Baldness American indians

[yon yonson]

is it possible that europeans are more susceptible to baldness because they were in generally colder and less sunny climates? maybe there was just no advantage for having lots of hair to block out the sun. i dont know, just an idea

[invisible]

is it possible that europeans are more susceptible to baldness because they were in generally colder and less sunny climates? maybe there was just no advantage for having lots of hair to block out the sun. i dont know, just an idea

Disagree, since the evolutionary purpose of hair on the head is to attract women.

I see plenty of bald men of all racial stock as well. Adoption of a SAD diet invariably increases baldness.

[TylerDurden]

Interesting take on evolution, but I don't think that neoteny is always considered an improvement. In my genetics classes there are examples of things developing further (more mature versions) as improvements, as well as immature versions being improvements. Like all evolution, there is no absolute forward or backwards, just what fits in the current environment best.

And as for baldness being neoteny, I don't buy it, since most bald men have hairy bodies. As a baby I had a full head of hair and no body hair, the exact opposite!

Evolution wouldn't necessarily involve losing hair all over the body, all in one go. There could be all sorts of reasons as to why, at first, most body hair was lost(our apemen ancestors were far hairier, in terms of body hair than us, for example), with baldness perhaps being the next evolutionary step that we're in the process of developing into.

As  for neoteny, it's the most likely explanation so far, at least as regards the evolution of humans and the growth of the brain, in particular. Indeed, some claim that humans are simply a neotenous version of chimps, more or less:-

http://en.wikipedia.org/wiki/Neoteny#Compared_to_other_species

I agree that increased maturity can also lead to  evolutionary advantages, but not necessarily of the kind that led to the increase in human brain-size or general human evolution.

[Raw Kyle]

The brain itself is the opposite of neoteny for humans, it is more developed than in other apes.

Also have you considered there is NO selective pressure for baldness? Without selective pressure there is NO evolution. Women do not like baldness, there is no increased reproductive rate in bald men, at best it's equal with men who do not go bald. It's probably a little lower. Therefore baldness does not fit the most important criteria for evolution, being something that builds up in the gene pool over time due to selective pressure.

[TylerDurden]

The brain itself is the opposite of neoteny for humans, it is more developed than in other apes.

Also have you considered there is NO selective pressure for baldness? Without selective pressure there is NO evolution. Women do not like baldness, there is no increased reproductive rate in bald men, at best it's equal with men who do not go bald. It's probably a little lower. Therefore baldness does not fit the most important criteria for evolution, being something that builds up in the gene pool over time due to selective pressure.

Not true. First of all, neoteny applies to the womb and early infancy. It's a fact that human babies' brains are much larger in proportion to the rest of their anatomy, than should normally be the case with adults(that's why humans have more problems giving birth). Secondly, there may well be an overall evolutionary advantage re losing body hair from all over(otherwise why did we lose the fur-like hair our apemen ancestors had?). It's just that baldness hasn't fully evolved yet as a trait, only partially, perhaps as the end of a long run of evolution causing hair-loss in the rest of the body.

Also, women do not necessarily discriminate against baldness. Indeed, various studies re this have shown that women find bald men more intelligent. Another point is that while baldness(or less hair in general) may be a positive trait, the fact that baldness is also a characteristic of older people in particular, might put off women, so that the evolutionary bonuses and negatives of being bald cancel each other out.

Another  point made by scientists is that evolution has stopped, for all intents and purposes, as we are no longer subject to natural selection, so that we can't strictly speaking, tell how much balder(or less bald) we would be in the future.

[wodgina]

I shave my head 'a number 1' we call it here so there's a few millimeters of hair.

I have to be careful though going out in the sun I've gotten sun stroke a few times because of a shaved head and it's not fun. Also you feel cold really easily. There's not many advantages of no hair.

[Guittarman03]

So why did we shed the bulk of our body hair?  I mean, we were in an ice age right?  Wouldn't more body hair have conferred a survival advantage?  Now that I think about it, we are one of the only mammal species that does not have a full coat - I mean, yes we have hair all over, but not like most other mammals. 

Does it have something to do with brain development?  Kind of like how gut size and brain size are inversely related?  Was it perhaps just a natural consequence of some other evolutionary development - in other words, would large amount of hair growth be a hindrance to some other sort of development that is particular to humans, or lightly haired mammals? 

[yon yonson]

i've read that we are generally hairless because it allows us to sweat and regulate body temperature better. this allows us to run for longer distances like for endurance hunting. that means that we probably evolved away from a full coat of hair while in a hotter climate like the out of africa theory suggests.

[Satya]

Or maybe it's because we started wearing the fur of other animals so we didn't need our own.  I think the aquatic ape theory says it's because we started hanging out in coastal regions and began swimming a lot.  There's a definite advantage to less hair there.  

But male pattern baldness is just head hair loss.  Like Kyle said, they often have hairy bodies.  I liked Yon Yonson's idea that baldness may have occurred to catch sun rays.  But it fails because it only happens in men (usually).  Plus the fact that the skin became lighter for that very fact.  Oh, and some animals can synthesize vitamin d on their fur, right?  Then they lick it off.  

My husband looks much like Lex, only younger.  He is a Scandinavian.  And I find him very sexy, so this idea that women don't like bald men is bunk.  Who knows, maybe they are better in bed?  They certainly produce a lot of offspring.

[Satya]

i've read that we are generally hairless because it allows us to sweat and regulate body temperature better. this allows us to run for longer distances like for endurance hunting. that means that we probably evolved away from a full coat of hair while in a hotter climate like the out of africa theory suggests.

Doesn't the fact that we are bipedal factor into this as well?  I forget.

[invisible]

Also have you considered there is NO selective pressure for baldness? Without selective pressure there is NO evolution. Women do not like baldness, there is no increased reproductive rate in bald men, at best it's equal with men who do not go bald. It's probably a little lower. Therefore baldness does not fit the most important criteria for evolution, being something that builds up in the gene pool over time due to selective pressure.

This I agree with, but baldness is not an evolutionary trait, and you can't really breed baldness out or in. Anyone can potentially go bald, just as anyone can potentially get cancer. A poor diet is the cause, but some get lucky and don't go bald or get cancer while eating crap their whole lives.

I believe hair on the head has the purpose to attract women, and people lose hair once their body percieves the time to reproduce has passed (hence body loses interest in preserving health and looking good) due to accelerated aging caused by toxins, sugars, excessive calories.

I started losing hair in my teens. Radically changing my diet made it stop and thicken a bit then remain steady. Unfortunately it didn't completely grow back (yet? hair cycles are qute long). I also had incredible severe acne, which RAF treated perfectly. Treatements that helped my skin also helped my hair (unless it was some horrible drug like Accutane, which doesn't help me but has others). Although the majority of diseases all share some common causes, acne, hairloss and diabetes are extremely closely tied.

[TylerDurden]

This I agree with, but baldness is not an evolutionary trait, and you can't really breed baldness out or in. Anyone can potentially go bald, just as anyone can potentially get cancer. A poor diet is the cause, but some get lucky and don't go bald or get cancer while eating crap their whole lives.

I disagree with the notion that you can't breed for baldness. Any such characteristic can be bred, it just takes careful genetic selection over some generations, much like with dogs.

Arguing that poor diet or disease is the cause of baldness yet claiming that "some people get lucky" is a contradiction in terms. I've known bald people in much better health than the rest of the population and people with luxuriant hair who've been in very poor health. Come to think of it, even most of the bald men I've come across haven't been at all hairy as regards the rest of their body.

[invisible]

not really a contradiction at all I think. Many people follow a SAD and die old and relatively healthy. Genetics determine how susceptible to a disease you are, diet determines if you actually get it. So not everyone is as likely to go bald. Someone might go bald being only slightly below perfect health, while another person would only go bald if they really abused their body to its limits. The same could be said about any condition though. However it seems that some people are REALLY susceptible to going bald. It doesn't take much to trigger hairloss compared to other problems.

Breeding out baldness would be like breeding out diabetes, or heat disease. Pretty impossible I think. Its not something like the colour of ones eyes.

[Guittarman03]

I was thinking, regarding balding and other differing traits; we question why did these traits evolve / how do they confer a survival advantage?  Seems like there are probably a few reasons for male pattern baldness:

-Poor diet, demanding environment, a consequence of an unhealthy lifestyle
-Complete genetic predisposition, regardless of diet/environment
-Everything else in between

Life survives b/c of it's great diversity.  Many different generations/lines of species develop many differing traits, some of which confer a survival advantage, some of which do not, but many of which are completely neutral.  This can change obviously with envirnmental changes (like the small deer/elk being more prone to survive b/c hunters go after the largest ones). 

So while hair loss is linked with poor health (real health, not just outside apparent wellness), this may always the case.  Entirely possible baldness just developed as one of those neutral forms of diversity.   

[TylerDurden]

The point is that baldness is not a disease but a physical characteristic. So, just as it is possible to breed humans to have 6 fingers on each hand or foot, so it is possible to breed people who have no hair on top of their heads.

Besides, the clincher is that there are plenty of wild animals who have bald heads, but live on raw, healthy diets without any issues.

[invisible]

The point is that baldness is not a disease but a physical characteristic.

If that were true then there would be no connection between insulin, fat intake, hormonal imbalance and hair loss. Hair loss is treateable by improving things that are known to impact overall health, therefore its likely a disease.

Hairloss treatement drug propecia stops the conversion of DHT from excessive free testosterone. This excessive unused testosterone in the body is not healthy or simply a characteristic of the body.

[TylerDurden]

Hormones affect almost everything in the body, so it's unsurprising that it would affect hair-growth or hair-loss(hair is after all detachable from the body, unlike arms/legs).

[wodgina]

Hair on our heads helps keeps us cool and keeps us warm. How can losing it not be a bad thing?

[TylerDurden]

Well, judging from my experience, hair on the head definitely does not keep me cool, it makes me hot(I always do a grade 1 or 2 haircut in the summer because of this).

[wodgina]

Do you mean standing out in direct sunlight? I spend a lot of time surfing and in the outdoors and hair does keep you cool when in direct light. I have to be careful surfing with a shaved head because I get sunstroke. Yes in the shade short hair keeps you cool or maybe in Europe where the sun isn't so strong.

[TylerDurden]

Do you mean standing out in direct sunlight? I spend a lot of time surfing and in the outdoors and hair does keep you cool when in direct light. I have to be careful surfing with a shaved head because I get sunstroke. Yes in the shade short hair keeps you cool or maybe in Europe where the sun isn't so strong.

The longer my hair is the hotter I feel, regardless of whether I'm in the shade or in the sun. And in some parts of Europe such as Italy, Spain and Greece, it can get extremely hot in the summer. The only time I get respite in the summer with anything more than a grade 2 is if I soak my hair in water, but that doesn't last, of course.

[Raw Kyle]

If full heads of hair didn't help being in hot weather I wonder why Aborigines always had them.

[TylerDurden]

If full heads of hair didn't help being in hot weather I wonder why Aborigines always had them.

To diwht sunstroke susceptibility? Like I said because humans are neither all completely bald or completely hairy, there may well be competing evolutionary trends in whixh some involve baldness being a positive evolutionary trair and others involve baldness being a negative evolutionary trait.

[William]

If full heads of hair didn't help being in hot weather I wonder why Aborigines always had them.

No barbers, that's why.  
They don't have beards either ("barber" comes from the word for beard), and their females are different too, they have pubic hair more like beaver fur than anything else.

IMO hair does help in hot sunny weather; IIRC European climate is more often overcast and miserably wet than N. America.

This makes me think that the theory of polygenesis is credible, compared to the African origin hypothesis.

[Raw Kyle]

To diwht sunstroke susceptibility? Like I said because humans are neither all completely bald or completely hairy, there may well be competing evolutionary trends in whixh some involve baldness being a positive evolutionary trair and others involve baldness being a negative evolutionary trait.

My question of selective pressure still remains. In order for baldness to have gone into the gene pool as you claim as a possible evolutionary change, there must have been selective pressure for it. I think we can all agree that the average woman prefers their men to have a full head of hair over partially or fully bald, that alone points to no selective pressure. Unless you can show somehow that bald men have more reproductive success, or rather had more reproductive success in the preceding generations when baldness started (you would have to figure that out too) to get us where we are now of many men going bald later in life, then it's just not evolution.

Also why would it only happen to men as they age? If it's an advantage and a genetic change rather than a breakdown of hair follicles from faulty nutrition, I would imagine it would be present at birth and they wouldn't go through the normal cycle of growing full heads of hair in their adolescence and early adulthood.

Looking at all the factors I think it's unreasonable to say it's more likely for baldness to be an evolutionary trait rather than just the effect of faulty nutrition. Yes some gene pools tolerate this faulty nutrition for this trait better (Asians in particular) but that doesn't make it genetic, it just makes it like everything else in that your genes determine how faulty nutrition will affect you. That would be like saying because Asians have less colon cancer than Europeans that it's a genetic disease rather than a disease of nutrition. Every disease the modern SAD or grain heavy diet causes affects different gene populations differently, still nutrition is the cause not their faulty genes.