Anyone got any evolutionary theories for hairloss?

[Bryan]

Considering science does not know for sure how life started, or what caused evolution who is to say there even is a reason? I mean it might just be some anomaly or fluke mutation that might not ever happen again or in any pattern.

Well, you're missing an important point: balding apparently evolved independently in a few different primate lines. What is the chance of such a "fluke mutation" occurring like that more than once in different species? :wink: Maybe the evolutionary pressure for finding additional ways to cool the brain is stronger than we think.

BTW, Doctor, I'm really curious to see what you think of the Cabanac paper. If you can't find it in your local medical library, I'd be happy to send you a copy of it. Just PM me your snail-mail address.

Bryan

 

[docj077]

Considering science does not know for sure how life started, or what caused evolution who is to say there even is a reason? I mean it might just be some anomaly or fluke mutation that might not ever happen again or in any pattern.

Well, you're missing an important point: balding apparently evolved independently in a few different primate lines. What is the chance of such a "fluke mutation" occurring like that more than once in different species? :wink: Maybe the evolutionary pressure for finding additional ways to cool the brain is stronger than we think.

BTW, Doctor, I'm really curious to see what you think of the Cabanac paper. If you can't find it in your local medical library, I'd be happy to send you a copy of it. Just PM me your snail-mail address.

Bryan

Do you have the title of the paper? There are a lot of Cabanac papers and I'm not sure which one you're referring to. I might be able to find it at my library or online.

 

[S Foote.]

Tell us all the purpose of androgens "directly" growing armpit hair?

Shave your armpits and prevent sebum production with a topical anti-androgen for a few weeks. Then, you'll see the purpose of sebum production and underarm hair. I have to warm you. Make sure you have some lotion on hand for the chafing.

That just doesn't make any sense in terms of either the real world experience, or the subject we are discussing which is purpose in evolution.

I don't see all the kids complaining about sore arm pits, does anyone else? So your whole notion is wrong at the basic level.

One other clear example of an actual evolutionary disadvantage of a direct androgen stimulation of hair growth, is pubic hair. The developement of pubic hair particularly in women, can increase risk of infections. So why would nature evolve a "direct" effect that carries a risk?

In fact the only hard in-vitro evidence we have, clearly shows that androgens do "NOT" directly change any pre-existing kind of hair growth. Androgens do "NOT" directly convert normal scalp follicles into male pattern baldness follicles!

This is something that is well known and numerous studies have been posted on this site that refute what you say. Growth inhibition requires androgen binding at the level of the dermal papillae, as well as, at the level of the dermal fibroblasts at concentrations that are equivalent to body growth factor and hormone levels in individuals with male pattern baldness. Increasing testosterone levels incrementally will eventually lead to growth inhibition of hair follicles from areas that are considered to be immune to such processes such as follicles taken from the back of the head.

That is pure speculation on your part.

Are you saying as Bryan claims that exposure to androgens over a period of time is required before follicle cells become sensitive "TOO" androgens? If so you also have to believe that each individual follicle has a different threshold at which they "then" become directly sensitive to androgens?

Because if so, you are required to prove that there really "are" a number of pre-existing differences in follicles before androgens come into the equation?

It's very easy to make assumptions, but the only hard evidence we have to date clearly shows androgens are not "directly" causing any changes in the pre-existing growth characteristics of any kind of follicle cell.

Also in terms of the evolutionary question, why should all these alledged differences in follicle sensitivity, and opposite priming to direct actions of androgens have evolved?

There is no justification for such a thing in evolution, it makes no sense at all!

The only mechanism that makes sense of this in terms of mammalian evolution, is that androgens are changing the local tissue "Hydraulics" in line with the dermal model in my early paper.

S Foote.

However, in order for your mechanism to work there is the requirement of muscle hypertrophy in the scalp, which is not a proven phenomenon. The effect must lead to lymphatic obstruction, which is not a proven phenomenon either. Looking at histological specimens from men with male pattern baldness reveals neither process. Nor, is there any evidence for edema of any kind. And, the argument that the edema is so little that it can't be seen doesn't work here. In other parts of the body where edema can lead to hair loss, the edema is always very prevalent before any other process begins.

Another problem that I have here is that there is no increase in the incidence of lymphangiosarcoma in the scalp of men with male pattern baldness. That's a big problem, because lymphatic obstruction has a tendency to lead to such processes. Just ask women that have gone through radical mastectomies.

Histologic specimens also fail to show lymphatic dilation or proliferation of any sort.

The last item that must be considered is the very mechanism that minoxidil uses to decrease blood pressure. Minoxidil is a selective arterial dilator. It would increase blood flow to the scalp, and thus, increase edema if there is indeed a failure of lymphatics.

Your theory is interesting Foote, but I have too many problems with it. Both in terms of the histology and pathology and in terms of the use of minoxidil for male pattern baldness.

You are just so wrong in your interpretation of the scientific information, that it is pointless trying to debate these points with you. Just one example is your claim about Minoxidil above. the NOX in MiNOXidil refers to its effect upon the NO2 pathway, that is known to increase lymphatic efficiency in studies.

http://www.ncbi.nlm.nih.gov/entrez/quer ... s=15192027

http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract



Also Minoxidil is known to shift fluid volume to the central core, that is away from the surface tissues and hair follicles.

http://www.hairsite4.com/dc/dcboard.php ... 051&page=2


S Foote.

 

[S Foote.]

Considering science does not know for sure how life started, or what caused evolution who is to say there even is a reason? I mean it might just be some anomaly or fluke mutation that might not ever happen again or in any pattern.

Well, you're missing an important point: balding apparently evolved independently in a few different primate lines. What is the chance of such a "fluke mutation" occurring like that more than once in different species? :wink: Maybe the evolutionary pressure for finding additional ways to cool the brain is stronger than we think.

BTW, Doctor, I'm really curious to see what you think of the Cabanac paper. If you can't find it in your local medical library, I'd be happy to send you a copy of it. Just PM me your snail-mail address.

Bryan

Do you have the title of the paper? There are a lot of Cabanac papers and I'm not sure which one you're referring to. I might be able to find it at my library or online.

This is the abstract:

Eur J Appl Physiol Occup Physiol. 1988;58(1-2):39-46.
Beards, baldness, and sweat secretion.

Cabanac M, Brinnel H.

Universite Laval, Faculte de Medicine, Department de Physiologie, Quebec, Canada.

The hypothesis according to which male common baldness has developed in the human species as a compensation for the growth of a beard in order to achieve heat loss has been tested. In 100 clean-shaven men direct measurement of the area of glabrous skin on the forehead and calvaria was found to be proportional to that of the hairy skin on the lips, cheeks, chin and neck. During light hyperthermia the evaporation rate on the bald scalp was 2 to 3 times higher than on the hairy scalp. Conversely the evaporation rate was practically equal on the foreheads and chins of women and unbearded young men, while in adult clean-shaven bearded men it was 40% less on the chin than the forehead. These results support the hypothesis that male baldness is a thermoregulatory compensation for the growth of a beard in adults.

online pharmacy ref. source: http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract



S Foote.

 

[Bryan]

Every aspect of my theory can be shown to have both purpose in evolution, and precedent in already recognised phisiological mechanisms.

[...] In fact the only hard in-vitro evidence we have, clearly shows that androgens do "NOT" directly change any pre-existing kind of hair growth. Androgens do "NOT" directly convert normal scalp follicles into male pattern baldness follicles!

In order to try to get around this hard proven fact, completely unprecedented hormone "time delay" mechanisms are invented by unscientific people :wink:

Stephen, you are a FLAMING HYPOCRITE!!

I may not be able to explain the "genetic switch" hypothesis to your satisfaction (who COULD?), but then neither can YOU provide an explanation for how contact inhibition could change a cellular response to androgens from stimulation to suppression. I've asked you repeatedly to give me another biological precedent for that occurrence, and you have utterly failed. You haven't given me so much as a single example.

So get on your knees as I raise you to the Knighthood of Disingenuousness: (touching the royal sword to both your shoulders, in turn) I now pronounce you Sir Flaming Hypocrite!! You will now travel about the land, refusing to answer pointed questions!

If as you claim here, follicles in the male pattern baldness area have evolved to be directly shrunk by androgens for cooling purposes along with beard growth, why aren't "ALL" men capable of growing a beard then bald??

Quit trying to make it so black-and-white. It's just a tendency in that direction. It doesn't mean that if you grow a beard, you're automatically DOOMED to start losing your scalp hair!

How come beard developement in men is not directly corelated with scalp hair loss? If it's evolved because it is important in human survival, brain cooling wise, there would be a clear link in the timeframe!

I think it's only just begun, evolutionarily speaking. I think it's probably inevitable that balding will more and more take over in our species (and probably other primate species, too) as the eons go be. I think humankind is going to end up looking like the "Grays" of popular lore! :lol:

Bryan

 

[DammitLetMeIn]

Well, balding is a sign of aging.

This is universally accepted in all primates.

Perhaps all balding humans have done is speeded up the aging process in some way...

 

[S Foote.]

Every aspect of my theory can be shown to have both purpose in evolution, and precedent in already recognised phisiological mechanisms.

[...] In fact the only hard in-vitro evidence we have, clearly shows that androgens do "NOT" directly change any pre-existing kind of hair growth. Androgens do "NOT" directly convert normal scalp follicles into male pattern baldness follicles!

In order to try to get around this hard proven fact, completely unprecedented hormone "time delay" mechanisms are invented by unscientific people :wink:

Stephen, you are a FLAMING HYPOCRITE!!

I may not be able to explain the "genetic switch" hypothesis to your satisfaction (who COULD?), but then neither can YOU provide an explanation for how contact inhibition could change a cellular response to androgens from stimulation to suppression. I've asked you repeatedly to give me another biological precedent for that occurrence, and you have utterly failed. You haven't given me so much as a single example.

So get on your knees as I raise you to the Knighthood of Disingenuousness: (touching the royal sword to both your shoulders, in turn) I now pronounce you Sir Flaming Hypocrite!! You will now travel about the land, refusing to answer pointed questions!

You can use all the verbal distractions you like Bryan, you are not fooling anyone who has followed our previous debates 8)

I "HAVE" provided you with the known precident for that "switch" many times, so your continued claim that i have not just shows your a liar :wink:

The in-vitro studies clearly show that it is androgen inducable TGF beta-1 that is implicated in those particular studies. Prior contact inhibition is known to effect the same genes implicated in the TGF beta-1 pathway.

So there is clear precident for prior contact inhibition to influence a "switch" in the expression of TGF betga-1.

http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract

Now just try to allow this precedent to enter your thick skull, and stop lying on these forums claiming i have not referenced this before! :roll:

You have no precedent at all for your genetic "clock" claims, and in fact all the hard evidence about known hormone/cell interactions disproves this already!

You may want to Knight me with a title, but you are clearly the court jester Bryan 8)

If as you claim here, follicles in the male pattern baldness area have evolved to be directly shrunk by androgens for cooling purposes along with beard growth, why aren't "ALL" men capable of growing a beard then bald??

Quit trying to make it so black-and-white. It's just a tendency in that direction. It doesn't mean that if you grow a beard, you're automatically DOOMED to start losing your scalp hair!

So yet another u turn then Bryan :roll:

Earlier in this thread you clearly tried to claim that a direct action of androgens on follicles, was in line with a brain cooling requirement. But you can't answer the evidence to the contrary, so this is now only a "tendency".

Pretty pathetic turn around even by your standards :roll:

It is late here now, and i will be away for the next few days. So you should take the chance to come up with some better excuses for your scientificaly unsupported opinions, when i return :wink:

S Foote.

 

[docj077]

Considering science does not know for sure how life started, or what caused evolution who is to say there even is a reason? I mean it might just be some anomaly or fluke mutation that might not ever happen again or in any pattern.

Well, you're missing an important point: balding apparently evolved independently in a few different primate lines. What is the chance of such a "fluke mutation" occurring like that more than once in different species? :wink: Maybe the evolutionary pressure for finding additional ways to cool the brain is stronger than we think.

BTW, Doctor, I'm really curious to see what you think of the Cabanac paper. If you can't find it in your local medical library, I'd be happy to send you a copy of it. Just PM me your snail-mail address.

Bryan

Do you have the title of the paper? There are a lot of Cabanac papers and I'm not sure which one you're referring to. I might be able to find it at my library or online.

This is the abstract:

Eur J Appl Physiol Occup Physiol. 1988;58(1-2):39-46.
Beards, baldness, and sweat secretion.

Cabanac M, Brinnel H.

Universite Laval, Faculte de Medicine, Department de Physiologie, Quebec, Canada.

The hypothesis according to which male common baldness has developed in the human species as a compensation for the growth of a beard in order to achieve heat loss has been tested. In 100 clean-shaven men direct measurement of the area of glabrous skin on the forehead and calvaria was found to be proportional to that of the hairy skin on the lips, cheeks, chin and neck. During light hyperthermia the evaporation rate on the bald scalp was 2 to 3 times higher than on the hairy scalp. Conversely the evaporation rate was practically equal on the foreheads and chins of women and unbearded young men, while in adult clean-shaven bearded men it was 40% less on the chin than the forehead. These results support the hypothesis that male baldness is a thermoregulatory compensation for the growth of a beard in adults.

online pharmacy ref. source: http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract



S Foote.

That's actually quite interesting. Why would male pattern baldness be the compensatory mechanism? This sort of evaporation should only be needed during times of increased heat and stress such as the summer. However, the need for hair to maintain scalp and calvarial temperature seems far more important for me. Especially, as humans have migrated from the equator towards the higher latitudes.

If what they say is true, then male pattern baldness is the result of a mutation that would have occurred before homo sapiens migrated. But, what I don't understand is why the mutation hasn't been lost or at least reduced as colder climates were encountered.

It's a good theory, but it makes male pattern baldness synonymous with the continued presence of the appendix. A vestigial organ or process that has no real impact on modern individuals beyond the scope of equatorial living.

 

[Bryan]

That's actually quite interesting.

It IS interesting, isn't it?

Why would male pattern baldness be the compensatory mechanism? This sort of evaporation should only be needed during times of increased heat and stress such as the summer. However, the need for hair to maintain scalp and calvarial temperature seems far more important for me. Especially, as humans have migrated from the equator towards the higher latitudes.

If what they say is true, then male pattern baldness is the result of a mutation that would have occurred before homo sapiens migrated. But, what I don't understand is why the mutation hasn't been lost or at least reduced as colder climates were encountered.

I imagine it probably HAS been reduced (at least somewhat) as colder climates have been encountered by humans. After all, male pattern baldness isn't (yet) a universal phenomenon.

Bryan

 

[docj077]

http://www.ncbi.nlm.nih.gov/entrez/quer ... s=15192027[/url]

http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract



Also Minoxidil is known to shift fluid volume to the central core, that is away from the surface tissues and hair follicles.

http://www.hairsite4.com/dc/dcboard.php ... 051&page=2


S Foote.[/quote:ee1c4]

Why are such debates pointless? I fail to understand such reasoning. Minoxidil is indeed a selective arterial dilator. If it does increase NO, then I'd like to truly know what the effect is on lymphatics. Lymphatics at the level of the hair follicle don't have anything put endothelial cells lining them. They can't expand or contract unless the muscles around them allow them to do so, because they don't have a muscular layer in order to change their diameter. NO should have no real effect at this level, because there is nothing to affect.

I'm sorry, but I just can't accept that as the mechanism of action of minoxidil. Especially, with the recent discovery of its effect upon TGF-beta and keratinocyte apoptosis.

Also, if minoxidil is shifting fluid aware from peripheral tissues, then it should also shift nutrients aware from that area decreasing the available nutrients for the follicles. That seems to be a negative result.

 

[docj077]

That's actually quite interesting.

It IS interesting, isn't it?

Why would male pattern baldness be the compensatory mechanism? This sort of evaporation should only be needed during times of increased heat and stress such as the summer. However, the need for hair to maintain scalp and calvarial temperature seems far more important for me. Especially, as humans have migrated from the equator towards the higher latitudes.

If what they say is true, then male pattern baldness is the result of a mutation that would have occurred before homo sapiens migrated. But, what I don't understand is why the mutation hasn't been lost or at least reduced as colder climates were encountered.

I imagine it probably HAS been reduced (at least somewhat) as colder climates have been encountered by humans. After all, male pattern baldness isn't (yet) a universal phenomenon.

Bryan

You have a poin there about it not being a universal phenomenon. Obviously, the response to androgens in the body is one that worries me. Afterall, 80% of men that reach the age of 80 will develop prostate cancer. What is the percent of men with noticable male pattern baldness? 60% or so. I've heard upwards of 80%, but that might have been on some crazy website somewhere.

I wonder if androgen insensitivity and male pattern baldness is more common in people from warmer or colder climates in terms of migratory patterns within the last few thousand years.

 

[Jacob]

Considering science does not know for sure how life started, or what caused evolution who is to say there even is a reason? I mean it might just be some anomaly or fluke mutation that might not ever happen again or in any pattern. I mean lightning strikes in totally random places that can not be predicted in any way known to man. Who is to say that some natural processes like evolution have any predictable path? People want these things to make logical sense when mother nature just does as it wants irrespective of what we want to believe. Its funny how researchers apply math to solving problems in the human body when math makes no sense in the human body because math was really not invented to be applied to that.

Evolution is just a theory..don't forget :roll:

 

[Bryan]

Evolution is just a theory..don't forget :roll:

Not really.

 

[Jacob]

Yes it is.

 

[DammitLetMeIn]

Yes it is.

Hmm, nah, not really...

 

[hair today gone tomorrow]

to an extent it is just a theory...like saying humans evolved from single cell organisms is a theory...but evolution within a species is not a theory.

 

[Jacob]

Yes it is a theory.

I used to "debate" in creation/evolution forums. The one thing I used to ask that nobody could back up..was..show me the transitional fossil record on anything. Not pictures or drawings..which is what they would start posting. The actual fossil record- photographs.

 

[powersam]

thats really not needed though jacob. as you have real life examples of a species now separated in location, being totally changed in appearance and function. essentially a different species now.

one example of this would be the lion and the tiger. they can still breed, although the result will be sterile. yet they are extremely different in appearance, behaviour and function. a result of natural selection and random mutation.

there are holes in evolutionary theory yes, but it those holes dont discount it.

one thing i think is also worth mentioning: wikipedia

"The word theory has a number of distinct meanings in different fields of knowledge, depending on their methodologies and the context of discussion.

In science, a theory is a mathematical description, a logical explanation, a verified hypothesis, or a proven model of the manner of interaction of a set of natural phenomena, capable of predicting future occurrences or observations of the same kind, and capable of being tested through experiment or otherwise falsified through empirical observation."

 

[Bryan]

I may not be able to explain the "genetic switch" hypothesis to your satisfaction (who COULD?), but then neither can YOU provide an explanation for how contact inhibition could change a cellular response to androgens from stimulation to suppression. I've asked you repeatedly to give me another biological precedent for that occurrence, and you have utterly failed. You haven't given me so much as a single example.

I "HAVE" provided you with the known precident for that "switch" many times, so your continued claim that i have not just shows your a liar :wink:

Sorry, Stephen, but I'm going to show everyone just who the "liar" is here.

The in-vitro studies clearly show that it is androgen inducable TGF beta-1 that is implicated in those particular studies. Prior contact inhibition is known to effect the same genes implicated in the TGF beta-1 pathway.

Possibly, but that ain't what I asked you for. I asked you to provide me an example, ANY example, of contact inhibition altering the way that a cell responds to androgens. GIVE ME WHAT I ASKED YOU FOR, and quit trying to fool everybody by changing the subject to something entirely different.

So there is clear precident for prior contact inhibition to influence a "switch" in the expression of TGF betga-1.

http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract

The word "androgen" doesn't even APPEAR in that abstract, dumbbell! You're giving me NOT what I asked for, but something only very very tangentially related, hoping that everybody would think you've answered my challenge! If the word "androgen" doesn't even appear in that abstract, then how could that be an example of contact inhibition altering the way that cells respond to androgens??

Now just try to allow this precedent to enter your thick skull, and stop lying on these forums claiming i have not referenced this before! :roll:

OH REALLY?? Who's the liar NOW?? :lol:

[quote="S Foote.":6bd29]If as you claim here, follicles in the male pattern baldness area have evolved to be directly shrunk by androgens for cooling purposes along with beard growth, why aren't "ALL" men capable of growing a beard then bald??

Quit trying to make it so black-and-white. It's just a tendency in that direction. It doesn't mean that if you grow a beard, you're automatically DOOMED to start losing your scalp hair!

So yet another u turn then Bryan :roll: [/quote:6bd29]

How is that a "u-turn"?

Earlier in this thread you clearly tried to claim that a direct action of androgens on follicles, was in line with a brain cooling requirement. But you can't answer the evidence to the contrary, so this is now only a "tendency".

What "evidence to the contrary" are you talking about?

It is late here now, and i will be away for the next few days.

Don't worry, this post will be waiting for you when you come back! It's not going away, unfortunately for you! :wink:

Bryan

 

[Jacob]

Of course it's not needed when it can't be shown. :roll: The fact is..there are no such fossil records on ANYTHING.

There are some misconceptions about what those of us believe when it comes to things like you suggest- lions and tigers. Here are a couple of links: http://www.answersingenesis.org/creatio ... lphins.asp

This is from another page there but summarizes it pretty good:

The pictures [available only in Creation magazine] show dad lion, mum tigress and ‘liger’ cubs. Since the pair came together in 1997 in the Samsung Everland safari park in South Korea, they have produced 17 cubs.1 Such hybrids probably do not occur in the wild, largely because lions and tigers do not live in the same areas. Ligers grow to become the largest cats in the world—up to half a tonne in weight—bigger than either parent. Did God create lions and tigers separately on Day 6 of Creation Week? That they readily hybridize suggests that lions and tigers may have descended from the same original created kind—just as chihuahuas and great danes have both been bred from an original wolf kind. Female ligers can often mate successfully with a lion or a tiger, but male ligers are apparently infertile.2

I'm glad you called it a theory though.

BTW..here's an interesting article I read recently: http://www.answersingenesis.org/docs200 ... tissue.asp

It reminds me of a certain pine tree thought extinct for "millions of years". It was recently found again...looks the same as the fossils of them. That particular one just happened to not "evolve" all these millions of years 8)