Re: Why is Homo sapiens hairless?
Rohinton Collins (rohinton@collins.prestel.co.uk)
30 Oct 1996 21:19:40 GMT
John Waters <jdwaters@dircon.co.uk> wrote in article
<01bbc5e8$521c6de0$472670c2@default>...
[snip]
> Consider the Helpless Baby Theory. It really is simple,
> (and
> arguably logical). Human babies are helpless for a much
> longer
> time after birth than ape babies. Fact.
Granted.
> When the hominid
> babies
> started to become helpless for longer periods after birth,
> their
> mothers had to carry them in their arms. (As now.) Fact.
Not a fact, but a logical assumption.
> When a baby is carried in its mothers arms, there is a
> change in
> its effective surface to mass ratio. Fact.
Relative to what? To the baby floating in mid air? Certainly not to a baby
lying on the floor.
> This is because
> 20
> percent of the babys skin
Skin? Wouldn't that have been fur?
> is in direct contact with the
> mother.
> This causes the babys core body temperature to rise. If
Ever heard of thermoregulation? Anyway, the fur would insulate the baby.
> the
> core temperature continues to rise the baby could die of
> heat-stroke. Fact.
Fact? Again, ever heard of thermoregulation?
> This creates evolutionary pressure to reduce the dangers of
> infantile overheating. This leads to the moulting of the
> fetal hair
> in hominid infants. Fact.
What do you mean fact? What fact? This is supposition. Fur insulates, it
does not cause overheating. That's some leap in logic there John. Sure you
weren't a creationist in a past life?
> It also leads to the development
> of
> subcutaneous fat in the female, where the fat is
What?
> concentrated in
> the areas of the female body which come into direct contact
> with
> the infant, when it is carried by its mother. Fact.
What 'areas' of the female body' ? Again, fact? As far as I was aware, the
only areas where *extra* or *additional* subcutaneous fat is laid down in
female humans is on the hips, bottom and thigh.
> The mothers subcutaneous fat insulates the baby from the
> mothers own internal body heat. Fact.
Did you forget about the fur? Anyway, the body temperatures would be the
same, so this is meaningless.
> The subcutaneous fat of the female leads to evolutionary
> pressure for less body hair in the female. This is the
> present
> situation. Fact.
Just quit saying 'fact' will you? There is absolutely no flow of logic in
your last statement.
> In Chimpanzee and Gorilla species, the juveniles stay with
> their
> mother and share her nest until adolescence. After
> maturity, the
> young males are driven out by the alpha male. Fact.
Untrue. Chimpanzees enjoy a multi-male polygynous social structure where
the males are related to each other. It is the females who are unrelated.
It is the young females who migrate to other groups or are kidnapped by
raiding males from other groups. (This *fact* thing is becoming REALLY
tiresome.)
> If this pattern of behaviour was also true of hominids, the
> young
> males would need body hair after puberty. And this is what
> happens. Fact.
Oh god, oh god. Each of the extant hominoids enjoy a different social
arrangement with respect to males and females. Do not try to infer hominid
social structures by using them as a model. <- Major error.
> Simple
Not
> parsimonious
Absolutely not
> logical
You what?
> and reasonable.
Not at all
> The only real
> problem with the Helpless Baby Theory is that it is based
> upon the facts.
>
> John.
>
John, with respect, if you reply, drop the *fact* style of writing. It is
annoying. I counted only one true fact in your theory, the first. The rest
were either assumptions, inferences, or downright leaps of faith. Re ape
social structures: DO SOME READING. How can you say it is more parsimonious
than my theory? Do you understand what the word means? If not, then look it
up.
Regards,
Roh
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