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Author Topic:   the evolution of clothes?
Abshalom
Inactive Member


Message 121 of 161 (180195)
01-24-2005 11:18 AM


The Naked Truth?
Okay, so let's look at HAIR RETENTION rather than hair loss.
I'm going to skip pubic hair and underarm hair for the moment.
Eyebrows: Male and female both retain eyebrows, although they appear to become very much more bushy in aging men than aging women. Are eyebrows retained to shield the eyes from sunlight, and does the increased bushiness correspond with decreased eyesight or increased sensitivity to light?
Mustaches: Assuming the mustache serves the same function in both male and female humans (to protect the sensitive lip tissue from sunlight), why is it more pronounced in men than women? Is this a "sexual attraction" thing? Is this a "hunter vs. homemaker" deal?
Facial hair in general: Same questions. Is it to protect the hunter from wind chafing, provide more insulation, etc.? Is its much lower growth and less coarse texture in women associated with sexual attraction or is it responsive to the working environment of the sexes?
I know about testosterone, etc.; but why is that applicable in humans but not in other mammals? Female primates, in particular apes like gibbons, gorillas, and chimps, don't appear any less hairy than males do they (except for the genitalia as pointed out during estrus)?
So, what's the bare naked truth about the disparity of the degree of hairiness in humans re: male/female or between "races" for that matter?

contracycle
Inactive Member


Message 122 of 161 (180216)
01-24-2005 11:33 AM
Reply to: Message 109 by RAZD
01-21-2005 11:13 PM


Re: And the winner is ... (can I have the envelope please ...)?
quote:
What it supports is that upright posture evolved before the savannah ecosystem was involved. Now let us remember that the savannah was seen as the reason for standing, and this has been refuted.
was it now? I'm in the camp tyhat sees upright posture as pretty unremarkable in brachiating animals and as developed for tool use.
quote:
It would be interesting to see just how significant your factor is. My argument (to refresh your memory again) is that it is relatively minor as things go in the selection of bareness, that other factors are also likely to be involved and that a major one is sexual selection.
Yes, so you claim. Unfortuntaley this leaves us with no explanation at all for humans remarkable running abilities - able to outdistance almost everything in the long haul. This is fundamenatally why a sexual selewction hypothesis is much weaker - it proposes that these unique and dramatic features occur by accident rather than adaptation. If thats the case then what features cannot be reduced to sexual selection, and what does sexual selection mean? Nothing.
quote:
And the same holds for the body. You are saying {X} works on the head area and {notX} works on the rest of the body. Explain again how this is logical?
Now you're playing dumb. I have already explained the physics to you.
X works on the head becuase it is where most of the suns energy will be felt most consistently, and becuase we do NOT want the big blood vessels in the head to be more heated; we want them to output hit. Hence, shielding.
This cannot be inexplicable to you as you pretend, otherwise thick soles would also appear you if seen on the feet. Afteer all, if normal skin is good enough for the main body, surely it shoyuld be good enough for the soles too. Right? Stop playing silly buggers.
quote:
So you agree that the point I raised {{ You also have the problem of the sweatiest parts of the body still being endowed with thick hair: pits and pubics. And as pits are already in the shade you cannot play the shade card here.}} is valid as a challenge to your hypothesis and that you have not refuted it?
Unfortunately for you I have refuted it. Your argument is that if the running ape thesis is valid at all, tyhere should be no exceptions to hair loss anywhare. This is manifestly ridiculous, an extension to an illogical extreme. And all I have to do is provide one plausible reason why patches of hair may be retained to destroy your overextension. Which I have done.
quote:
It is obvious, to me anyway: Long hair demonstrates that run-away sexual selection has occurred in humans. It is that simple. But it is not the only feature that is like this, there are quite a number of them. More on this later.
Ahahaha. So now your argument is reduced to claiming that because there has been SOME sexual selction, there CANNOT be any other adaptations? Illogical.
quote:
But you have yet to demonstrate that this is reasonable in any way for it to be that fundamental. You have no other examples at all where this also holds true, and the pattern of human bareness is not consistent with the hypothesis, either in where on the human body hair remains or in the sexual dimorphism of this feature versus {ability/roles}. Men run faster than women, men are bigger than women, and men are hairier than women. It doesn’t add up.
Nonsens. Humans are DEMONTRABLY better long distance runners than many or even most animals. The pattern of hair retention fits my model perfectly, especially the retention of head hair, which my model predicts. Any notional sexual dimorphism issue can easily be addressed by positing that remnants of hair remain as armour - thus, on males, we quite spectacularly have our necks still shielded by a matte of hair, and we do NOT lose this in old age.
Men may run FASTER than women but I never argued about speed, only DISTANCE. Males have all the usual combat features - bigger frame, more muscular, more armoured. But in our case our quite small degree of dimorphism may arise precisely becuase these features cause necessary compromises with the major adaptation - running.
quote:
Now explain the relevance of whale baleen to the specific selection of fine hair within the human species again please?
If tyou like I shall repeat myself: to demonstrate that your assertion that hair is only ever modifvied by sexual selection is false. Done and dusted.
quote:
And yet arabian horses do not have less hair or finer hair than those donkeys do they? Again there is a complete absence of the trend you claim to be fundamental in other species.
Umm, yes I believe there is. But if you need a more extreme variation, look at steppe ponys adapted for cold envrionments - thick bushy hair. I am pointing to a fundemanetal feature of temperature regulation that is addressed in all animals in all environments. Lowland cows are less hairy than highland cows. Plains dogs are less heavily coated than sub-arctic dogs. This is hardly some sort of obscure and unreasonable suggestion.
quote:
Fitness for breeding. It still comes down to sexual arousal. The problem with a very sophisticated degree of UNconsious recognition is the same as the problem with intelligent design — there is no mechanism for it to operate and no evidence of it operating, and now you are talking about specimen {B} being ugly ... LOL. Nor can your very sophisticated degree of UNconsious recognition differentiate between recognition of sexual feedback mechanisms and recognition of running ability.
Hahahah.... OK then, I'm going to enjoy this: would you like to explain how sexual fitness os recognised? I'm all ears. This is a guenuine question - human cognition is quite fascinating. My explanation shows how and why a feature might be perceived as attractive; according to your argumentm, there is no way to determine what is attractive from what is not, is there. Take it away.
[quote] My desperation? LOL. No the display of male leg and bare chest and other aspects is exactly what I was referring to here.[/qupte]
Umm, no you were not - ebcuase you can't explain why they are sexy.
quote:
If you recall I said that song and dance were part of the mating ritual that resulted in the runaway sexual selection of certain features, like complex language, costume, creativity, dancing legs, and ... bare skin.
Which is like appealing to intelligent design - in the lack of any other explanation, it MUST have been sexual! Catch me before I fall, matron. It remains a non answer.
quote:
Because they are Alpha Males? ROFLOL. They are alpha because they are rock stars, not rock stars because they are alpha.
Thats what I said. The very social respect they command makes them so.
quote:
They are rock stars because they can sing and dance and display creativity and show off a lot of bare body and moving booty in a creative, entertaining and attraction gathering way.
Can you cite any other animal that does these things? Becuase as they ALL arise from sexual selection, one would expect them to arise consistently, no?
quote:
I am running out of laughter here. Marathon runners don’t have groupies because they are not sex symbols.
Yes - you are failing to challenge my points, you know.
quote:
The dancing skill of soccer players goes back (once more) to the mating ritual dancing ...... not to the running skill: just look at the game highlights eh?
No no noot - tha dancing skills display their running competence, geddit?
Now lets take another look at your "summary"
RUNNING:
* cannot explain long hair on head
... but does not contradict it
* cannot explain hair in high sweat armpits
... but does not contradict it
* cannot explain hair in high sweat pubic area
... but does not contradict it
* cannot explain hair on high sweat area of male only face
... explained through standard combat adaptaion, running model reinforced
* cannot explain greater variation of hairiness in males
... cannot explain varying height in either sex aither. Duh. Natural variation is sufficient.
* cannot explain greater average hairiness of males
... explained above, does not contradict model
* cannot explain virtual lack of sexiness of running stars
... but does explain the sexiness of dancers and leg/foot fetishism
* cannot explain why the larger and faster male is hairier than the female
... you're repeating yourself, this is twice answered above
* cannot explain actual sexiness of singing and dancing stars
... becuase RAZD cannot read. Rock stars are only sexy becuase of TV.
* cannot explain that singing and dancing stars do not look like runners
... becuase they are not directly relevant
* cannot explain actual sexiness of naked and shaved porn stars
... does, becuase hairlessness has survival value
* cannot explain that porn stars do not look like runners
... RAZD becomes possibly absurdist. They are sexy by standard running ape standards.
* cannot explain the virtual lack of any similar {hair\fur} trend in other species, even ones larger than humans that run in a hot environment, as should be predicted (or at a minimum, not be unexpected) if it is survival selection related to natural variation in {hair\fur} density.
... displays startling ignorance of the easily observed and much studied heat dissipation mechanisms in all ammalls, aquatic or terrestrial. the pattern of heavier fur toward the poles and thinner, lighter fur toward the equator is undeniable.
... RAZD is therfore
quote:
Absurd -

This message is a reply to:
 Message 109 by RAZD, posted 01-21-2005 11:13 PM RAZD has replied

Replies to this message:
 Message 123 by RAZD, posted 01-25-2005 1:27 AM contracycle has replied

RAZD
Member (Idle past 1654 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 123 of 161 (180374)
01-25-2005 1:27 AM
Reply to: Message 122 by contracycle
01-24-2005 11:33 AM


Re: And the winner is ... (can I have the envelope please ...)?
contracycle writes:
Unfortuntaley this leaves us with no explanation at all for humans remarkable running abilities - able to outdistance almost everything in the long haul.
You are conflating two different arguments. Why should sexual selection explain a survival feature? Do male peacock tail feathers explain the remarkable ability of peacocks to fly or walk or crow? This is as irrelevant as the baleen example to my position. For the record I have noted before it takes the human tracking ability and the conscious behavior to not exhaust oneself in the running, and that is sufficient to differentiate human behavior from other animals in that particular behavior. Whether that behavior can then be the basis for bareness rather than just the usual long limbs and good lungs of all other running animals has not been shown.
Run the experiment as I outlined and see what the results are. Until then, you don't have any basis for your claim, or your insults, or your false strawmen arguments and ridiculous non-sequiturs, or your unwillingness to look at other information. Especially when you repeat the strawmen arguments when they have been shown to be false representations. Sorry, but I expected better.
Most of your post is just a repeat of past errors with a couple of new conjectures thrown in. I see no need to repeat correcting your mistakes again, as you seem unable to learn from them at this point. The whale baleen issue is a case in point of such a repeated error.
The pattern of hair retention fits my model perfectly, especially the retention of head hair, which my model predicts.
This is new: your model of hair loss for greater cooling now predicts that human head hair is the longest hair in the ape kingdom, to the point where it completely covers many areas that are supposedly bared for greater cooling. Fascinating. Tell me again why male necks and shoulders are bare when they are then completely {surrounded\covered} by facial and head hair? Based on cooling of the bare areas?
Any notional sexual dimorphism issue can easily be addressed by positing that remnants of hair remain as armour - thus, on males, we quite spectacularly have our necks still shielded by a matte of hair, and we do NOT lose this in old age.
Oops, looks like it isn't for cooling but for "armor" and the sexual dimorphism so "easily addressed" shows that females are not so protected and this is good? And losing head hair with old age so that it is no longer protected from the sun this too is good?
OK then, I'm going to enjoy this: would you like to explain how sexual fitness os recognised? I'm all ears.
Actually I doubt that you are willing to listen at all, for your demonstrated behavior is consistently, aggressively if not insultingly otherwise.
But for the record, and as noted previously (several times in fact), sexual mating behavior involves courtship {displays\rituals} to demonstrate {ability\availability}. These involve singing, dancing and demonstrations of creativity, this is observed in other animals all over the world, and among the other apes in the world. Each species has their own level of intricacies involved, and some of them are quite complex, some quite boring.
This is not new, or unusual, or groundbreaking information. Long courtship songs are observed in many species, and not just birds, but many mammals, sometimes male solos, sometimes duets. Dancing displays are also observed in many species, and sometimes they are prima donna displays, and sometimes they are pas de deux. There are also instances where creativity is displayed in other ways; bowerbirds for example create works of "art" nests that are decorated to attract mates.
In normal courtship {displays\rituals} the more intricate songs display creativity, which selects for increased adaptability and broader ability to survive problems, and the longer songs display increased ability to survive attacks of predators and competitors. This is not new, or unusual, or groundbreaking information.
In normal courtship {displays\rituals} the dancing displays physical fitness, endurance, agility, flexibility, fighting ability and creativity with the same results. Dancing displays also frequently include displays of signal areas that have been selected over time to show readiness for mating in the particular species in question, and very often those areas are bare. This is not new, or unusual, or groundbreaking information. (And notice, in passing, that dancing displays overall fitness to a greater degree and for more situations than running ability, and this is why dancing ability is a better indicator than running ability for overall fitness).
But, and this is important, we are not talking just normal courtship {displays\rituals}, but run-away feedback selection, where a feature or set of features are selected and developed well beyond their ability to signal fitness. Head hair grows to extreme lengths, like the tails of scissortail birds, and flows down over the shoulders and back to the waist and beyond. The longer the hair the more fit the specimen is for avoiding predators in spite of greater visibility, and the more lustrous the hair the more fit the specimen is for having the nutritional resources to grow and keep the hair in that condition. Such features are not of themselves useful in survival, they are indicators of the overall fitness of the rest of the individual for survival. Again, this is not new, or unusual, or groundbreaking information.
Humans have a number of features that do not of themselves contribute to survival fitness, but which do indicate overall fitness, and among them are extreme long head hair, and extreme body bareness. Humans also have a number of features that do not of themselves contribute to survival fitness, but which signal {ability\availability} for mating, and among them are enlarged female breasts and enlarged male penis and extreme body bareness, especially in those signal areas of the female breast and buttocks.
Perhaps the only thing new, or unusual, or groundbreaking, is to attribute these features to sexual selection in humans, because people tend to be species prude, and assume that they are consciously above such base "instincts" in their personal {self\parent\ancestor} behavior.
And it is not just that these features exist, but that the patterns of their existence are consistent with a sexual {ability\availability} display feature and a runaway feedback feature.
Now lets do the summary review again (I see no need to continue further with the above, because I expect you to fluff it off without proper consideration as you have done before, nor do I see any need to answer the rest of your post as it has already been refuted):
My added comments {{in yellow}}
RUNNING:
* cannot explain long hair on head
... but does not contradict it
{{Actually it does. All that is needed for your position is a full head of hair as exists on any of the other apes. Extreme long hair that extends so far that it covers bares skin serves no cooling or protection benefit that would not be served by normal hair\fur.}}
* cannot explain hair in high sweat armpits
... but does not contradict it
{{And it needs to explain it for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism. Not contradicting is not good enough.}}
* cannot explain hair in high sweat pubic area
... but does not contradict it
{{And it needs to explain it for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism. Not contradicting is not good enough.}}
* cannot explain hair on high sweat area of male only face
... explained through standard combat adaptaion, running model reinforced
{{Actually this is not any part of a running model, this is adding a second model to explain the deficiencies of the first, and it is inconsistent in expression in sexes and inconsistent in expression over areas needing protection, like the stomach. Occams razor says that one explanation is better than two.}}
* cannot explain greater variation of hairiness in males
... cannot explain varying height in either sex aither. Duh. Natural variation is sufficient.
{{The issue is not variation alone but the degree of variation. The degree of variation of hairiness in males would be like a variation in height of males that would be two to three times our total height while the female height varies normally. You also fail to see\address the sexual dimorphism involved.}}
* cannot explain greater average hairiness of males
... explained above, does not contradict model
{{Sorry, not explained properly above, and it needs to be fully explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism. We are talking an average hairiness of males that is 2 or 3 times the hairiness of females while at the same time these are the ones doing the marathon running after the game animals. If anything the pattern should be reversed, with females hairier than males if your model was properly applied.}}
* cannot explain virtual lack of sexiness of running stars
... but does explain the sexiness of dancers and leg/foot fetishism
{{Dancers and leg/foot fetishism explained by sexiness of dancers, lack of sexiness of running stars needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
* cannot explain why the larger and faster male is hairier than the female
... you're repeating yourself, this is twice answered above
{{You miss the distinction of this argument entirely, this is relating the size of males\females to the hairiness issue. Larger=hotter, should be barer. Again on the size issue the roles of male\female hairiness should be reversed to be consistent you’re your model.}}
* cannot explain actual sexiness of singing and dancing stars
... becuase RAZD cannot read. Rock stars are only sexy becuase of TV.
{{Total failure to address the point.}}
* cannot explain that singing and dancing stars do not look like runners
... becuase they are not directly relevant
{{Correct, because singing and dancing relate to sexiness and running doesn't. You fail to address that if runners are supposed to be sexy, then why don't sexy singing and dancing stars look like runners. Again, it needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
* cannot explain actual sexiness of naked and shaved porn stars
... does, becuase hairlessness has survival value
{{Which is why we have clothes. Again, you fail to address the issue of extreme bareness of the porn stars. Notice that this issue of shaving is not restricted just to porn stars but to general behavior in attracting mates, with females shaving legs and pits (remember those?) and males shaving faces (and chest and back for the more hirsute ones). Once more, this needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
* cannot explain that porn stars do not look like runners
... RAZD becomes possibly absurdist. They are sexy by standard running ape standards.
{{Again, you fail to address the point that if runners are supposed to be sexy, then why don't sexy naked and shaved porn stars look like runners. Once more, this needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
* cannot explain the virtual lack of any similar {hair\fur} trend in other species, even ones larger than humans that run in a hot environment, as should be predicted (or at a minimum, not be unexpected) if it is survival selection related to natural variation in {hair\fur} density.
... displays startling ignorance of the easily observed and much studied heat dissipation mechanisms in all ammalls, aquatic or terrestrial. the pattern of heavier fur toward the poles and thinner, lighter fur toward the equator is undeniable.
{{Yes there is a slight general trend in other animals (as I believe I have mentioned before) but in none of them is it taken to the extreme ... {length?} that it is in humans without other caveats being involved (such as with marine animals dealing with water friction or extreme size like elephants), that is -- there are no animals comparable in size and {habitat\econiche} that have this feature. This is what I mean by similar. Plus the variation seen is more in the length of hair (and adding sheddable hair?) rather than density, so we should expect to see the remaining hair on humans to be short rather than thin, a velvet coat would suffice. I hate to keep hammering this but it may be the only way you see it: this is an issue of consistency of the pattern observed to the proposed mechanism. If your proposal is inconsistent across a number of relevant factors while another proposal is consistent across those same relevant factors, AND there are not other factors where your position is more consistent than the other proposal then your explanation of the observed evidence is weaker than the other.}}
Now you're playing dumb.
Stop playing silly buggers.
becuase RAZD cannot read
RAZD becomes possibly absurdist
displays startling ignorance
RAZD is therfore / quote: / Absurd
Strawmen arguments and ad hominum attacks are the sign of a poor argument, repeating strawman arguments after their specific errors have been pointed out demonstrate a failure of commitment to honest discussion.
I leave you (and the others reading these posts) with two final thoughts on this issue:
(1) If bareness was driven purely by runaway sexual selection then is there anything that would show that it reached the point of being detrimental to survival, that it had been carried to far to be just an ordinary species specific feature? Have humans developed any features that would increase heat retention in spite of the increased bareness? The answer is yes, and it is in two parts:
First humans have a thick layer of subcutaneous fat that is similar to the fat layers in marine animals that also need to keep warm but have the added survival need to shed hair for speed in the water (and the whales and porpoises do not have fine hair, they have no hair on these surfaces): this layer is thicker in Inuit people of the arctic than in Nordic people between them and Africa, and they are barer than the Nordic people as well as less developed for running (shorter, thicker bodies).
Second, clothes. (the reason for this thread, right?)
(2) You completely failed to address the issue of the consistent explanations of the relevant factors that I gave by sexual selection. Let me repeat them to refresh your memory again:
RUN-AWAY SEXUAL SELECTION:
  • does explain long hair on head as a typical feature of run-away selection, just like a peacock tail
  • does explain greater reduction of hair on the torso than in high sweat armpits and pubic area as being centered on baring the female breast sexual signaling area
  • does explain greater variation of hairiness in males, because the selection is (obviously) taking place in the females: thus the more consistent level of bareness in the females, as well as the greater expression of this feature overall, versus the secondary expression in the males (where is it not being selected, and thus allows for greater average hairiness, hairiness in facial areas bare in females, and greater variation in hairiness overall in males than in females)
  • does explain virtual lack of sexiness of running stars and why the larger faster male is hairier - this trait is not related to the sexual issue that is driving the bareness feature. It may have some survival advantage, but that is secondary to the driving force behind increased bareness: sex. It is likely a result and not a cause, or at best only a minor additional cause.
  • does explain actual sexiness of singing and dancing stars (song and dance are part of the mating ritual that began the run-away feedback cycle)
  • does explain that singing and dancing stars do not look like runners (they don’t need to)
  • does explain actual sexiness of naked and shaved porn stars (they are sexy because they are bare)
  • does explain that porn stars do not look like runners (they don’t need to)
  • does explain the virtual lack of any similar {hair\fur} trend in other species, ... because it is not survival related.
Address the issue of why bareness is more consistent with sexual selection as a runaway feedback feature.
Enjoy

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

This message is a reply to:
 Message 122 by contracycle, posted 01-24-2005 11:33 AM contracycle has replied

Replies to this message:
 Message 124 by contracycle, posted 01-25-2005 9:46 AM RAZD has replied

contracycle
Inactive Member


Message 124 of 161 (180412)
01-25-2005 9:46 AM
Reply to: Message 123 by RAZD
01-25-2005 1:27 AM


Re: And the winner is ... (can I have the envelope please ...)?
quote:
You are conflating two different arguments. Why should sexual selection explain a survival feature? Do male peacock tail feathers explain the remarkable ability of peacocks to fly or walk or crow?
Because otherwise the organism has no basis for judging the sexiness of a potential mate. As I have already pointed out, "sexual selection" as a phrase is entirely useless for any productive discussion; the ONLY thing it can meaningfully address on its own is runaway counterproductive processes. This is why it is totally inadequate as an explanation for human hair loss, as hair loss appears fundamental to our aboriginal mode of operation.
quote:
This is as irrelevant as the baleen example to my position.
Baleen was only offered as a falsification of your claim that the ONLY influence ever observed on hair is non-productiove sexual selection. The Baleen example demonstrates clearly that hair can and has been the subject of specific fitness developement.
quote:
For the record I have noted before it takes the human tracking ability and the conscious behavior to not exhaust oneself in the running, and that is sufficient to differentiate human behavior from other animals in that particular behavior.
It is not I'm afraid. First of all, many animals can track - that is very far from a uniquely human ability. Secondly, all running animals pace themselves - otherwise they would be routinely running themselves to death as soon as they were chased by a rpedator, and that simply does not happen. It's trivial to observe that wolves, for example, have a loping gate for covering distances and a sprint gate for the chase. Horses have many more gaits than that. This is a non-problem.
quote:
Whether that behavior can then be the basis for bareness rather than just the usual long limbs and good lungs of all other running animals has not been shown.
Only if you ignore bipedalism. Now the argument I am working from takes bipedalism to be very important, becuase by being bipedal we do not lose energy invested in locomation as 4-legfged animals do when the front half of their bodies come crashing down with every step. We are inherently unstable when running, unlike like 4-leggeds, becuase we are permanently off balance and running to keep up. And this means that our running is more efficient than that of quadrupeds, and that other adaptations, such as loss of hair EXCEPT on the top of the head (and some other trivial bits) is directly related to our bipedalism.
quote:
Run the experiment as I outlined and see what the results are. Until then, you don't have any basis for your claim, or your insults, or your false strawmen arguments and ridiculous non-sequiturs, or your unwillingness to look at other information. Especially when you repeat the strawmen arguments when they have been shown to be false representations. Sorry, but I expected better.
Thats just sour grapes, RAZD.
[quote] This is new: your model of hair loss for greater cooling now predicts that human head hair is the longest hair in the ape kingdom, to the point where it completely covers many areas that are supposedly bared for greater cooling. Fascinating. Tell me again why male necks and shoulders are bare when they are then completely {surrounded\covered} by facial and head hair? Based on cooling of the bare areas?[/qupte]
And yet again your argument depends on systematic dishonesty. I did not say that my model predicted LONG hair; I said that my model predicted the RETENTION OF HEAD HAIR. This is a dishonest manipulation of my argument, isn't it RAZD? You have done it repeatedly, please desist.
quote:
Oops, looks like it isn't for cooling but for "armor" and the sexual dimorphism so "easily addressed" shows that females are not so protected and this is good? And losing head hair with old age so that it is no longer protected from the sun this too is good?
Yes. I mean please, your argument sounds like that of a 9-year old: if I say that running is a basic mode of production you choose to interpret that as the claim that "there are and can be no other influences". Thats just childish, RAZD, please advance an adult argument. It is frankly stupid to pretend that only one influence is ever operational. Whatever physical form finally emerges will be a synthersis of ALL envrionmental pressures, not only one.
In apes and many other animals, hair serves as armour. In a running ape, most of that armour can be lost, but its not cost efficient to lose the neck-armour of your primary combatants - because that is the place most predators know to attack! If you look at military history you will observe that mobility and combat effectiveness are inherently countervailing trends. Similarly, the loss of head hair in old men is no biggie if they are no longer fit enough to handle the long chase at all. Your argument descends to pettiness.
quote:
Actually I doubt that you are willing to listen at all, for your demonstrated behavior is consistently, aggressively if not insultingly otherwise.
Thats what you get when you twist your opponents argument to discredit it. If you will not debate honestly, you are not worthy of honest debate.
quote:
But, and this is important, we are not talking just normal courtship {displays\rituals}, but run-away feedback selection, where a feature or set of features are selected and developed well beyond their ability to signal fitness.
Recapaitulation of mating basics for kindergarten ommitted. Here is the question you persistently refuse to engage with: ARE we looking at runaway selction, or are we looking at environmental adaptation? If so, what is the basis for that claim, and for ruling out the appearence of bareness as related to fitness? That is purely an assumption on your part which you have so far only been able to defend by analogy to other animals. By your logic, we would be compelled to conlude that the fine hair in cetaceans did NOT evolve as a response to the environment in which they find themselves, even progressively over millions of years. No, apparently its purely an accident that cetacean hair contributes to their swimming efficiency; according to your argument, the illogical runaway sexually selected feedback that produced this fine hair could just as easily have produced a thick mass of fur that would have impeded their swimming.
So how is it there is not a single aqautic mammal with long hair, and that all aquatic mammals are as streamlined as their body form can make? According to your argument, thats not even a meaningful question.
quote:
Head hair grows to extreme lengths, like the tails of scissortail birds, and flows down over the shoulders and back to the waist and beyond. The longer the hair the more fit the specimen is for avoiding predators in spite of greater visibility, and the more lustrous the hair the more fit the specimen is for having the nutritional resources to grow and keep the hair in that condition. Such features are not of themselves useful in survival, they are indicators of the overall fitness of the rest of the individual for survival. Again, this is not new, or unusual, or groundbreaking information.
Sure. Unfortunately, none of it supports your argument. The fact that it is reasonable to interpret long head hair as sexually selected does not in any sense imply that the elmination of body hair was selected by the same mechanism. Is it your argument that the perfectly serviceable short feathers on peacocks are also sexually selected for smallness? I have never denied the PRESENCE of sexual selection, nor its potential counter-poroductive outcome. But what you have NOT shown is why it should be thought that hairlessness in humans is related to this process.
quote:
umans have a number of features that do not of themselves contribute to survival fitness, but which do indicate overall fitness, and among them are extreme long head hair, and extreme body bareness.
Nonsense - you are arguing your conclusion. It is NOT shown that body bareness is non-contributing to our fitness. I have cogently argued that it DOES contribute to our fitness, and that this is in line with all other mammals and their appraoch to temperature regulation.
quote:
And it is not just that these features exist, but that the patterns of their existence are consistent with a sexual {ability\availability} display feature and a runaway feedback feature.
Except that when I point out that human hairlessness does NOT look like a runaway feedback process precisely because it is constrained by operational needs for head-top and genital hair, you dismiss this out of hand. There is no basis whatsoever for thinking human hairlessness is unrelated to our fitness, and many reasons for thinking it is directly related.
quote:
answer the rest of your post as it has already been refuted):
Diddums. Would Baby like a rattle to throw out of his cot?
quote:
{{Actually it does. All that is needed for your position is a full head of hair as exists on any of the other apes. Extreme long hair that extends so far that it covers bares skin serves no cooling or protection benefit that would not be served by normal hair\fur.}}
Once again you twist my argument. I never claimed that LONG hair on the human head is required by my model. The fact that this long hair MAY cause certain problems is easily dealt with by your own runaway sexual selection model. Please apply your own arguments concistently, no opportunistically.
quote:
{{And it needs to explain it for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism. Not contradicting is not good enough.}}
Nonsense as I have already explained multiple times - there may be another need othogonal to heat dissipation that triggers this pehnomenon. I have proposed scent-trapping; this is reinforced by recent research that mosquitos are repelled by certain chemicals we excrete through the skin. Thus there may be a need to have scent-traps in certain areas even if hairlessness is an optimum solution. And thus a compromise is arrived at; this is not rocket science, RAZD, and comprehensively demonstrates theat your objection is not a falsifier.
quote:
{{Actually this is not any part of a running model, this is adding a second model to explain the deficiencies of the first, and it is inconsistent in expression in sexes and inconsistent in expression over areas needing protection, like the stomach. Occams razor says that one explanation is better than two.}}
Ha ha ha. I see, so now organisms living in a chaotic world are expected to be subject to only ONE evolutionary influence at a time? Can you cite any other examples? Why don't all birds have an albatross's singularly refined wing? Might it perhaps be because they have OTHER NEEDS that mean that a different wing is a better choice? Evolution does not occur in a wind tunnel hermetically sealed from other influences, RAZD.
As to why the neck is protected, it is quite simply becuase the neck is an efficient point to attack. Almost all chase and pounce predators attack the neck by preference, aquatic aniumals excepted.
quote:
{{Sorry, not explained properly above, and it needs to be fully explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism. We are talking an average hairiness of males that is 2 or 3 times the hairiness of females while at the same time these are the ones doing the marathon running after the game animals. If anything the pattern should be reversed, with females hairier than males if your model was properly applied.}}
Actually thats nonsense. As we recently discussed in relation to light and dark skin tones in men and women, in a thread raised by Brennakimi, it is plausible to see a selection for darkness in men by women, and a commensurate selection for lightness in women by men, would have the effect of two diagonal vectors being synthesised into a singular vector between the two, while retaining that dimorphism in expressed phenotypes.
Again what you fail to address is that fitness is negotiated by feedback from the world, not laid down by law from above and conformed to. The trade off between armour and speed is a fundamental physical limitaion that applies to all physical objects as an artifact of physics.
AND THEN, for whatever elements you still find unexplained, I can resort to your own sexual selection to rationalise the outliers. Peacocks do not have tails FOR THE PURPOSES of being sexy; they have tails as a result of being birds, and that being part of the package. Any subsequent sex-sexlected influence is seocndary to the fitness influences that casued tail features to appear in the first place. Similarly, I can argue that hairlessness is explained by fitness almost entirely, and any remaining weirdness can be rationalised.
quote:
{{Dancers and leg/foot fetishism explained by sexiness of dancers, lack of sexiness of running stars needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
And it has been explained - Beyonce appears daily on TV before pubescent boys every day, how often does anyone view running stars? Again, this is a totally spurious objection and can be dismissed as silly. I remind you again that sexinees of dancers can also be explained by the running model, thius this is no way a falsification either.
quote:
{{You miss the distinction of this argument entirely, this is relating the size of males\females to the hairiness issue. Larger=hotter, should be barer. Again on the size issue the roles of male\female hairiness should be reversed to be consistent you’re your model.}}
Except thats inherently nonsense, assuming that evolution is occurring in an environemnt that only ever applies one influence at a time, nor that multiple influences might require compromise designs. Yes, its a trade-off - so what? This is not a falsification either.
Ha ha ha - pot/kettle
quote:
You fail to address that if runners are supposed to be sexy, then why don't sexy singing and dancing stars look like runners. Again, it needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
Actually this raise an interesting falsification to your claim: male dancers often look terrible. This is because they do so many lifts and jumps that they develop these massive thighs and calves and have totally weedy upper bodies, contradicting the male V-shape quite dramatically.
But by all means expand on what precisely you feel the differences in the body form between runners and dancers are. your initial claim was that this was represented by GROUPIES, but I have already dealt with that claim. Many many dancers are very muscular people - please expand.
quote:
{{Which is why we have clothes. Again, you fail to address the issue of extreme bareness of the porn stars.
I find it absurd that you think this is a serious point; I assumed it was throw-away you reached for while on the ropes. Even if I take this silly claim at face failure, it simply does not support your claim the way you appear to think it should; my argument shows that there might be a reason for selcting hairlessness, your argument is only that it is entirely accidental.
quote:
Notice that this issue of shaving is not restricted just to porn stars but to general behavior in attracting mates, with females shaving legs and pits (remember those?) and males shaving faces (and chest and back for the more hirsute ones). Once more, this needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
LOL does it now. Becuase shaving is such a new phenomnon I'm not sure that it has anything meaningful to say about our evolutionary history. In feudal Ireland, British men-at-arms were instructed to shave "if they would be taken for Englishmen", because it was common for the Irish to wear very large mustaches. Not all shave their armpits anyway - to the best of my knowledge that is essentially a Western affectation, and I am not aware on any research on its commonality in other societies.
quote:
{{Again, you fail to address the point that if runners are supposed to be sexy, then why don't sexy naked and shaved porn stars look like runners. Once more, this needs to be explained for the mechanism to have credibility. This is an issue of consistency of the pattern observed to the proposed mechanism.}}
What you fail to ackonowledge, RAZD, is that we ALL look like runners. Porn selects for beauty, more or less, which according to my arguments MEANS "looking like runners". So by and large this means: long legged, slim, symmetrical. This does not challenge my point in any way.
quote:
* cannot explain the virtual lack of any similar {hair\fur} trend in other species, even ones larger than humans that run in a hot environment, as should be predicted (or at a minimum, not be unexpected) if it is survival selection related to natural variation in {hair\fur} density.
Except, so what? If we have now-dead relatives in the Naenderthals, and in other pre-human primates, then we have a clear niche that is being consistently exploited by animals with the appropriate bodyform. The fact that WE happen to occupy this niche alone is no way a sound argument. There are very few mammals in the sea - do you take them to be absurd aberrations?
Once again, your objection to not seeing similar trends in bigger running animals is facetious; I have already shown that many of the really big svannah animals already are hairless or nearly so; many of the others, such as camels, have other countervailing conditions to cnotend with, such as the extreme cold of desert nights. Ironically for someone claiming to advance a naturalist hypoethis, you are failing to account for the complexity of natural conditions. If you have a specific case to present, do so.
quote:
{{Yes there is a slight general trend in other animals (as I believe I have mentioned before) but in none of them is it taken to the extreme ... {length?} that it is in humans without other caveats being involved (such as with marine animals dealing with water friction or extreme size like elephants)
But my argument is preciselty that it IS occurring becuase of those other influences anaologous to water friction; that it is occurring as a fitness-maximising feature.
quote:
that is -- there are no animals comparable in size and {habitat\econiche} that have this feature.
But considering that for examples we find strange pockets of marsupials, and that the duck-billed platypus appears to be such a werid conglomeration of random features (some of which without precedent, such as the poison spurs) that this argument from incredulity is simply weak.
quote:
This is what I mean by similar. Plus the variation seen is more in the length of hair (and adding sheddable hair?) rather than density, so we should expect to see the remaining hair on humans to be short rather than thin, a velvet coat would suffice. I hate to keep hammering this but it may be the only way you see it: this is an issue of consistency of the pattern observed to the proposed mechanism.
Yes exactly so, and depite your various attempts you have failed to show any failure in this consistency. Animals that shed their coats inhabit regions with major seasonal temperature fluctuations; the African savannah as a rule does not experience these to any significant degree. Equally, if a velvet coat "might" suffice, that does not imply that it would necessarily have been selected - ANY solution that is good enough will do. Further, I don't think a velvet coat would suffice on the basis, I have read, that we sweat easily copiously by comparison with other animals.
quote:
If your proposal is inconsistent across a number of relevant factors while another proposal is consistent across those same relevant factors, AND there are not other factors where your position is more consistent than the other proposal then your explanation of the observed evidence is weaker than the other.}}
Exactly so. That is preciesly why inexplicable random sexual selection out of the blue is substantially inferior to the running ape hypothesis.
quote:
Strawmen arguments and ad hominum attacks are the sign of a poor argument, repeating strawman arguments after their specific errors have been pointed out demonstrate a failure of commitment to honest discussion.
Yes thats true, RAZD, and yet you have concistently perpetrated all of them. This very post of yours is in large part re-raising straw men I have already dealt with.
quote:
First humans have a thick layer of subcutaneous fat that is similar to the fat layers in marine animals that also need to keep warm but have the added survival need to shed hair for speed in the water (and the whales and porpoises do not have fine hair, they have no hair on these surfaces): this layer is thicker in Inuit people of the arctic than in Nordic people between them and Africa, and they are barer than the Nordic people as well as less developed for running (shorter, thicker bodies).
I see. So maybe that arose due to counterproductive runaway sexual selection? See how easy the non-answwer is to use?
Even if it is true that, after hairlessness became a fundamental fitness feature (like tails in birds), sexual selection ran away with it to the point that it became counter-productive, THIS DOES NOT SUPPORT THE CLAIM THAT IT HAS OCCURRED ONLY DUE TO SEXUAL SELECTION.
quote:
(2) You completely failed to address the issue of the consistent explanations of the relevant factors that I gave by sexual selection. Let me repeat them to refresh your memory again:
I ran out of time, get a grip.
quote:
# does explain long hair on head as a typical feature of run-away selection, just like a peacock tail
Agreed. Except, my explanation gives us a basis for seeing it on the head in the first place. Your argument requires two seperate and contradictory selection trends: first selecting for hairlessnes,, and then selcting for long hair length. mny explanation accord much more closely with the observed facts and requirtes fewer assumptions.
quote:
# does explain greater reduction of hair on the torso than in high sweat armpits and pubic area as being centered on baring the female breast sexual signaling area
Despite the fact that it occurs over the whole body, thus uindermining the claim that it is intended to reveal the breasts. This is further undermineind by the continuation of hair on the genitals.
quote:
# does explain greater variation of hairiness in males, because the selection is (obviously) taking place in the females: thus the more consistent level of bareness in the females, as well as the greater expression of this feature overall, versus the secondary expression in the males (where is it not being selected, and thus allows for greater average hairiness, hairiness in facial areas bare in females, and greater variation in hairiness overall in males than in females)
Oh its "obvious" its occurring in the females, is it? Thats blatant thumb-sucking, RAZD, its only "obvious" if you assume your conclusion.
quote:
# does explain virtual lack of sexiness of running stars and why the larger faster male is hairier - this trait is not related to the sexual issue that is driving the bareness feature.
This notional lack of sexiness in running stars has not in any way, shape or form been demonstrated, becuase of the differing degrees of social value attributed to their professions, which is purely temporal phenomenon.
quote:
# does explain actual sexiness of singing and dancing stars (song and dance are part of the mating ritual that began the run-away feedback cycle)
Not at all - becuase the very argument to dancing, which is a pedal motion, may also be a flautning or demonstration of running fitness.
quote:
# does explain that singing and dancing stars do not look like runners (they don’t need to)
Except you will recall the advent of TV killed off the ugly singer who could carry a career. Now you need be a good singer, and also be slim and fit like a runner.
quote:
# does explain actual sexiness of naked and shaved porn stars (they are sexy because they are bare)
... which requires assuming the conclusion
quote:
# does explain that porn stars do not look like runners (they don’t need to)
... except they do anyway
quote:
# does explain the virtual lack of any similar {hair\fur} trend in other species, ... because it is not survival related.
... except that temperature regulation techniques are fundamental to all mammals, and many mamalls exhibit hair that conforms to their local environments, even varying in thickness seasonally to react to external conditions.
In all respscts your argument is hogwash. Here are some exaples of features that humans exhibit whioch you need to explain, then:
quote:
Anatomical Features that Help Humans Run
Here are anatomical characteristics that are unique to humans and that play a role in helping people run, according to the study:
Skull features that help prevent overheating during running. As sweat evaporates from the scalp, forehead and face, the evaporation cools blood draining from the head. Veins carrying that cooled blood pass near the carotid arteries, thus helping cool blood flowing through the carotids to the brain.
A more balanced head with a flatter face, smaller teeth and short snout, compared with australopithecines. That "shifts the center of mass back so it's easier to balance your head when you are bobbing up and down running," Bramble says.
A ligament that runs from the back of the skull and neck down to the thoracic vertebrae, and acts as a shock absorber and helps the arms and shoulders counterbalance the head during running.
Unlike apes and australopithecines, the shoulders in early humans were "decoupled" from the head and neck, allowing the body to rotate while the head aims forward during running.
The tall human body - with a narrow trunk, waist and pelvis - creates more skin surface for our size, permitting greater cooling during running. It also lets the upper and lower body move independently, "which allows you to use your upper body to counteract the twisting forces from your swinging legs," Bramble says.
Shorter forearms in humans make it easier for the upper body to counterbalance the lower body during running. They also reduce the amount of muscle power needed to keep the arms flexed when running.
Human vertebrae and disks are larger in diameter relative to body mass than are those in apes or australopithecines. "This is related to shock absorption," says Bramble. "It allows the back to take bigger loads when human runners hit the ground."
The connection between the pelvis and spine is stronger and larger relative to body size in humans than in their ancestors, providing more stability and shock absorption during running.
Human buttocks "are huge," says Bramble. "Have you ever looked at an ape? They have no buns." He says human buttocks "are muscles critical for stabilization in running" because they connect the femur - the large bone in each upper leg - to the trunk. Because people lean forward at the hip during running, the buttocks "keep you from pitching over on your nose each time a foot hits the ground."
Long legs, which chimps and australopithecines lack, let humans to take huge strides when running, Bramble says. So do ligaments and tendons - including the long Achilles tendon - which act like springs that store and release mechanical energy during running. The tendons and ligaments also mean human lower legs that are less muscular and lighter, requiring less energy to move them during running.
Larger surface areas in the hip, knee and ankle joints, for improved shock absorption during running by spreading out the forces.
The arrangement of bones in the human foot creates a stable or stiff arch that makes the whole foot more rigid, so the human runner can push off the ground more efficiently and utilize ligaments on the bottom of the feet as springs.
Humans also evolved with an enlarged heel bone for better shock absorption, as well as shorter toes and a big toe that is fully drawn in toward the other toes for better pushing off during running
Article here: http://www.scienceinafrica.co.za/2005/january/running.htm
Less detailed article containing some counter-arguments for your perusal here:
Unlike apes, humans were born to run, study says / Finding could help date human evolution -- but other scientists say theory is bunk
Both refer to the same research.

This message is a reply to:
 Message 123 by RAZD, posted 01-25-2005 1:27 AM RAZD has replied

Replies to this message:
 Message 125 by pink sasquatch, posted 01-25-2005 12:45 PM contracycle has replied
 Message 126 by MangyTiger, posted 01-25-2005 3:19 PM contracycle has not replied
 Message 128 by RAZD, posted 01-25-2005 10:15 PM contracycle has replied

pink sasquatch
Member (Idle past 6271 days)
Posts: 1567
Joined: 06-10-2004


Message 125 of 161 (180446)
01-25-2005 12:45 PM
Reply to: Message 124 by contracycle
01-25-2005 9:46 AM


Re: And the winner is ... RAZD?
In all respscts your argument is hogwash. Here are some exaples of features that humans exhibit whioch you need to explain, then:
Your list of a dozen or so features don't include hair, or lack thereof. Neither site mentioned hair that I saw.
It seems to me RAZD is arguing sexual selection of hairlessness, so why exactly does he need to explain those dozen mostly skeletal features?
Kudos to your nicely referenced strawman.

This message is a reply to:
 Message 124 by contracycle, posted 01-25-2005 9:46 AM contracycle has replied

Replies to this message:
 Message 131 by contracycle, posted 01-26-2005 4:56 AM pink sasquatch has replied

MangyTiger
Member (Idle past 6602 days)
Posts: 989
From: Leicester, UK
Joined: 07-30-2004


Message 126 of 161 (180472)
01-25-2005 3:19 PM
Reply to: Message 124 by contracycle
01-25-2005 9:46 AM


Re: And the winner is ... (can I have the envelope please ...)?
Except you will recall the advent of TV killed off the ugly singer who could carry a career. Now you need be a good singer, and also be slim and fit like a runner.
Yeah those pople like Pavarotti, Barry White and Mama Cass are never going to make it...

Confused ? You will be...

This message is a reply to:
 Message 124 by contracycle, posted 01-25-2005 9:46 AM contracycle has not replied

Replies to this message:
 Message 127 by RAZD, posted 01-25-2005 6:18 PM MangyTiger has not replied

RAZD
Member (Idle past 1654 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 127 of 161 (180570)
01-25-2005 6:18 PM
Reply to: Message 126 by MangyTiger
01-25-2005 3:19 PM


Re: And the winner is ... (can I have the envelope please ...)?
Not to mention Qheen Latifa who was HOT in "chicago" and Stevie Nicks and ...
but when you argue from a closed mind you will not see the evidence that surrounds you.

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

This message is a reply to:
 Message 126 by MangyTiger, posted 01-25-2005 3:19 PM MangyTiger has not replied

RAZD
Member (Idle past 1654 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 128 of 161 (180624)
01-25-2005 10:15 PM
Reply to: Message 124 by contracycle
01-25-2005 9:46 AM


No progress yet.
contracycle writes:
Baleen was only offered as a falsification of your claim that the ONLY influence ever observed on hair is non-productiove sexual selection.
You just can't get this out of your head can you? (OR get it right). Tell you what: find that post where I made that specific claim.
Then when you can't do that, find the posts where I explained the difference between this claim and what I really said. List each one, if you don't know the difference, with complete verbatum quotes.
This is what a strawman argument is: a false representation of the opposing view in an easily refuted fake form. This is your argument here, this is most of your argument.
I await your effort.
The rest of your post? heh. Still doesn't answer why run-away sexual selection provides more answers and more self consistent answer to the list of factors that I gave.
That fact alone should give you a clue.
Yes thats true, RAZD, and yet you have concistently perpetrated all of them. This very post of yours is in large part re-raising straw men I have already dealt with.
Perhaps you really don't know what the strawman argument is. See
Forbidden
I did not say that my model predicted LONG hair; I said that my model predicted the RETENTION OF HEAD HAIR.
Actually, I have asked you repeatedly for the explanation of long hair on the heads of humans, and this is the only answer you have provided. If that is not your answer for long hair, then you still have not answered that problem, which means that you are equivocating. "Retention of head hair" only means it would be like the hair on other apes. It isn't. It remarkably isn't. It fantastically isn't. Again your model falls short of explaining the actually observed features.
This is consistently your problem: in spite of all the misrepresentations of my arguments and all the ad hominums, your model does not consistently explain the observed features and behavior of humans, and sexual selection does.
{{If anything the pattern should be reversed, with females hairier than males if your model was properly applied. }}
Actually thats nonsense. As we recently discussed in relation to light and dark skin tones in men and women, in a thread raised by Brennakimi, it is plausible to see a selection for darkness in men by women, and a commensurate selection for lightness in women by men, would have the effect of two diagonal vectors being synthesised into a singular vector between the two, while retaining that dimorphism in expressed phenotypes.
And now explain how this results in the hairier males that are doing the running that the hairlessness is being selected for while resulting in barer females? I could try to state this for you but you seem to go off the handle when I do: perhaps you could elucidate with clarity just exactly how this occurs?
{{ lack of sexiness of running stars needs to be explained for the mechanism to have credibility. }}
this is a totally spurious objection and can be dismissed as silly
Because you have no other valid way to dismiss it? Seems to be your main argument.
{{Again, you fail to address the issue of extreme bareness of the porn stars. }}
I find it absurd that you think this is a serious point; I assumed it was throw-away you reached for while on the ropes. Even if I take this silly claim at face failure, it simply does not support your claim the way you appear to think it should; my argument shows that there might be a reason for selcting hairlessness, your argument is only that it is entirely accidental.
What you fail to understand (apart from my argument entirely, as it is here - again - totally misrepresented) is that I have never been on the ropes, and that I am very serious about this issue. I notice again that you dismiss the argument instead of address it.
Lets look at that final list now and see what you have learned:
Comments again {{in yellow}} below
I ran out of time, get a grip.
{{I could, but I won't stoop to your level, in spite of the many such opportunities. Perhaps if you spent less time on gratuitous insults you would have more time to address the issues.}}
quote:
# does explain long hair on head as a typical feature of run-away selection, just like a peacock tail
Agreed. Except, my explanation gives us a basis for seeing it on the head in the first place. Your argument requires two seperate and contradictory selection trends: first selecting for hairlessnes,, and then selcting for long hair length. mny explanation accord much more closely with the observed facts and requirtes fewer assumptions.
{{False on several counts. One is that hair was already on the head, so existence there does not need to be explained. What needs to be explained is why it is the longest hair in the ape family by several factors much longer comparatively than the tail feathers of the scissortail bird compared to other birds of that size and weight. This is not explained by your running model or your (newly added) armor model. This is adequately explained by runaway sexual selection just as the tail feathers are. Further, the simultaneous selection for bareness in other areas known to be associated with signaling sexual {ability\availability} is not a contradiction (or your silly strawman version) but exactly the same mechanism in operation at the same time for the same purpose: {displaying\recognizing} sexual {ability\availability}. Rather than two mechanisms (your version, oh, and your model is (now) two entirely different mechanisms isn't it?) there is one. Agreeing that long hair shows runaway sexual selection and then adamantly arguing that no other features show this aspect of selection is disingenuous at best.}}
quote:
# does explain greater reduction of hair on the torso than in high sweat armpits and pubic area as being centered on baring the female breast sexual signaling area
Despite the fact that it occurs over the whole body, thus uindermining the claim that it is intended to reveal the breasts. This is further undermineind by the continuation of hair on the genitals.
{{Occurs over the rest of the body in decreasing degree. The female breast and buttocks remain the barest skin areas in humans, and these areas are documented sexual signal areas in other apes (rather than genitals). My argument has consistently been that it is extreme selection for bareness in sexual signal areas.}}
quote:
# does explain greater variation of hairiness in males, because the selection is (obviously) taking place in the females: thus the more consistent level of bareness in the females, as well as the greater expression of this feature overall, versus the secondary expression in the males (where is it not being selected, and thus allows for greater average hairiness, hairiness in facial areas bare in females, and greater variation in hairiness overall in males than in females)
Oh its "obvious" its occurring in the females, is it? Thats blatant thumb-sucking, RAZD, its only "obvious" if you assume your conclusion.
{{And again you fail to address the issue and rely on dismissal. Yes it is obvious. If you have a feature that is more extremely expressed in sex (A) than in sex (B), that is more homogeneously (less variation on each individual) expressed in sex (A) than in sex (B), that is more consistently (less variation between individuals) expressed in sex (A) than in sex (B), then it is obvious that the feature is being selected in sex (A) rather than in sex (B). Peacock tails are obviously selected in the male species. Bareness is obviously selected in the female species. Conversely, if the other sex displays the feature with wide variation between individuals, wider variation on each individual and to a lesser degree overall, then it is obviously a secondary expression of the selection. One would expect this other sex to range from nearly the degree expressed in the primary selection sex to a virtual non-expression of the feature. That is just what is observed in males, in fact the hairiest males have almost the same degree of hair as the chimpanzees do.}}
quote:
# does explain virtual lack of sexiness of running stars and why the larger faster male is hairier - this trait is not related to the sexual issue that is driving the bareness feature.
This notional lack of sexiness in running stars has not in any way, shape or form been demonstrated, becuase of the differing degrees of social value attributed to their professions, which is purely temporal phenomenon.
{{In other words, you could not find examples, eh? Orthogonal traits are like that.}}
quote:
# does explain actual sexiness of singing and dancing stars (song and dance are part of the mating ritual that began the run-away feedback cycle)
Not at all - becuase the very argument to dancing, which is a pedal motion, may also be a flautning or demonstration of running fitness.
{{As noted previously, dancing exhibits more fitness in more areas to a greater degree than just running (see previous post for the "rundown" on it). As just one example, running does not display creativity, while dancing does. Dancing displays fitness for (A,B,C and D) while running displays fitness for (A). This is an inductive logical error to think that running is more descriptive of fitness than dancing.}}
quote:
# does explain that singing and dancing stars do not look like runners (they don’t need to)
Except you will recall the advent of TV killed off the ugly singer who could carry a career. Now you need be a good singer, and also be slim and fit like a runner.
{{Yeah, who was that guy that won the first "American Idol" competition? And Stevie Nicks, Queen Latifa, Mama Cass and etcetera are just second class talent that couldn't pack an auditorium}}
quote:
# does explain actual sexiness of naked and shaved porn stars (they are sexy because they are bare)
... which requires assuming the conclusion
{{False. Evidence that supports the conclusion that it is bareness that is sexy.}}
quote:
# does explain that porn stars do not look like runners (they don’t need to)
... except they do anyway
{{Actually the more attractive ones look better than runners because they appear adequately fed, healthy and creative: strong reasons to be good mate material.}}
quote:
# does explain the virtual lack of any similar {hair\fur} trend in other species, ... because it is not survival related.
... except that temperature regulation techniques are fundamental to all mammals, and many mamalls exhibit hair that conforms to their local environments, even varying in thickness seasonally to react to external conditions.
{{And yet seasonal variation is curiously lacking in humans, specific reference is made again to the Inuit people, that could benefit most from a little variation and where cooling is not necessary anymore.}}
In all respscts your argument is hogwash. Here are some exaples of features that humans exhibit whioch you need to explain, then:
{{Why? Because you miss the point that the argument is about selection of bareness in humans and not about baleen in whales or thick coats of fur with closed air cells in cariboo?}}
Nope, still same old inconsistent answers. Still much less of an argument for running as the prime mover of bareness than for sexual selection.
I listed factors that tied bareness to sexual selection for {ability\availability} and showed that in each case the explanation for those factors was (A) consistent with sexual selection and (B) inconsistent with running selection. You have not listed any more factors that relate to bareness.
Enjoy.
ps - how do you explain art (all forms) as a result of evolution?

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

This message is a reply to:
 Message 124 by contracycle, posted 01-25-2005 9:46 AM contracycle has replied

Replies to this message:
 Message 132 by contracycle, posted 01-26-2005 6:15 AM RAZD has replied

arachnophilia
Member (Idle past 1592 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 129 of 161 (180679)
01-26-2005 1:36 AM
Reply to: Message 119 by lfen
01-24-2005 2:49 AM


drawrings.
My experience of drawing and the way I was taught one had to look analytically and render lines, values, shapes.
well, yes, of course. i'm sort of unusual, and i'm well aware that i am the exception to a good many rules in artistic areas. my drawing process relates entirely to light and shadow. on good nights, i totally disconnect from any cognitive process (ie: "this is a hand! and that's a finger!") and just focus on what things look like.
since attraction and sexuality are very low in the hierarchy of conciousness, i find that just a little bit helps to hold my attention. i tend to draw better when i find things asthetically pleasing. you'll find similar things in photographers (also a member of that group) in that they attempt to make even ugly things pretty.
It used to amaze me that when I would step back that there would be a drawing there and I would wonder who had done it for all I had done was try to render relationships onto the paper.
i don't really think i draw. because when i do it well, i've shut off my concious processes, and done it entirely mechanically and subconciously. when i think about it, or can't focus into the proper mindset, i can't draw at all.
Drawing seemed to me a very abstract thing and if the model was a woman I found very attractive it was hard for me to let go of her totality the gestalt of which was "beautiful desirable woman" and instead look to the particular abstract shape of the shadow, or the shape of the highlight on her breast, or cheek, or the apparent angle of her shoulder to her neck and thus lose my awareness of her body, momentarily, as a total and instead analyze what I was visually seeing.
i taught myself years back to see a totally different way. so i can (sometimes) shut one way of seeing off completely, and usually totally at will. i say sometimes because about half the time i just plain suck. but it never seems to have much to do with attraction, since we used the same models for long stretches of time.
Perhaps you draw differently, maybe they are teaching drawing differently?
the first option. my experience in art classes is that i've ignored what most of the teachers have taught, and drawn fundamentally differently than most of the students. for starters, i'm about three times as fast. i had one teacher that did teach differently and i blame it on her even though i don't follow her method exactly.

This message is a reply to:
 Message 119 by lfen, posted 01-24-2005 2:49 AM lfen has replied

Replies to this message:
 Message 130 by lfen, posted 01-26-2005 1:54 AM arachnophilia has not replied

lfen
Member (Idle past 4926 days)
Posts: 2189
From: Oregon
Joined: 06-24-2004


Message 130 of 161 (180682)
01-26-2005 1:54 AM
Reply to: Message 129 by arachnophilia
01-26-2005 1:36 AM


Re: drawrings.
Arach,
Okay, I think I understand. Thanks for explaining. I'll drop this thread within a thread and let them get back to arguing body and facial hair. Hah!
lfen

This message is a reply to:
 Message 129 by arachnophilia, posted 01-26-2005 1:36 AM arachnophilia has not replied

contracycle
Inactive Member


Message 131 of 161 (180708)
01-26-2005 4:56 AM
Reply to: Message 125 by pink sasquatch
01-25-2005 12:45 PM


Re: And the winner is ... RAZD?
quote:
Your list of a dozen or so features don't include hair, or lack thereof. Neither site mentioned hair that I saw. It seems to me RAZD is arguing sexual selection of hairlessness, so why exactly does he need to explain those dozen mostly skeletal features? Kudos to your nicely referenced strawman.
MY strawman? Of all the arrogant bullshit...
Its very simple Sasquatch. As RAZD has been at pains to point out, what matters is consistency with all observed phenomenon. RAZD advances this argument - human hairlessness is INEXPLICABLE from efficiency or fitness concersn, therefore it MUSTN BE due to runaway sexual selection.
My argument is that there IS an hypothesis in which the adapatation is functional, and that is the running ape model. There is no need to default to sexual selection FOR LACK OF ANY OTHER HYPOTHESIS. And in order to challenge that claim RAZD has been arguing that the running ape model is ridiculous in toto.
Therefore it is entirely accurate to demonstrate the other evidence that corroborates the running ape model and which contributes to the model as a whole. RAZD keeps saying that hairlessness is "odd" and needs to be accounted for, but completely fails to account for the many adaptations we clearly have to our most basic functional mode - bipedalism, and out amazing capacity for covering disdtances at speed.

This message is a reply to:
 Message 125 by pink sasquatch, posted 01-25-2005 12:45 PM pink sasquatch has replied

Replies to this message:
 Message 133 by pink sasquatch, posted 01-26-2005 12:47 PM contracycle has replied

contracycle
Inactive Member


Message 132 of 161 (180716)
01-26-2005 6:15 AM
Reply to: Message 128 by RAZD
01-25-2005 10:15 PM


Re: No progress yet.
quote:
Then when you can't do that, find the posts where I explained the difference between this claim and what I really said. List each one, if you don't know the difference, with complete verbatum quotes.
This is what a strawman argument is: a false representation of the opposing view in an easily refuted fake form. This is your argument here, this is most of your argument.
Well RAZD, if I misunderstood your argument and responded innaproprioately, that is still no excuse for misrepresenting WHY I produced Baleen as a counter-point, and trying to make it say things I never intended it tos say. Mistakes happen; adults realise this.
quote:
The rest of your post? heh. Still doesn't answer why run-away sexual selection provides more answers and more self consistent answer to the list of factors that I gave.
Except that you have consistently sailed to show that runaway sexual selction DOES give better answers. I have shown most of your objections to be spurious.
quote:
Actually, I have asked you repeatedly for the explanation of long hair on the heads of humans, and this is the only answer you have provided. If that is not your answer for long hair, then you still have not answered that problem, which means that you are equivocating. "Retention of head hair" only means it would be like the hair on other apes. It isn't. It remarkably isn't. It fantastically isn't. Again your model falls short of explaining the actually observed features.
See, and you have the cheek to accuse me of straw men? I will lay out my reponse for you yet again.
1) My model does not claim to be able to explain absolutely every feature of human beings. I have never proposed an explanation of the vermiform appendix as arising due to running. Your Universalist requirement for any theory about SOME adaptations to be applicable to ALL adaptations is blatantly illogical and bad science.
2) I have never challenged the claim that long head hair is a sexual characterisitic. That does not however in any way imply that the loss of body hair is also a sexual characteristic. therefore, I am both willing an able to accept that the LENGTH of head hair is sexually slected, and simultansoulsy argue that the mere PRESENCE of head hair is an environmentalo adaptation.
3) Your presumption therefiore that the length of head hair is a disqualifier of my argument falls. My model predicts WHY IT IS HEAD HAIR that is available for sexual selection. My theory is better than yours.
quote:
This is consistently your problem: in spite of all the misrepresentations of my arguments and all the ad hominums, your model does not consistently explain the observed features and behavior of humans, and sexual selection does.
Sexual selection does not at all, and my model precisely predicts the presence of head hair. the LENGTH of that head hair is by no means a diusqualifier of the claim. And thus we see that this is consistently YOUR problem; you have been given this explanation multiple times and not once have you provided a crtiique or rejection - you just sit there shouting "you have failed to explain it". Thats blatant rubbish, isn it?
quote:
And now explain how this results in the hairier males that are doing the running that the hairlessness is being selected for while resulting in barer females? I could try to state this for you but you seem to go off the handle when I do: perhaps you could elucidate with clarity just exactly how this occurs?
Again, this is a question I have already answered. Are you really so stupid that you cannot imagine that conuntervailing strategies may rule out a truly optimum solution? Evolution does not occur in wind tunnels; the mobility granted by hairlesness is necessarily a trade off with the needs you find operational when you arrive at your destination. Nobody ever said that only males were doing the running. All I said was tha males were the primary combatants. We are talking about nomadic groups here, after all.
quote:
What you fail to understand (apart from my argument entirely, as it is here - again - totally misrepresented) is that I have never been on the ropes, and that I am very serious about this issue. I notice again that you dismiss the argument instead of address it.
HAHA. You are most certainly on the ropes, because the only way you can respond to my argumient is via straw men and misrepresentations. And I ask, what would be the point of addressing your argument in a single praragraph of a whole post addressing your argument?
If you would like to restate your argument for my better comprehension, if you disagree with that cited as I understand it in the post above in response to Pink Sasquatch, by all means do so.
It remains the case, however, that "srunaway sexual selection" explains fewer features of actual human anatomy than the running ape model. Runaway sexual selection is a very poor explanation.
quote:
{{I could, but I won't stoop to your level, in spite of the many such opportunities. Perhaps if you spent less time on gratuitous insults you would have more time to address the issues.}}
Then stop misrepresenting my arguments. If you want to be respected, behave in a respectworthy way.
Back to the laborious details:
quote:
{{False on several counts. One is that hair was already on the head, so existence there does not need to be explained. What needs to be explained is why it is the longest hair in the ape family by several factors much longer comparatively than the tail feathers of the scissortail bird compared to other birds of that size and weight.
you are miostaken. The presence of head hair DOES need to be explained - because it directly contradicts the general trend to hairlessness. It is precisely becuase we can see that the retention of hair on the head is functional, not accidental, that it's retention does NOT appear to have anything to do with sexual selection. The LENGTH of that hair CAN be explained by sexual selection - but not its presence.
quote:
This is not explained by your running model or your (newly added) armor model. This is adequately explained by runaway sexual selection just as the tail feathers are.
No, it is even PREDICTED by my model. In the article in which I read of the theory, it was one of the primary arguments advanced; that the retention of head hair required an explanation for which this was the best fit. Sexual selection explains nothing at all; the running ape idea both fits the data better and obviates the need for a self-referential non-explanation. Thus, it is a stronger argument.
quote:
Rather than two mechanisms (your version, oh, and your model is (now) two entirely different mechanisms isn't it?) there is one.
But seeing as there is every reason to expect that a real animal ion the real world will be undergoing multiple presssures, that it is not a menaingful objection.
quote:
Agreeing that long hair shows runaway sexual selection and then adamantly arguing that no other features show this aspect of selection is disingenuous at best.}}
Thats a lie, isn't it RAZD? At no time have I ever said that there definately are not any other features exhibiting sexual selection. I'm completely in agreement with notionas that breasts are sexually selected for example. ALL I have argued is that an adaptive model is a better explanation of hairlessness than sexual selection.
quote:
{{And again you fail to address the issue and rely on dismissal. Yes it is obvious.
It is entirely appopriate to dismiss something that is not an argument but an assertion. It may be obvious to YOU, but it may also be obvious to YOU that aliens built the pyramids.
quote:
Peacock tails are obviously selected in the male species. Bareness is obviously selected in the female species. Conversely, if the other sex displays the feature with wide variation between individuals, wider variation on each individual and to a lesser degree overall, then it is obviously a secondary expression of the selection.
But what you are still doing is baselessly ASSUMING that bareness is selected in the female rather than bareness is selected for in both, with a countervailing pressure for the retention of hair in males. Once again your model is implistic, isolating the organism from all environmental pressures. Thats weak; much weaker than the running ape model.
quote:
{{As noted previously, dancing exhibits more fitness in more areas to a greater degree than just running (see previous post for the "rundown" on it). As just one example, running does not display creativity, while dancing does. Dancing displays fitness for (A,B,C and D) while running displays fitness for (A). This is an inductive logical error to think that running is more descriptive of fitness than dancing.}}
Nope, straw man. I never said that the demosntration of running was as comprehensive a demonstration of sexual attractivesness as dance. All I argued was that dance is necessarily a pedal motion, and even in animals with no meaningful creativity, dance-type behaviours are observed. That is, it can reasonably be seen as a basic demonstration of running fitness, by displaying balance, dexterity, fleetness of foot, precision - AND also the mental functions such as creativity and others. I have not ever argued against dance being sexual selection in action - I have only argued against the proposition that DANCE explains bipedalism or rules out running as a mode of production. The basic fucntion of bipeadlism is running; dance is a non-running behaviour delivered by the same meachanisms.
quote:
{{Yeah, who was that guy that won the first "American Idol" competition? And Stevie Nicks, Queen Latifa, Mama Cass and etcetera are just second class talent that couldn't pack an auditorium}}
Yes - an obese woman won pop idol too. then her caree sank like a stone. And mama cass is almost mentioned as the archetypcal artist who will never be seen again for precisely that reason.
om shaved pornstars: [quote] {{False. Evidence that supports the conclusion that it is bareness that is sexy.}}[/qupte]
Nope, thats assuming the conclusion, becuase simply not obstructing the view is a more parsimonious explanation. It has not escaped you that porn is a visual medium, I trust?
quote:
{{Actually the more attractive ones look better than runners because they appear adequately fed, healthy and creative: strong reasons to be good mate material.}}
Adequately fed, like a good hunter perhaps? But your argument gets even weaker, becuase of course people who live in conditions more like those of hunter-gatherers carry much less body fat that modern westerners. That is, normal individuals in those societies look more like runners than they look like dancers in our societies. This is a sugar-free environment, lets not forget.
quote:
{{And yet seasonal variation is curiously lacking in humans, specific reference is made again to the Inuit people, that could benefit most from a little variation and where cooling is not necessary anymore.}}
I'm aware seasonal variation is lacking in humans - its almost unioticabel on the african savannah, for the most part, as I have already mentioned. Nonetheless you are again misrepresenting my argument and trying to bait-and-switch it onto another topic - as you know, what I was demmonstarting was that the relation between hair and temperature regulation is inherent to mammals.
I read the Innuit only arrived in there present location at about 1000AD, so they have only had about a thousand years to evolve. Isn;t that a bit ambitious? Even if we assumed there were genes running back to the first human colonisers of this nich, this would only give 4,5000 years. Furthermore, according to the running ape model, we would expect to see the polar reagions being the last colonised, because they are the regions to which humans are least adapted and thus require the most technical intervention - chief among these being clothes and fire. And that indeed is what we see.
quote:
{{Why? Because you miss the point that the argument is about selection of bareness in humans and not about baleen in whales or thick coats of fur with closed air cells in cariboo?}}
Except you fail to recognise that the entire debate is about WHETHER they are relevant or not. you are not permitted to assume your own conclusion and then insist that the entire "debate" be conducted in that light. Furthermore, it is an entirely appropriate response to YOUR claim that my explanation failed to explain certain features; as you pointed out, this spoke to the consistency of the model. Now I have demonstarted that YOUR model leaves many features unexplained, and thus undermines the consistency of your model. Turnabout is fair play.
quote:
ps - how do you explain art (all forms) as a result of evolution?
Start a different thread on that topic if you want to discuss it.
Now, to satisfy Pink Sasquatches interventionist urges, and to provide yet more material for RAZD to "debunk", I offer the following:
Human Thermoregulation and Hair Loss - Modern Human Origins claims that:
quote:
The sweating mechanism of modern humans is the single most important thermoregulatory device available to reduce heat load on the body and likely has coevolved with the loss of body hair in the human lineage. Sweating is a thermoregulatory mechanism of modern humans that effectively removes body heat through evaporation. It becomes extremely effective in the absence of heavy body hair, and actually can be maladaptive in the presence of heavy hair cover.
... and
quote:
Evaporative heat loss through the use of the eccrine gland system in humans is extremely effective at removing unwanted body heat. Evaporative heat loss occurs through the secretion of sweat primarily made of water, the heat exchange from the skin (that is artificially maintaining a larger proportion of heat due to the highly developed vascular system that moves heated blood from the body core to the surface at high rates) into the sweat, and the evaporation of the sweat as it is either sloughed off or evaporated into the air. Effective sweating requires as little hair cover as possible, as it needs air contact (particularly moving air) over the skin to remove the heated sweat. In an individual with a prodigious sweating mechanism and dense hair cover, the heated sweat will generally be retained by the hair cover and actually begin to act as insulation preventing heat loss, leading to hyperthermia. Non-evaporative conduction becomes less and less effective with increased body size (due to the decreasing surface area to body size ratio) and with increased ambient temperature (due to a lower temperature difference between the environment and the organism) making evaporative heat loss through sweating an extremely important adaptation in the relatively large bodied ancestors of humans in the warm climate of Africa (Robertshaw 1985; Schwartz and Rosenblum 1981).
and...
quote:
Sexual Selection: The idea that the loss of body hair in the human lineage was a result of sexual selection is a very old one. Darwin first presented the idea in 1871 (though a footnote in the text attributes the idea - inspiration? - to Reverend T.R. Stebbing) in a text on sexual selection, which Darwin believe worked in concert with natural selection in the evolution of species. Darwin's original reasoning can be considered faulty in retrospect ("no one supposes that the nakedness of the skin is of any direct advantage to man; his body hair therefore cannot have been divested of hair through natural selection"), but some of his observations are still considered to hold true. For example, the facial hair of men has no functional or adaptive significance that can be explicated. It is a plausible explanation for the differences between male and female facial hair is sexual selection, or possibly the difference in body hair in males and females. However, invoking sexual selection as the cause of the loss of body hair in humans encounters several hurdles.
The presence of an effective sweating mechanism for evaporative heat loss is greatly dependent on the loss of body hair in humans. If sexual selection is ultimately responsible for the loss of body hair in humans, the sweating mechanism would have to have been selected for by a separate mechanism, even though the two features would have had to develop in concert for sweating to remain effective. This is not in any way impossible, as it might be argued that the sexual selection leading to hair loss would have allowed the selection for an efficient sweating mechanism. In this scenario, sexual selection would not even have to be the main driving force of the loss of body hair; it would at the very least only be required to initiate the reduction in body hair, at which point natural selection for the thermoregulatory efficiency of the sweating mechanism might drive the denudation of the human lineage. This is not unreasonable and therefore is an open option even when discussing the selective benefits of sweating as the driving force in the loss of body hair in humans. However, while it is an option that cannot be negated, the invoking of two selective pressures to explain a single phenomenon when one can explain it just as well makes the explanation less parsimonious, though not necessarily unlikely or unreasonable.
While http://www.fortunecity.com/emachines/e11/86/human.html says:
quote:
Many mammals have complex chambers with moist linings in the nose and a heat exchange system to keep the blood cool as they pant to speed up evaporation. This was not an option for early hominids as they did not have a muzzle in which to house a cooling system. However, an upright posture would solve many of the problems, especially combined with a reduction in body hair. Upright walking means that less of the body surface is exposed directly to the sun at midday, while heat can be lost faster and any breezes are more likely to cause evaporation of sweat and so cool the body down. Retaining hair on the top of the head and perhaps the shoulders acts as a shield for the areas directly exposed to the sun.
An improved ability to control body temperature would mean that our ancestors could forage around midday, when there was less competition and fewer predators nearby. If this is correct, hair loss probably occurred relatively early in evolution, and is linked to bipedalism.
It was a very successful lifestyle. Unlike the other apes, the australopithecines could venture into the savannah from the wooded riverbank areas which were probably their preferred habitat. They spread as far south as South Africa, and they developed over the next 2 million years into a number of different types. Some gave rise to humans, but long after humans began to make tools, there were still australopithecines wandering the African savannah. Some species, the robust australopithecines, developed huge grinding teeth, and muscles for chewing so large that they had to be attached to crests of bone running front to back on their skulls as well as wide, flared cheek bones.
while Hair - Wikipedia says:
quote:
One theory suggests that nature selected humans for little body hair as part of a set of adaptations including bipedal locomotion and an upright posture. Bipedal locomotion is extremely inefficient, and many animals can outrun human beings for short periods of time; such animals, however, are inefficient radiators of heat, and cannot run for long periods of time (notable exceptions include most cursorial animals, including savannah fauna). Thus, human hunters must be able to chase animals for long periods of time, and must therefore have an efficient mechanism for radiating body heat. Upright posture exposes less surface area of the body to direct solar radiation, and subcutaneous sweat glands developed, providing such a cooling mechanism. A more recent theory for human hair loss has to do with a possible period of bipedal wading in a salt marsh in the Danakil region of Ethiopia, which occurred in the hominid lineage, between 5 and 7 million years ago. As a wading animal, it was more efficient to develop short body hair and a layer of subcutaneous fat for streamlining and insulation in the aquatic environment; the eccrine sweat glands developed later after the hominids left the water. This is why most hairless mammals are aquatic (dolphins, dugongs, whales), had an aquatic period in their pasts (elephants, rhinoceroses, pigs) or have very short fine fur because of brief periods back out of the water (seals, sea lions). There is a hypothesis that claims humans are no exception to this rule of hairlessness through means of a marine transition; see Aquatic Ape Theory.
Typically, humans have more hair on the top of the head, because this region of the body was exposed to solar radiation at all times, even when wading, and also hair where extremities meet the torso (axillary (arm-pit) hair, and pubic hair), on the eyelids and above them (eyebrows). In most societies people shave, style or adorn their hair for aesthetic reasons.
It is absolutely unacceptable for you, RAZD, to assert that this is an idea I have simply sucked out of my thumb. It is a genuine proposition which meets ALL your objections. *I* find it satisfying; I have *not* asserted it is is an undeniable and obvious truth. It is a *suitable* counter-argument to your assertion that hairlessness is ONLY and EXCLUSIVELY sexually selected and that there are not other hypthosese on the matter. There are. Deal with it.

This message is a reply to:
 Message 128 by RAZD, posted 01-25-2005 10:15 PM RAZD has replied

Replies to this message:
 Message 134 by RAZD, posted 01-26-2005 9:16 PM contracycle has replied

pink sasquatch
Member (Idle past 6271 days)
Posts: 1567
Joined: 06-10-2004


Message 133 of 161 (180828)
01-26-2005 12:47 PM
Reply to: Message 131 by contracycle
01-26-2005 4:56 AM


Re: And the winner is ... RAZD?
Of all the arrogant bullshit...
Nice... you post some "evidence" (seemingly?) unrelated to the topic at hand and it's somehow my fault.
Therefore it is entirely accurate to demonstrate the other evidence that corroborates the running ape model and which contributes to the model as a whole.
Two of your the thirteen points you list involved cooling. None of them mention hair.
Thus the "running ape model" which you seem to be referencing doesn't include references to hairlessness.
The discussion is sexual selection of hairlessness.
I still don't see why RAZD needs to explain, say, stabilization by "huge" buttocks size, with his argument of sexual selection of hairlessness.
As RAZD has been at pains to point out, what matters is consistency with all observed phenomenon.
Sexually selected hairlessness is not inconsistent with independent, fitness-based evolution of the other features you listed above that contribute to a running ape model. If it is, please explain specifically how.
I'll check out the websites you quote in your response to RAZD - they seem more to the point, and on my quick scan I noticed that one states that sexual selection may have played a major role in the loss of hair.
And as far as me being an "interjectionist", if you want to have a one-on-one debate with RAZD, move it to a Great Debate topic. This is an open discussion forum.

This message is a reply to:
 Message 131 by contracycle, posted 01-26-2005 4:56 AM contracycle has replied

Replies to this message:
 Message 135 by contracycle, posted 01-27-2005 4:48 AM pink sasquatch has not replied

RAZD
Member (Idle past 1654 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 134 of 161 (180957)
01-26-2005 9:16 PM
Reply to: Message 132 by contracycle
01-26-2005 6:15 AM


{proposition}
I have read your post. I have also read pink sasquatch's post. The main conclusion I come to is that this nit-picking debate is not working for either of us - each feels that the other badly misunderstands\misrepresents the other, and concentrates on "correcting" that to the point of interfering with the discussion.
Let me make a proposition to you: Let us work on understanding each other's argument {before\without} attacking it -- and as honestly as possible.
In other words you can state what you think my position is and I will {adjust\correct} that until we can both agree on an understanding of the proposed process.
I will state what I think your position is and you will {adjust\correct} that until we can both agree on an understanding of the proposed process.
Then once we have the two mechanisms defined to the satisfaction of each we can then look at (and taking the time to agree on each one before proceeding to the next):
(1) The application of each to beginning the bareness selection process: how do you start the ball rolling.
(2) The likely development of the bareness feature in the early hominids in Africa as a result of each process (what would the models predict for bareness).
(3) The disparities between the model predictions and the observations (or what we can assume from current expression of the bareness feature to have been the case then, seeing as we don't really have that information).
(4) The possibility of inter-related selection processes (running and sexual selection).
(5) The application of each process to the current (ongoing) selection.
In the spirit of working together to reach an understanding, if not an agreement, I offer this proposal as a first step for the {adjust\correct} process: feel free to {edit\add\delete} what you feel is {needed\appropriate\innappropriate} in this proposal so that we can have an agreed on process for continuing.
I further suggest:
That the subtitle of this subthread be kept as {proposition} and that it is purely for discussing this process.
That the subthread for defining the running ape process be called {running ape process definition} and that it is purely for defining the process and not attacking it.
That the subthread for defining the sexual selection process be called (sexual selection process definition} and that it is purely for defining the process and not attacking it.
Further subthreads to be defined at the beginning of each one (such as for (1) above as {how bareness began} and the like).
I trust we can have the support of {admin} on this as it is establishing the {procedure\ground rules} for the discussion to proceed in a civilized manner.
My hand is out (palm up to show that it is free of weapons), let us work on educating each other rather than on making enemies eh?

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

This message is a reply to:
 Message 132 by contracycle, posted 01-26-2005 6:15 AM contracycle has replied

Replies to this message:
 Message 136 by contracycle, posted 01-27-2005 5:44 AM RAZD has replied

contracycle
Inactive Member


Message 135 of 161 (181030)
01-27-2005 4:48 AM
Reply to: Message 133 by pink sasquatch
01-26-2005 12:47 PM


Re: And the winner is ... RAZD?
quote:
Nice... you post some "evidence" (seemingly?) unrelated to the topic at hand and it's somehow my fault.
If you mount illogical arguments and distoirt the context of others arguments, it is indeed your fault.
quote:
Two of your the thirteen points you list involved cooling. None of them mention hair.
And as you will read, if you can be bothered, that is directly related to sweating. We are hairless to facilitate sweating - which is a thermal control mechanisms. All of this has been perfectly consistent with my very first argument.
quote:
The discussion is sexual selection of hairlessness.
Is that so Sasquatch? Then why does the topic line not read "the sexual selection of hairlessness?" Don't you find that a bit odd?
In fact the topic read "the evolution of clothes?".
quote:
Sexually selected hairlessness is not inconsistent with independent, fitness-based evolution of the other features you listed above that contribute to a running ape model. If it is, please explain specifically how.
Gah, ahve you actually read anything I've posted? Seeing as I have already been quite happy to allow sexual selection to occur siimultaneously with the running ape model, why on earth do you ask this stupid question? I never said they were incompatible at all, I said they WERE compatbible. RAZD claimed that they were not compatible, and that hairlessness was exclusively due to runaway sexual selection. Please direct your question to RAZD and do as all the courtesy of actually reading the thread you seek to comment on.
quote:
I'll check out the websites you quote in your response to RAZD - they seem more to the point, and on my quick scan I noticed that one states that sexual selection may have played a major role in the loss of hair.
Sure. But why do you think that would be surprising to me? I've consistently argued that we are being sexually selected for running fitness - that the two pressures are sympathetic. That we recognise sexiness by its proximity to a "running ape" ideal. AND I pointed out that this was far more frtuiful a line of thought than just tossing it under "runaway" sexual selection without purpose or meaning or functionality.
quote:
And as far as me being an "interjectionist", if you want to have a one-on-one debate with RAZD, move it to a Great Debate topic. This is an open discussion forum
Fair enough. But then read the thread and respond to the points actually being made.

This message is a reply to:
 Message 133 by pink sasquatch, posted 01-26-2005 12:47 PM pink sasquatch has not replied

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