[extropy-chat] Re: evolution again

[Spike]

> stencil
> Subject: [extropy-chat] Re: evolution again
> 
> 
> Spike  wrote


> > [ ... ]  humans evolved
> >in a tropical climate, but some humans left the tropics for colder,
> >harsher climates, which required them to wrap themselves in the skins
> >of the beasts they slew...

stencil:
> ...leaving the better-displayed tropical population to enjoy 
> informed choice of better-endowed mates,  while the colder faction had
to let 
> other factors affect choice,  it still smacks of Lysenkoism to see a
cause-effect
> relationship here.   Why didn't we just grow thicker body hair?  Why
do New
> World,  Siberian, and Inuit populations - who all have been filtered
by cold
> environments - have such sparse pelts, compared, say with West Asians?

Good question.  This notion of two ratios, one for 
survival cost to benefit and the other for attractiveness
cost to benefit works great to explain what would
otherwise be a most puzzling observation.  The
survival cost to benefit of hairlessness in a
cold climate is surely greater than 1, that is 
Rs(-h) > 1, however if these populations for some 
odd reason decided hairlessness is attractive, 
Ra(-h) < 1, then the product of Rs(-h) * Ra(-h) 
could equal 1.

Thanks Stencil!  Great example of what I was trying
to express.  We need not go to great lengths trying
to explain *why* Eskimos and Inuits would find 
hairlessness attractive, for human tastes in fashion
are truely weird.  Take tattoos, for instance.  Please,
take them.  Away from me.  And body piercing, and 
teenagers with the droopy pants, what the hellll is 
THAT about?  But evidently the young and fertile find
that stuff appealing.  This I cannot explain.

Nowthen, I may be trying too hard with this example.
If the cold-climate people did wrap themselves in
animal skins, *their own* body fur becomes irrelevant.

Perhaps as in the example of the penis, the north-
wandering people *did* develop some greater amounts
of body fur than their stay-at-home cousins: the
survival cost to benefit ratio of hairlessness
was high enough that the product of Rs*Ra was
greater than 1, so hairy-ness increased.  Then
the protohumans figured out how to clothe themselves 
in animal skins, then suddenly survival disadvantage of 
hairlessness suddenly was supressed, Re(-h) of hairlessness
(the product Rs*Ra) suddenly shifted to greater than 1,
so hairlessness became the *in* thing with the northern
proto-people as the Re(-h) settles back to an
equilibrium value of 1.

If anything, the notion of Ra and Rs might actually
*overexplain* hairlessness in eskimos and that
other observation mentioned in a previous post.
Perhaps Ra(-h)<1 for humans in general, which is
to say that the attractiveness benefit of hairlessness
was persistently greater than its cost, which is
perhaps what caused humans to develop towards being
less hairy in the first place, before the migration
out of the tropics.

> ...the very ease with which counter-survival traits can be found
serves as a caution 
> light...

On the contrary, the notion of Re helps to explain
the ease with which counter-survival traits can
be found.  Perhaps I misunderstand your objection.
Re explains *why* we should *expect* the apparently
counter-survival traits that we have, and that are
easily spotted in many species, such as the heavy and
attention-attracting tail plumage of the peacock.

spike