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Author Topic:   why is the lack of "fur" positive Progression for humans?
arrogantape
Member (Idle past 1996 days)
Posts: 87
Joined: 09-26-2008


Message 151 of 202 (509088)
05-18-2009 4:01 PM
Reply to: Message 150 by bluescat48
05-18-2009 1:46 PM


Re: woodland forest apes and bareness selection
Bluescat48, we ain't bars.

A quote:

"Tolkien's hobbits walked an awful long way, but the real "hobbit", Homo floresiensis, would not have got far.

Its flat, clown-like feet probably limited its speed to what we would consider a stroll, and kept its travels short, says Bill Jungers, an anthropologist at the State University of New York in Stony Brook."


This message is a reply to:
 Message 150 by bluescat48, posted 05-18-2009 1:46 PM bluescat48 has responded

Replies to this message:
 Message 152 by bluescat48, posted 05-18-2009 5:08 PM arrogantape has not yet responded

    
bluescat48
Member (Idle past 1544 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 152 of 202 (509091)
05-18-2009 5:08 PM
Reply to: Message 151 by arrogantape
05-18-2009 4:01 PM


Re: woodland forest apes and bareness selection
arrogantape writes:

Homo floresiensis, would not have got far.

What evidence, might I ask, do you have?


There is no better love between 2 people than mutual respect for each other WT Young, 2002

Who gave anyone the authority to call me an authority on anything. WT Young, 1969

Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008


This message is a reply to:
 Message 151 by arrogantape, posted 05-18-2009 4:01 PM arrogantape has not yet responded

    
arrogantape
Member (Idle past 1996 days)
Posts: 87
Joined: 09-26-2008


Message 153 of 202 (509108)
05-18-2009 6:22 PM


That was a quote from New Science.

Here i another quote from Anthropology.net This one concerns H Floresiensis's archac wrist:

-------------------------------------------------------------------

"The Flores scaphoid shape and articular surfaces are more triangular in shape and lacks the larger articular surface on the palmar side which is seen in modern humans and Neandertals. Curiously, the scaphoid also has a fused centrale; a condition seen in H. habilis."

---------------------------------------------------------------------

Now the Hobbit shares a strikingly similar skull to H Habilis found in Africa, and also the same wrist bone configuration.

I am just waiting for some anthropologist to echo my educated guess what the clown feet were good for.

I would like archeologists to dig deep in every coastal cave around India, and Africa.


    
RAZD
Member
Posts: 18242
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 154 of 202 (509371)
05-20-2009 10:25 PM
Reply to: Message 149 by arrogantape
05-18-2009 11:32 AM


Re: woodland forest apes and bareness selection
Hi arrogantape

I am going to have to work on the procedures to upload photos,...

You will need a site to host your pictures. I use
http://www.imageshack.us/
It's free, relatively easy to use, and I haven't run out of capacity yet.

Then you need to find the site's url for your picture and insert it like this:

[thumb=300]http://img84.imageshack.us/img84/8168/dscf2528gr0.jpg[/thumb]

the 300 is the pixelwidth of the thumbnail, thumbnails are always centered and you can post a large picture but have it take up a small part of the post with this feature. The above example becomes


Click to enlarge

... and outside quotes.

You can usually copy and post the link (as I did above for the imageshack website. For long urls you'll need to do a little more:

[url=http://www.sciencedaily.com/releases/2009/05/090506144307.htm]'Hobbits' Couldn't Hustle: Feet Of Homo Floresiensis Were Primitive But Not Pathological[/url]

'Hobbits' Couldn't Hustle: Feet Of Homo Floresiensis Were Primitive But Not Pathological

[quote]quotes are easy[/quote] becomes:

quote:
quotes are easy

Combining this we get:

quote:

Click to enlarge

A detailed analysis of the feet of Homo floresiensis—the miniature hominins who lived on a remote island in eastern Indonesia until 18,000 years ago—may help settle a question hotly debated among paleontologists: how similar was this population to modern humans?

A new research paper, featured on the cover of the May 7 issue of Nature, may answer this question. While the so-called "hobbits" walked on two legs, several features of their feet were so primitive that their gait was not efficient.

But a number of recent analyses of the skull, face, and wrist have found many unusually primitive features among the "hobbits" that are more similar to chimpanzees and Australopithecus, suggesting that the Flores inhabitants represent a remnant population of early hominins.

The anatomy of the foot described in the new paper might finally answer the pathological modern vs. primitive population question. Although the foot is characteristic of a biped—being stiff and having no opposable big toe—many other traits fall outside of the range for modern humans. The H. floresiensis foot is very long in proportion to the lower limb and considerably more than half the length of the thighbone; modern human feet are relatively shorter at about half of the femur's length. The stubby big toe of the hobbits is another primitive, chimp-like trait. But the pivotal clue comes from the navicular bone, an important tarsal bone that helps form the arch in a modern human foot. The "hobbit" navicular bone is more akin to that found in great apes, which means that these hominins lacked an arch and were not efficient long-term runners.


If the foot of H. floresiensis is 30% bigger that a proportional H. sap (or H. erectus) which are 30%+ bigger than H. floresiensis ... could it not be that the foot is retained while the rest became smaller?

Are you Jim Moore or do you know him? Just curious (that's me in the first picture)

Enjoy.

ps -- still no answer on the sexual dimorphism eh?


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 149 by arrogantape, posted 05-18-2009 11:32 AM arrogantape has responded

Replies to this message:
 Message 155 by arrogantape, posted 05-21-2009 10:10 AM RAZD has responded

  
arrogantape
Member (Idle past 1996 days)
Posts: 87
Joined: 09-26-2008


Message 155 of 202 (509409)
05-21-2009 10:10 AM
Reply to: Message 154 by RAZD
05-20-2009 10:25 PM


Re: woodland forest apes and bareness selection
Hi RAZD,

What answer do you want from me on sexual dimorphism? Yes, it exists. If you are alluding to modern male and female differences, yes, indeed, there are remarkable differences. The female of our species is smoother skinned.

You are assuming our species is the end product of a steady progression. I don't buy that. We could have inherited the naked trait, and the bipedal mode of moving about, plus tool making from our distant semi aquatic ancestors. Then, with the move inland, larger size, and more efficient land travel was needed for survival. Sexual dimorphism, no doubt, progressed too.


This message is a reply to:
 Message 154 by RAZD, posted 05-20-2009 10:25 PM RAZD has responded

Replies to this message:
 Message 156 by RAZD, posted 05-21-2009 9:59 PM arrogantape has responded

    
RAZD
Member
Posts: 18242
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 156 of 202 (509450)
05-21-2009 9:59 PM
Reply to: Message 155 by arrogantape
05-21-2009 10:10 AM


Re: woodland forest apes and bareness selection
Hi arrogantape

What answer do you want from me on sexual dimorphism? Yes, it exists. If you are alluding to modern male and female differences, yes, indeed, there are remarkable differences. The female of our species is smoother skinned.

So how did this dimorphism evolve if aquatic adaptation is the cause for loss of terminal hair?

If you use aquatic adaptation to explain the evidence of smoother appearing skin, then you must explain the dimporphism, or you have explained one sex and not the other.

You are assuming our species is the end product of a steady progression.

Not at all, just that there is a survival or reproductive benefit to the adaptation of new traits.

We could have inherited the naked trait, and the bipedal mode of moving about, plus tool making from our distant semi aquatic ancestors.

There is no evidence of any semi-aquatic ancestors. There is evidence of woodland jungle apes and Savannah apes. There is no evidence of tools developed to use in a marine environment. There is evidence of tools developed to use in a Savannah environment and one mixed with pockets or woodland jungle.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 155 by arrogantape, posted 05-21-2009 10:10 AM arrogantape has responded

Replies to this message:
 Message 157 by arrogantape, posted 05-22-2009 12:35 PM RAZD has acknowledged this reply
 Message 158 by Blue Jay, posted 05-22-2009 5:22 PM RAZD has responded

  
arrogantape
Member (Idle past 1996 days)
Posts: 87
Joined: 09-26-2008


Message 157 of 202 (509563)
05-22-2009 12:35 PM
Reply to: Message 156 by RAZD
05-21-2009 9:59 PM


Re: woodland forest apes and bareness selection
A florensies is now regarded as a primitive hominid. This creature enjoyed easy pickings on the island of Flores. It did have tools, rather advanced tools at that. Their feet precludes any notion they were land travelers, and that they came by water to that island. There were enough of them to keep a colony going for many thousands of years. Besides the easy land animals they devoured, they also had fish, frogs, and other water born creatures in their diet.

There has to be a biological reason for changes. Our females are barer than we males. Like I said before, though, my skin dries quickly, after a swim as my wife's. We are not as densely fur clad as our ape brethren. Some males have little more noticeable hair as women. 200 thousand years can obscure our beginnings.

I think that this debate has run it's course on these pages, save for another discovery relighting the fire. You can be sure H floriensis will start the debate among scientists. I am googling for that to happen.


This message is a reply to:
 Message 156 by RAZD, posted 05-21-2009 9:59 PM RAZD has acknowledged this reply

Replies to this message:
 Message 160 by lyx2no, posted 05-22-2009 6:20 PM arrogantape has responded

    
Blue Jay
Member (Idle past 53 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 158 of 202 (509594)
05-22-2009 5:22 PM
Reply to: Message 156 by RAZD
05-21-2009 9:59 PM


Re: woodland forest apes and bareness selection
Hi, RAZD.

RAZD writes:

So how did this dimorphism evolve if aquatic adaptation is the cause for loss of terminal hair?

If you use aquatic adaptation to explain the evidence of smoother appearing skin, then you must explain the dimorphism, or you have explained one sex and not the other.

Looking at this from a genetics perspective, I don't think this statement is accurate. According to Wikipedia, sexual dimorphism in body hair pattern is due to the activity of androgens, which produce more body hair in males.

If Wikipedia is correct, then there seems to be at least two different genetic mechanisms at work, one that explains the sexual dimorphism, and one that explains the difference between us and the other apes.

These two mechanisms need not even be linked at all. So, I don't think Ape actually has to explain the dimorphism in order to explain the "hairlessness."


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 156 by RAZD, posted 05-21-2009 9:59 PM RAZD has responded

Replies to this message:
 Message 159 by RAZD, posted 05-22-2009 5:59 PM Blue Jay has responded

  
RAZD
Member
Posts: 18242
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 159 of 202 (509601)
05-22-2009 5:59 PM
Reply to: Message 158 by Blue Jay
05-22-2009 5:22 PM


Re: woodland forest apes and bareness selection
Hi Bluejay

If Wikipedia is correct, then ...

It explains how the specific dimorphic pattern occurs, but not why it occurs.

There is still plenty of variation in body hair in males, that active selection for less body hair phenotypes to operate in the population, and then those males would be preferentially selected for. There is still plenty of variation in body hair in males, that active selection against particularly hairy male phenotypes to operate in the population, and then those males would be preferentially selected against. From the continued degree of variation within the population it is evident that there is no strong selection pressure one way or the other on male hair patterns.

There is still active selection of less body hair in females, however now it is achieved with tools instead of genes.

http://www.visit4info.com/brand/Gillette-Womens-Razors-Blades-Range/3298

Obviously this sexual selection is still going on. Interestingly, several experiments have shown that one of the markers of run-away sexual selection is that a trait is driven to one end of the spectrum, and that artificially enhanced specimens that are made outside of what is possible within a population, will be actively sought for mating.

Curiously, the main areas where women shave these days includes their legs, where female terminal hairs normally grow, and which would be most effected by an aquatic adaptation.

These two mechanisms need not even be linked at all. So, I don't think Ape actually has to explain the dimorphism in order to explain the "hairlessness."

The question is still why that particular genetic adaptation was selected for, rather than one that would provide universal and equal loss of terminal hair.

Enjoy.

ps - buy stock in razor companies ... and shave your losses ...

Edited by RAZD, : clrty

Edited by RAZD, : gleshin


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 158 by Blue Jay, posted 05-22-2009 5:22 PM Blue Jay has responded

Replies to this message:
 Message 161 by Blue Jay, posted 05-22-2009 6:35 PM RAZD has responded

  
lyx2no
Member (Idle past 2071 days)
Posts: 1277
From: A vast, undifferentiated plane.
Joined: 02-28-2008


Message 160 of 202 (509602)
05-22-2009 6:20 PM
Reply to: Message 157 by arrogantape
05-22-2009 12:35 PM


De feet
Their feet precludes any notion they were land travelers
Other then your claim, the only foot structure related limitation I've been able to find is that they would have been less efficient runners then we. If, as you say, "This creature enjoyed easy pickings on the island of Flores." would having been not particularly fleet of foot have been a significant impediment?

Have you anything to support your repeated intimation that H. floresiensis might as well have been a penguin in the Tsingy karst?


Click to enlarge

Edited by lyx2no, : Insert "Tsingy".

Edited by lyx2no, : Fix some rather atrocious grammar.


It is far easier for you, as civilized men, to behave like barbarians than it was for them, as barbarians, to behave like civilized men.
Spock: Mirror Mirror

This message is a reply to:
 Message 157 by arrogantape, posted 05-22-2009 12:35 PM arrogantape has responded

Replies to this message:
 Message 162 by arrogantape, posted 05-22-2009 8:58 PM lyx2no has responded

  
Blue Jay
Member (Idle past 53 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 161 of 202 (509605)
05-22-2009 6:35 PM
Reply to: Message 159 by RAZD
05-22-2009 5:59 PM


Re: woodland forest apes and bareness selection
Hi, RAZD.

RAZD writes:

It explains how the specific dimorphic pattern occurs, but not why it occurs.

It shows a mechanistic distinction between dimorphism and "hairlessness." Whether or not the two mechanisms are linked is now the question that should be addressed.

-----

RAZD writes:

From the continued degree of variation within the population it is evident that there is no strong selection pressure one way or the other on male hair patterns.

This would be true, no matter what the original cause was. There is currently no strong selection pressure on thermoregulatory ability or swimming ability, either, which is equally compatible with the existing variation in hair pattern.

-----

RAZD writes:

There is still active selection of less body hair in females, however now it is achieved with tools instead of genes.

This could get into a chicken-and-egg scenario: we could just as easily have become "naked" first by some other mechanism, and only afterwards have associated "nakedness" with female sexuality because of the differences due to hormone activity.

-----

RAZD writes:

The question is still why that particular genetic adaptation was selected for, rather than one that would provide universal and equal loss of terminal hair.

How can I answer the question, "Why didn't X happen?"

Why didn't snakes on the African savannahs develop rattles to warn ungulates not to step on them, as snakes in North America did?

However, since the development of terminal hairs seems to be tied to male hormones, total nakedness would seem to incur reproductive costs on males. Thus, the existing pattern may be a compromise between thermoregulation and hormonal requirements for reproduction.


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 159 by RAZD, posted 05-22-2009 5:59 PM RAZD has responded

Replies to this message:
 Message 163 by RAZD, posted 05-22-2009 9:34 PM Blue Jay has responded

  
arrogantape
Member (Idle past 1996 days)
Posts: 87
Joined: 09-26-2008


Message 162 of 202 (509614)
05-22-2009 8:58 PM
Reply to: Message 160 by lyx2no
05-22-2009 6:20 PM


Re: De feet
lyx2no

Funny you should mention the word penguin in reference to my take on h Floriensis, who would have walked similarly to the flat footed penguin. H f. had to have picked up the knee considerably more than we do. The papers say H f. was no runner, either fast, or slow.

Flores is a closed system. There were no big predators. If H f. was smart enough to make a stone dagger, he was smart enough to trap his prey. Running was not necessary, and h F. was a ridiculous runner any way.

The big flat feet are ideal for water propulsion. The question that needs to be answered is, was H f.'s closest kin, H habilis, flat footed?


This message is a reply to:
 Message 160 by lyx2no, posted 05-22-2009 6:20 PM lyx2no has responded

Replies to this message:
 Message 165 by lyx2no, posted 05-23-2009 1:24 AM arrogantape has responded

    
RAZD
Member
Posts: 18242
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 163 of 202 (509615)
05-22-2009 9:34 PM
Reply to: Message 161 by Blue Jay
05-22-2009 6:35 PM


Re: woodland forest apes and bareness selection
Hi Bluejay,

However, since the development of terminal hairs seems to be tied to male hormones, total nakedness would seem to incur reproductive costs on males.

That doesn't explain the existence of males with hair similar to females, and they appear to be rather robustly represented in the population. Thus it would appear that the reduction of hair on males is not a hindrance to reproduction. It also does not seem to be undesirable: google male models.

If reproduction is not hindered, then the androgen theory fails to explain why the apparent hairlessness of males and females is different.

Female "bareness" is consistent in 99.9% of the female population in a highly skewed distribution.

Male "bareness is variable from one end to the other and has a relatively "normal" distribution in the population.

One distribution indicates selection, the other does not. It is the distribution of the traits in the population that shows that female bareness is a result of selection. The variation seen in males is due to secondary effects of the selection in females, effects that have neither positive nor negative consequences for reproductive success.

Enjoy


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 161 by Blue Jay, posted 05-22-2009 6:35 PM Blue Jay has responded

Replies to this message:
 Message 166 by Blue Jay, posted 05-23-2009 11:38 AM RAZD has responded

  
Jon
Inactive Member


Message 164 of 202 (509617)
05-22-2009 10:54 PM


Case Closed!
Where's the fight? Is it so un-obvious to folk? Females do not have full hair development because less-hairy females were selected as they resemble younger women, i.e., those with a longer potential future mating period.

I would not be surprised to discover this selection factor reaching all the way back past H. erectus. The attractiveness of a female with a longer future mating potential is so overwhelmingly greater than one with a shorter future mating potentialespecially in pre-civilized society/groups with high infant mortality and horribly lengthy gestation periods. Therefore, any females who can even resemble the younger ones, i.e., pass themselves off as one, will receive more mating attention.

Can the matter be put to rest now? Good lord!

Jon


You've been Gremled!
  
lyx2no
Member (Idle past 2071 days)
Posts: 1277
From: A vast, undifferentiated plane.
Joined: 02-28-2008


Message 165 of 202 (509627)
05-23-2009 1:24 AM
Reply to: Message 162 by arrogantape
05-22-2009 8:58 PM


The Question Is
The question that needs to be answered is, was H f.'s closest kin, H habilis, flat footed?
Actually, the question that needs to be answered is: do you have anything more than Jungers' glib statement in a news article for NewScientist from your Message 151? (It would be nice if you'd tell us where you get your quotes.)

Why didn't you use nature's take on H. floresiensis' running capacity:

quote:
For instance, because the foot lacks a well-defined medial longitudinal arch, recovery of stored elastic energy would have been limited in comparison with modern humans, especially during running, when mass-spring mechanics replace the pendular mechanics of walking. With a short hallux, relatively long lateral rays and a weight-bearing navicular tuberosity, pressure transfer through the foot in support phase and at toe-off also probably differed from modern humans. Kinematic differences related to clearance of the foot in swing phase would have been evident during both walking and running. The foot of H. floresiensis was not well-designed for either
high-speed or efficient endurance running.

Wasn't it dramatic enough to support your conformation bias? Note that it says H. floresiensis would have had evident kinematic differences during both walking and running; not "during waddling like a penguin with bunions"? Now, why do you think they'd bother to mention running if they were under the impression that H. floresiensis couldn't run at all, at all? They didn't mention H. floresiensis' shoulder structure would have hindered its ability to fly.

Do you have anything from Jungers' (or any) scientific papers to support your contention of H. floresiensis' sub-par abilities to use its own feet to eke out a living on land?

AbE: I just realized this is all off topic as I was wondering why RAZD and Bluejay kept going on about hair. One would think the "fur" bit in the title would have clued me, but no. Don't bother answering me, aa. I'll get about my way.

Edited by lyx2no, : Grammar.

Edited by lyx2no, : Sorry, OT.

Edited by lyx2no, : Typos-n-stuff.


It is far easier for you, as civilized men, to behave like barbarians than it was for them, as barbarians, to behave like civilized men.
Spock: Mirror Mirror

This message is a reply to:
 Message 162 by arrogantape, posted 05-22-2009 8:58 PM arrogantape has responded

Replies to this message:
 Message 167 by arrogantape, posted 05-23-2009 12:41 PM lyx2no has responded

  
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