Considering the majority of the male population say in australia, if not the world shave their faces on a regular basis, how long would it take us if it happens for us to evolve to have no facial hair?
Are you suggesting that shaving would cause us to evolve that way? That would be a form of “evolution by acquired characteristics,” a theory that was abandoned about a hundred fifty years ago.
No not saying shaving would cause it, more so enquiring whether, because we get rid of the hair as it is, it seems to be serving little purpose, therefore would we be slowly able topush this out of gene pool.
Im not sure of the technicallities, im just having one of those hangover days where you get that dirty great stubble that you just couldnt be arsed shaving and hope that one day our ancestors wont need to go through the rather annoying process of shaving each morning.
More is it likely or not question
Barring a few recent articles I’ve read where that theory has been again rearing its ugly head, I agree with Tomba.
To understand why this theory doesn’t work you must first understand why those of us who are of Northern/Western European ancestry tend to have chest hair, facial hair, thicker arm and leg hair, and sometimes even the dreaded back hair.
Simply put, hair provides us with warmth. Not a huge amount, but it’s better than nothing.
Long ago when people began to move into the northern european parts of the world, many of the people probably did not have body hair.
If current thought is correct and humanity slowly migrated outwards from southern africa, then it in fact probably stands to reason that there were certainly a great number of people who had, through evolution, lost their body hair.
As humanity migrated north, the people with body hair survived better because they weren’t as effected by the cold. Now, we’re talking thousands upon thousands of years ago, when fire probably wasn’t widely available, shelter was iffy, clothing probably iffy as well. So body hair meant something.
And since people with body hair tended to survive more, culturally they probably became more “prized”, because mates with better survival attributes have always tended to be more prized.
So both through the process of women going to more “prized” mates and good ole fashioned natural selection, whatever lesser haired peoples there were in europe slowly were mated out of the population.
As more and more of the population had the genes for hairiness, it became more and more likely for two couples carrying that gene to mate. They had kids who had the gene, and this happened hundreds of millions of times until body hair and facial hair became de facto standard among europeans.
For many years in fact up until the late 19th century when razor technology improved, facial hair was a mark of manhood. You grew your facial hair out, the wealthy classes were the first to start shaving their faces regularly (although the practice goes back thousands of years.)
Body hair too was long a mark of manhood, and in some ways that perpetuated until the 70s/80s. Now body hair seems to be frowned on by many, and many people who naturally have body hair have been shaving it for years.
I think this is probably a product of the fashion/entertainment industry. To better show definition of muscles it is productive to shave off body hair. Since actors/models tend to be well built, they shave themselves to show that off. Eventually the general public saw enough of that they began to consider no body hair to be the norm, although genetically speaking it is the norm for large numbers of people.
This may slowly cause evolutionary changes, but not so much. While hairless people are more prized these days, many men are willing to shave their body hair so it really isn’t a big issue.
To speak personally I’ve always had thick chest hair and have always been able to grow an extremely thick beard.
Most women who I’ve been with for any length of time have liked it, because if they didn’t, then they’d be shown the door because I consider it a bit effete to shave off body hair unless your in some sort of athletic competition.
Well, I sort of see how that could work. If everyone shaves, the adaptive benefit of beards is negated, so there is no longer a selective pressure in favor of beards. That leaves two influences on the beardedness of the population: the slight disadvantage of the energy expenditure of hair growth, and random genetic drift. Energy cost is not going to matter much in the industrialized world, with its overflowing energy. But in the poorest nations, it might matter enough to reduce beardedness over time. As for genetic drift, it might just as easily increase beards as reduce them, so we could wind up seeing greater variation in beardedness.
But these processes would probably take thousands of generations to show any effect. In that time, they are likely to be overwhelmed by other factors. Beards could come back into fashion, for example. And remember that some societies don’t conform to our model—they encourage long beards—but there is still constant gene flow between them and the rest of the world.
And it’s possible that some of the selective benefit of facial hair would not be negated by shaving. Sexual selection might still operate, because men with thick beards look different from beardless men even when they are shaven!
Probably the most likely way for beards to die out would be if all of humanity were wiped out in a catastrophe except for some people in East Asia, where men have much less facial hair.
further to that then, if men in self some asian populaces have less facial hair, what selctively speaking may have caused their beards to “evolve” out of them.
I think in general it is the asian populace not specific to the hotter regions who have less facial hair
It’s not just those “not specific to the hotter regions”. Asians from Mongolia through Indochina and into southern Indonesia all lack significant beards to a greater or lesser extent. Native peoples of the Americas, being primarily Asiatic in descent also lack body hair form the Arctic circle through the equator and down to Tierra del Feugo.
And all the evidence suggests that you’ve got it back to front. It’s not that the beards ‘evolved out’ of some populations, it just evolved into some as Martin Hyde has already said. The original human populations were very likely beardless as is seen today on some of the San populations and various Asian populations. Exactly when and where beards first evolved and for what reasons is unknown. You could speculate endlessly
Bottom line: traits evolve “in” or “out” based on whether the trait affects the species’ survivability. IMHO, since beards are currently “neutral” - in the past, they might’ve provided warmth, now many men shave them off, but the beard’s presence - whether grown or shaved - does not affect the man’s ability to survive and procreate, so it will remain a trait.
I don’t mean to hijack too much, but what are the theories about why men evolved beards and women did not? I’m sure someone has a few.
The most likely reason for hairless faces to evolve would be sexual selection: women choosing beardless men to bear their children. Given that I have a beard, and my wife chose me to bear her 4 children, that seems unlikely to me. However, this is only a sample of one.
Seems unlikely to me too. Impossible even. 
Well, they weren’t all at once. It’s been over a period of some years.
Phew. I was thinking you must have some killer stretch marks had you borne them all at once.
In order for facial hair to evolve away, people with lots of facial hair need to stop breeding. (I am doing my part.)
But it looks like scruffy goatees are “in”, so this isn’t going to be the generation that makes enormous strides in that direction.
It would be very difficult for the human population, as it exists now, to lose a genetic trait such as facial hair. Forget for a moment that large groups of humans already have little to no facial hair-- there are still billions of humans who do. New traits evolve most easily in small, isolated populations. Large, stable, interbreeding popultions like we see in humans today tend to favor the retention of traits rather then the elimination of them. I can’t see a scenario that would wipe out facial hair unless it involved an **extremely **drastic reduction in population density.
Well, to give an analogy, Jews have been circumsized for thousands of years, and yet every Jewish boy is born with a foreskin.
Ed