purpose of pubic hair ...

http://www.straightdope.com/columns/read/54/whats-the-purpose-of-pubic-hair

The purpose of pubic hair is to distinguish children from adults. Think about it from a Darwinistic point of view. The average caveman had a better chance of leaving surviving progeny if he/she mated with fertile partners. Children are infertile and lack pubic hair; adults are fertile and have it. Public hair is thus a marker for fertility, so that our distant ancestors could avoid infertile partners who were a waste of time. Those who passed their genes to us were probably too busy trying to survive to put too much energy, risk, and effort into nonreproductive sex.

–Steve

Facial hair would work just as well, and the face is less likely to be covered in cool weather.

Not to mention the other signs of fertility, like wide hips, that serve the additional purpose of being a better fetus holder. A large hip-to-waist ratio would have been (is) a very good indicator of fertility that wouldn’t carry the disadvantage of taking more energy and matter to make.

Nope, there’s gotta be somethin’ else. I suspect, as Cecil alludes to, it’s the scent concentrator. Back when people liked people that smelled like people, a nice hairy bush would trap those gorgeous womanly smells and hang on to them.

Canadjun, it doesn’t matter what would have worked, 'cause it wasn’t a plan or a design. It would have worked for people to turn purple at sexual maturity, too, but that doesn’t mean the mutation ever would have happened.

I always thought it was a lubricant like underarm hair, so as to, you know, prevent chafing when bumping uglies.

Just realized that I had a major brain fart in my last message. I was (probably obviously) only thinking about boys/men. Ignore my previous message. :smack:

If fertility-indication were the reason for pubic hair, I think women would be bearded too, or grow a beard at certain times of the month.

Have you ever been to Turkey?

The ladies must really love you in bed… I don’t think I’m physically capable of performing enough sex for it to endanger my survival. :slight_smile:

There’s a whole field of study in the evolutionary development of the body and what it signals.

Women, for example are softer and less muscular (except Turkey?) as well as less facial hair. This signals the proper balance of estrogen vs. testosterone that indicates the female has the correct balance of hormonse to be fertile.

Women also are “rounder” (“except in that dress dear, honest”) to indicate they have the overall layer of fat necessary to feed a baby for 9 months, even if the roots and berries crop fails.

These also make a woman appear younger and more child-like so that they signal “still a lot of child bearing years left”. It’s an attractor. It says “pick me for your trophy wife, you alpha male!”

One theory says that this is what blonde is too. Many children are much fairer haired when young, getting darker with age. Blonde appears to be a mutation where the darkening did not happen; it has the bonus of making the woman appear to be a youngster.

To balance the “young” there are signals that the woman is mature enough to be fertile. Wide hips indicate the pelvis can pass a baby’s skull, somewhat useful in the days before c-sections. The ratio of leg length to torso length is another. Women have longer legs. there’s an interesting essay on the “transformation” scenes in Sailor Moon, one major feature (which many adolescent males miss, concentrating on other things) is that the super-hero legs are significantly longer.

Breasts -duh! - are another maturity indicator, which have child-rearing advantages.

I suspect pubic hair is one of these indicators, as well as, like Cecil suggests, doing duty as a fluffy air-freshener in the days before pine-scented cardboard tree outlines. Like eyebrows and armpit hair, it also probably sops up sweat to prevent dripping that could annoy and cause chafing in sensitive areas.

BTW, there is an area of India where body hair is another one of these “maturity” indicators locally. Women from there have noticeable thin but long sideburns and arm hair (I’ve only seen a few, and I have no idea what their covered parts are like - if their arms are any indication, they probably go through a razor every day shaving their legs.)

I read some article once on maturity and visual indicators; it pointed out that typically men are reproductively capable before they display significant obvious outer signs like size and beards. This means they can get some breeding done before other males consider them rivals (we wish!) with all the head-butting male rivalry that ensues. Women, on the other had, tend to develop the signals before they are fertile, in order to already have a mate around and supplying protection and gazelle meat when reproduction starts happening.

Except I don’t think that is true. Teenage girls have longer leg to torso ratio, but they then grow up. Women tend to have shorter arms and legs per torso length.

That is one reason high heels are common for women. Besides the supposed shapeliness enhancement, it also makes the women look taller and legs look longer.

You apparently didn’t read Cecil very closely. He says hair functions as a scent concentrator, not a scent diluter.

Don’t know about you, but my armpit hair doesn’t do a particularly effective job of sopping up sweat, or preventing it from dripping.

um… the purpose of pubic hair is warmth…

Then why don’t babies have any? Or if babies are going to be with their parents anyway because they’re not mobile, what about 5 year olds? They tend to be fully capable of independent motion and getting far enough away from parents to need their own environmental protection systems, yet they don’t have pubic hair.

md2000, public hair is definitely one of many signs of fertility and maturity, but it has several problems in that regard. First and foremost, pubic hair grows before you become sexually mature, and it never falls out. This makes it a much less reliable indicator than things like menstruation, which is not only quite noticeable but the only “perfect” indicator of fertility.

But - more importantly - determining the fertility of a partner isn’t really all that important to human beings. Humans can mate virtually as often and with as many partners as they want to (or are permitted to). It’s not like we’re mayflies that get one shot at it and then die.

Babies have to grow and develop. Sure they don’t have pubic hair but they also don’t have teeth or knee caps or complete skulls. As with all other living beings they have to grow up.

Warmth?! For what? The pubic region is already one of the warmest regions in the body. *Too *warm, in fact, for the testicles, which had to evolve the external scrotum so they could keep cool enough to make functioning sperm. You’ve got not one, but two femoral arteries (one on each side) with a buttload of capillaries, muscle, fat and some of the thickest skin on the body all acting as thermal insulation and bringing hot blood to the area.

If there’s one thing the pubic region doesn’t need, it’s heat from pubic hair (which is too sparse to provide much of it anyhow). Toes and fingers are in far greater need of a nice thick insulating coat of fur than the pubic bone is.

Thanks for your kind reply.

All hair is for warmth plain and simple, what else could it possibly be.

Pheromone odor for mating attraction purposes? If that were so than all mammals would have pubes. But they don’t because they have substantial hair on other parts of their body (for warmth), and they don’t walk upright and ‘exposed’ as humans do.

Read about hypothermia… they say to curl up in a ball to minimize heat loss through your pelvic region and armpits. That’s why the hair. Also… you say there isn’t enough hair to keep warm… well sorry but there is… the perfect bush to keep warm air close to your body. Just like three layers of clothes is warmer than one thick layer.

Finally… take a close look. You have hair on your toes and fingers. Maybe at one time it was thick as that of a Mountain Gorilla, but, I’m just guessing here, humans evolved away from big ole hairy paws when we figured out how to live indoors.

Biologists might care to chime in here, but I would caution against the adaptationist bias. Sexual selection can be as important as, and sometimes more important than, adaptational selection (see, eg, the tail of the peacock).

Dawkins has said (quoted and amplified in Slate):
“Why did humans lose their body hair? Why did they start walking on their hind legs? Why did they develop big brains? I think that the answer to all three questions is sexual selection,” Dawkins said. Hairlessness advertises your health to potential mates, he explained. The less hair you have on your body, the less real estate you make available to lice and other ectoparasites. Of course, it was worth keeping the hair on our heads to protect against sunstroke, which can be very dangerous in Africa, where we evolved. As for the hair in our armpits and pubic regions, that was probably retained because it helps disseminate “pheromones,” airborne scent signals that still play a bigger role in our sex lives than most of us realize. (It occurred to me that becoming hairless also meant we didn’t have to spend all our leisure grooming one another to remove lice, like other primates, thereby freeing up time to create capitalism. But I kept this thought to myself.)

“Sexual selection works as a kind of amplifier, causing small and perhaps arbitrary trends to get exaggerated in a runaway fashion,” Dawkins continued. “It’s still a Darwinian process, but it’s one that allows for contingent extravagance.”

S J Gould also warned against the generation of adaptationist “Just So” stories to explain phenomena. He also pointed out the role of neoteny, which may have some explanatory power here: given that our hairlessness generally compared with our ancestors may be neoteny at work, the little islands of hair left may only be a vestigial remnant consequent upon the Retreat of Hair.

My problem with the Darwin Idea is this …
I (being Hairy myself) wonder if those of us who still have exessive body hair must therefore be “Closer” to our distant cousins “Less evolved” this would mean that there are LESS generations between me and them. If there are less generations that means that we must have LIVED longer (on average) each generation and our progenetors must have bred at a LATER age (on average) This seems to indicate we (the Hairy) are the BETTER Evolved. (Logically that is)

Signed:
"The Gnome

No. I’m sorry, but you obviously have no idea how or when evolution made its greatest impact on the morphology of humans. Hypothermia is such an infrequent occurrence in the rainforests and deserts of Africa where humans evolved that we can eliminate it as a major shaping force in 98% of our physical features - certainly the ones that Africans themselves display. At temperatures in which hypothermia is a danger, pubic hair makes no appreciable difference to the core body temperature of the individual, which is all that’s important. (Curling up may, but I doubt it’s because it protects your pubis, it’s more likely to be because it decreases your surface area.) And other apes have relatively bare paws- that trait evolved before humans did, much less indoor housing.

“What else could it be for?” Any of the other proposals - fertility identification, odor concentration, even the prevention of chafing during intercourse - are far more likely than insulation over a very small and not very cold part of the body which is itself not very susceptible to damage by cold.

I’m not an evolution expert, but no, that’s not how it works. How much hair you have is related to where your ancestors came from and that’s about it.