shadow

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Posts by shadow

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  32

  Evolution Gap - Where's the Fur? Redux

  by shadow in

  1. watchtower
  2. beliefs

  i am posting a second topic on this subject since the first one became overrun by snakes.. cofty posted a link to a published paper discussing this topic and referred to the information in it as "facts".

  here is my summary of that paper along with comments on it.. one of the opening statements says that:.

  two frequently debated aspects of hominin evolution are the development of upright bipedal stance and reduction in body hair.. so for those who believe this is a stupid topic, it is a subject of interest to many stupid people including the authors of the paper referred to by cofty.

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  shadow

  topics posted by one user and the support used for those topics. perhaps the statement is clearer now
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  32

  Evolution Gap - Where's the Fur? Redux

  by shadow in

  1. watchtower
  2. beliefs

  i am posting a second topic on this subject since the first one became overrun by snakes.. cofty posted a link to a published paper discussing this topic and referred to the information in it as "facts".

  here is my summary of that paper along with comments on it.. one of the opening statements says that:.

  two frequently debated aspects of hominin evolution are the development of upright bipedal stance and reduction in body hair.. so for those who believe this is a stupid topic, it is a subject of interest to many stupid people including the authors of the paper referred to by cofty.

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  shadow

  Along with the mandatory biology and chemistry university courses I took one focused exclusively on evolution and debated a number of times with the professor. I don't recall the books used since that was over 20 years ago.
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  32

  Evolution Gap - Where's the Fur? Redux

  by shadow in

  1. watchtower
  2. beliefs

  i am posting a second topic on this subject since the first one became overrun by snakes.. cofty posted a link to a published paper discussing this topic and referred to the information in it as "facts".

  here is my summary of that paper along with comments on it.. one of the opening statements says that:.

  two frequently debated aspects of hominin evolution are the development of upright bipedal stance and reduction in body hair.. so for those who believe this is a stupid topic, it is a subject of interest to many stupid people including the authors of the paper referred to by cofty.

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  shadow

  cofty, I don't have all the answers for everything nor do I portray myself as an authority on every subject. I'd say you are the one who is intellectually dishonest, and egregiously so, in how you answered on the previous topic, picking out one paper and saying that it had the facts to answer the question posted. A question so simple that a schoolchild could answer it.

  Sure there are a lot more examples in support of creation but no doubt you will say none of them have any merit, that you have found all the answers through your extensive study and perhaps point to some other peer-reviewed paper that is full of malarkey.

  Why do you lash out at those who disagree with you about evolution? Do you have some emotional connection to the topic? Perhaps some kind of insecurity that surfaces when you are challenged? A need to convince yourself of your superiority? I don't know and no I don't have a degree in psychology but I do know what I have observed in other topics where rules of common courtesy are tossed out and attacks fly back and forth so much that any possibility of civil discussion is eliminated.
  
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  32

  Evolution Gap - Where's the Fur? Redux

  by shadow in

  1. watchtower
  2. beliefs

  i am posting a second topic on this subject since the first one became overrun by snakes.. cofty posted a link to a published paper discussing this topic and referred to the information in it as "facts".

  here is my summary of that paper along with comments on it.. one of the opening statements says that:.

  two frequently debated aspects of hominin evolution are the development of upright bipedal stance and reduction in body hair.. so for those who believe this is a stupid topic, it is a subject of interest to many stupid people including the authors of the paper referred to by cofty.

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  shadow

  No, creation myths have had all kinds of flights of imagination. However it is not limited to believers in creation. There's plenty of them in the hallowed halls of peer-reviewed journals too.
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  32

  Evolution Gap - Where's the Fur? Redux

  by shadow in

  1. watchtower
  2. beliefs

  i am posting a second topic on this subject since the first one became overrun by snakes.. cofty posted a link to a published paper discussing this topic and referred to the information in it as "facts".

  here is my summary of that paper along with comments on it.. one of the opening statements says that:.

  two frequently debated aspects of hominin evolution are the development of upright bipedal stance and reduction in body hair.. so for those who believe this is a stupid topic, it is a subject of interest to many stupid people including the authors of the paper referred to by cofty.

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• 

  shadow

  I am posting a second topic on this subject since the first one became overrun by snakes.

  Cofty posted a link to a published paper discussing this topic and referred to the information in it as "facts". Here is my summary of that paper along with comments on it.
  

  One of the opening statements says that:
  

  Two frequently debated aspects of hominin evolution are the development of upright bipedal stance and reduction in body hair.

  So for those who believe this is a stupid topic, it is a subject of interest to many stupid people including the authors of the paper referred to by Cofty. This paper proposes a new model for development of these features based on thermoregulation. Their new model assumes a high level of activity which alters the heat balance calculations proposed by previous authors. The graphs appearing below show the predictions of their model for "the amount of heat that must be dissipated by sources other than normal respiration (such as sweating) to maintain heat balance, as a function of time of day". The top graph is for females in the bottom graph for males. As stated in the legend the relatively straight lines the graphs are for hairy or fur covered animals and the two arcing lines are for hairless quadrupeds and bipeds respectively.

  These authors do not come to any conclusions regarding the subject of bipedalism as far as timing or cause stating:

  If both of these changes occurred primarily through thermoregulatory evolutionary pressures, then we predict that hair loss would occur before bipedalism. However, if physical evidence suggests a different relative timing, then this would suggest that the initial evolution of bipedalism was not driven by thermoregulatory selection pressures. . . .

  So currently it appears that upright stance may have evolved earlier than hair loss; however, such a conclusion must be very tentative.

  All their model does is predict that there would be a thermoregulatory advantage near dusk and dawn for highly active hairless creatures that were simultaneously losing their fur and acquiring a greater ability to sweat. These two changes continued to develop in tandem until humans didn't have fur and were extremely good at sweating at which point humans could run around for longer time in hot sunny conditions. This is the "answer" to my question and is referred to by Cofty as "facts".
  
  

  Specifically, we postulate progressive hair loss being selected and this allowing individuals to be active in hot, open environments initially around dusk and dawn without overheating. Then, as our ancestors’ hair loss increased and sweating ability improved over evolutionary time, the fraction of the day when they could remain active in such environments extended. Our model suggests that only when hair loss and sweating ability reach near-modern human levels could hominins have been active in the heat of the day in hot, open environments.

  Dr. Nina Jablonski added that a third factor would have had to occur along with development of fur loss and sweating ability which is not mentioned in this paper. link

  Specifically, we postulate progressive hair loss being selected and this allowing individuals to be active in hot, open environments initially around dusk and dawn without overheating. Then, as our ancestors’ hair loss increased and sweating ability improved over evolutionary time, the fraction of the day when they could remain active in such environments extended. Our model suggests that only when hair loss and sweating ability reach near-modern human levels could hominins have been active in the heat of the day in hot, open environments.

  Dr. Rantala shot holes in this proposed model back in 2007: Rantala

  The cooling device hypothesis
  Perhaps the most commonly held explanation for the evolution of the nakedness in humans is that it evolved as a cooling device (e.g. Morris, 1967; Leakey & Lewin, 1977; Mount, 1979; Ebling, 1985). It has commonly been thought that by abandoning the shady forest, the hunting ape exposed himself to much higher temperatures than those to which he had previously adapted. Thus, it has been assumed that the hunting ape took off his hairy coat to avoid becoming overheated in the hot savannah (Morris, 1967).
  Unfortunately, this hypothesis does not bear closer scrutiny. When we compare the thermal budgets of haired and naked hominids (Wheeler, 1992b), we can easily see that a naked skin is a disadvantage with regard to the circadian integral over both day time (it receives more solar energy, requiring dissipation) and night-time (it requires more endogenous heat production) (Amaral, 1996). Exposure of the naked skin to the air certainly increases the chances of heat loss, but at the same time it also increases heat gain and risks damage from the sun’s rays. Thus, it increases perspiration, leading to dehydration; this in turn may be detrimental in a dry savannah environment. A haired hominid in an open hot environment should actually increase its insulation rather than decrease it. This is precisely the trend followed by savannah monkeys, which have a dense hair-coat and are better insulated than forest primates (Mahoney, 1980).

  Rantala lists twelve different explanations offered by evolutionary scientists for the loss of fur and pokes holes in all of them except for the one he favors. In my opinion it is clear that there is no explanation for this situation and to cite one theory and refer to it as the "facts" is highly disingenuous. In my mind it calls into question all of the topics posted on the subject of evolution.
  

  1. 1. The cooling device hypothesis
     2. The hunting hypothesis
     3. The bipedality hypothesis
     4. The allometry hypothesis
     5. The clothing hypothesis
     6. The vestiary hypothesis
     7. Neoteny hypothesis
     8. Carrion-eating hypothesis
     9. Sex-related hypothesis
     10. Aquatic ape hypothesis
     11. Adaptation-against-ectoparasites hypothesis
     12. Darwin’s hypothesis

  
  One point shared in common by all 12 theories is that humans have no fur due to an evolutionary process. Once creation is ruled out then all sorts of flights of imagination can occur.

  
  
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  87

  Evolution Gap - Where's the Fur?

  by shadow in

  1. watchtower
  2. bible

  evolution paints human ancestors covered with fur.

  fur has several benefits as stated by britannica "the pelts of fur-bearing animals are called true furs when they consist of two elements: a dense undercoat, called ground hair, and longer hairs, extending beyond that layer, called guard hair.

  the principal function of ground hair is to maintain the animal’s body temperature; that of guard hair is to protect the underlying fur and skin and to shed rain or snow.".

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  shadow

  can we stick to fur on this topic?
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  87

  Evolution Gap - Where's the Fur?

  by shadow in

  1. watchtower
  2. bible

  evolution paints human ancestors covered with fur.

  fur has several benefits as stated by britannica "the pelts of fur-bearing animals are called true furs when they consist of two elements: a dense undercoat, called ground hair, and longer hairs, extending beyond that layer, called guard hair.

  the principal function of ground hair is to maintain the animal’s body temperature; that of guard hair is to protect the underlying fur and skin and to shed rain or snow.".

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  shadow

  I'll try to post my critique of this article and whether it merits being called "fact" tomorrow
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  87

  Evolution Gap - Where's the Fur?

  by shadow in

  1. watchtower
  2. bible

  evolution paints human ancestors covered with fur.

  fur has several benefits as stated by britannica "the pelts of fur-bearing animals are called true furs when they consist of two elements: a dense undercoat, called ground hair, and longer hairs, extending beyond that layer, called guard hair.

  the principal function of ground hair is to maintain the animal’s body temperature; that of guard hair is to protect the underlying fur and skin and to shed rain or snow.".

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  shadow

  Ok, I've read the whole thing. Did you actually read the whole thing? You refer to this article as "facts"???
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  87

  Evolution Gap - Where's the Fur?

  by shadow in

  1. watchtower
  2. bible

  evolution paints human ancestors covered with fur.

  fur has several benefits as stated by britannica "the pelts of fur-bearing animals are called true furs when they consist of two elements: a dense undercoat, called ground hair, and longer hairs, extending beyond that layer, called guard hair.

  the principal function of ground hair is to maintain the animal’s body temperature; that of guard hair is to protect the underlying fur and skin and to shed rain or snow.".

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  shadow

  and again . . . . it's not an answer
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  87

  Evolution Gap - Where's the Fur?

  by shadow in

  1. watchtower
  2. bible

  evolution paints human ancestors covered with fur.

  fur has several benefits as stated by britannica "the pelts of fur-bearing animals are called true furs when they consist of two elements: a dense undercoat, called ground hair, and longer hairs, extending beyond that layer, called guard hair.

  the principal function of ground hair is to maintain the animal’s body temperature; that of guard hair is to protect the underlying fur and skin and to shed rain or snow.".

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  shadow

  Yes, I read it. How about we try to keep this cordial?

  Would you be gracious enough to write in layman's terms what the steps were that led to the loss of fur?

  They left the trees and then started walking upright and were better off without fur, at least after they gained enough ability to sweat? Please correct and elaborate