hair, then all the remaining apes (except us) seperately evolved to a hairy state again? While your scenario is certainly possible, it’s extremely improbable.
According to this site (note that heterochrony is a more inclusive term which includes both neoteny and progenesis, a process in which the retention of juvenile features is achieved by cutting short development - rather than prolonging it - by reaching sexual maturity progressively earlier),
Of note is the fact that a) the lanugo is also present in other apes, and b) even the development of the lanugo is slowed with respect to those apes.
Oh, and thanks John Mace and Biggirl for the info about lanugo - I’ve learned something! 
DF: Thanks for the site. I’ll have to take some time tomorrow to read it more thoroughly. On first take, this:
“the lanugo is retarded in man, for he has not completely shed it by the time of birth.”
sounds more like apes are neotenous wrt to lanugo and humans aren’t. I’m sure that can’t be right-- it must be getting late.
as soon as I hit the submit button, it made sense. Of course, retention of a fetal condion after birth is neoteny. It IS getting late…
The answer was on television tonight: The Life of Mammals with David Attenborough
It showed a bushman running down an antelope. The Bushman could sweat and replenish his sweat with carried water. The antelope could do neither. After eight hours, the antelope evenutally collapsed out of exhaustion and heat stroke. Throwing the spear was almost unnecessary.
We lost our hair so we could sweat. We could afford to sweat becuse we could carry water. We could carry water because we walked upright and had our hands free; we could carry water because because we were intelligent. The less hairy and sweatier and more intelligent had more food for their families.
Of course humans don’t need to carry water in order to be able to run. Even without drinking a moderately fit human will happily run for an hour without suffering more than minor dehydration.
Most mammals don’t sweat at all, and we have a different type of sweat gland to those few that do. Human glands produce sweat over a prolonged period. Other mammals tend to sweat in short bursts and then the sweat glands are depleted. Once you chase such an animal beyond the limit of ots sweat glands it begins tto overheat.
I’m surprised it took 8 hours to run down a gazelle. That’s a long time for an non-human animal to run for.