Evolution question: Why pubic, armpit, facial, & scalp hair?

[Dinosaur]

Homo Sapiens evolved from primates which had hair (fur) over most (all?) of their body.

Why does the above hair still persist?

It there an evolutionary advantage? Is it merely a matter of no evolutionary pressure to become entirely hairless.

I suspect there is an advantage to facial & scalp hair. What about armpit & pubic hair?

 

[cornel]

We have a very strong social pressure to cut off hair(although not strong enough to make us cut off all of our hair)
And yeah, cutting, who needs to change his genes when he/she has scissors

I suspect there is an advantage to facial & scalp hair. What about armpit & pubic hair?

facial and scalp is nice and warm, though who needs that when we have clothes we can put on when it is cold ?
Armpit hair, well, i suppose it takes in some of the sweat, obviously only necessary if one sweats a lot.

 

[Read-Only]

Homo Sapiens evolved from primates which had hair (fur) over most (all?) of their body.

Why does the above hair still persist?

It there an evolutionary advantage? Is it merely a matter of no evolutionary pressure to become entirely hairless.

I suspect there is an advantage to facial & scalp hair. What about armpit & pubic hair?

There are some VERY good reasons.

Something over 50% of body heat is lost through the head in cold weather and both armpit and pubic hair aids in the dispersal of sex pheromones.

 

[Sorcerer]

We actually get hair around every orifice, don't we? Nose, ears and er, bum too. I suppose the first two help to expell unwanted material (this is getting gross now), but why do we have hairy bums? There doesn't seem to be any good reason.

 

[exchemist]

We actually get hair around every orifice, don't we? Nose, ears and er, bum too. I suppose the first two help to expell unwanted material (this is getting gross now), but why do we have hairy bums? There doesn't seem to be any good reason.

Bearing in mind that man seems to have evolved in a warm climate, I have always assumed the reason for hair in these places, aside from the scalp, is to avoid soreness from rubbing, especially when sweaty. Scalp hair would protect from the sun, as does the extra thick hair a camel grows along the centreline of its hump.

 

[Sorcerer]

Bearing in mind that man seems to have evolved in a warm climate, I have always assumed the reason for hair in these places, aside from the scalp, is to avoid soreness from rubbing, especially when sweaty. Scalp hair would protect from the sun, as does the extra thick hair a camel grows along the centreline of its hump.

That seems reasonable. Sweaty bums would solve the conundrum.

 

[exchemist]

That seems reasonable. Sweaty bums would solve the conundrum.

Yup. And the pad of pubic hair both sexes have is right where the most of the load is taken during sex.

 

[Sorcerer]

Yup. And the pad of pubic hair both sexes have is right where the most of the load is taken during sex.

You are an expert at sweaty hairy bits.

 

[exchemist]

You are an expert at sweaty hairy bits.

What may be interesting, if my hypothesis is correct, is that face to face sex has been going long enough in humans for hair distribution to have evolved to optimise it. But then I'm not sure if we are unique in this respect or if any other primates do this.

 

[Captain Kremmen]

Why don't Hippos and Mice have head and armpit hair?
Or maybe they do.

I've tried googling, but none of the images show their armpits.

 

[Sorcerer]

What may be interesting, if my hypothesis is correct, is that face to face sex has been going long enough in humans for hair distribution to have evolved to optimise it. But then I'm not sure if we are unique in this respect or if any other primates do this.

A quick google seems to say that chimps do face-to-face as well the other way round. (I would post the pics....)

 

[exchemist]

A quick google seems to say that chimps do face-to-face as well the other way round. (I would post the pics....)

Ah, so it may have been present in a common ancestor - plenty of time for hair distribution to optimise itself.

 

[origin]

Bearing in mind that man seems to have evolved in a warm climate, I have always assumed the reason for hair in these places, aside from the scalp, is to avoid soreness from rubbing, especially when sweaty. Scalp hair would protect from the sun, as does the extra thick hair a camel grows along the centreline of its hump.

I agree with this. Hair is a good dry lubricant, it prevents chaffing. Nose hair is a good filter for dust, as anyone who does work in a dusty environment can attest to. Hair on the head makes sense because of the high heat loss from the head. or in a hot environment it is a ready made hat..

 

[exchemist]

Why don't Hippos and Mice have head and armpit hair?
Or maybe they do.

I've tried googling, but none of the images show their armpits.

Well, pachyderms hace far tougher skin and they don't sweat, so would not be expected to suffer from chafing, while mice are furry all over.

 

[Captain Kremmen]

Pachyderms don't sweat. You are a fund of information.

 

[Captain Kremmen]

Hippos do have hair.
Especially on their ears and below their noses.

I would still like to see their armpits.
Or should that be legpits.

 

[Sorcerer]

Hippos do have hair.
Especially on their ears and below their noses.

I would still like to see their armpits.
Or should that be legpits.

Find one, tap it on the shoulder, and ask to see it's pits. Politely. Guaranteed to work.

 

[exchemist]

Pachyderms don't sweat. You are a fund of information.

Well I had to look that up, in response to your challenge, so thanks, I've learnt something as well!