Re: Why is Homo sapiens hairless?

Paul Crowley (Paul@crowleyp.demon.co.uk)
Sun, 17 Nov 96 12:05:22 GMT

In article <01bbd1c4$364f9140$LocalHost@dan-pc>
rohinton@collins.prestel.co.uk "Rohinton Collins" writes:

> Hair insulates the body. It protects the body from solar radiation, but
> also prevents efficient heat loss - this is why you will never see a
> savannah baboon out in the midday sun.

Only mad dogs and Englishmen . . . Are you seriously suggesting that
Lucy & Co hunted in the midday sun?

> > and then there's the
> > cold at night, the thorns, the poison ivy . . .
>
> How about shelter and perhaps, god forbid, clothing?

Susan was talking about "once this bipedal ape . . ", IOW close to
speciation, when shelter and clothing were far, far in the future.

> > And why should the need for heat loss be so compelling?
>
> Perhaps this was our ancestors' reason for hair loss. In order that they
> may brave the midday sun in order to hunt/forage/scavenge whilst its furry
> cousins were forced to seek shelter.

C'mon, we're talking about a 3.5 feet high animal, short legs, big
feet, etc., . . . . Hunt? Forage in the midday sun? Scavenge in
the midday sun? Scavenge for what? Kills are at night.

Oh alright. The whole thing is a 'just-so' story. Nothing is based on
the evidence we have to hand, be it archaeological or morphological.
In fact it's directly opposed to all of it. It's a shame I've wasted
time reading about it. Scavenging? Ha!

> > What was waddling little Lucy doing that needed such energy?
>
> Can you please dispense with the incredibly subjective and misleading word
> 'waddling' Paul? A. afarensis was a fully adapted biped. There is no reason
> to assume that her locomotion was markedly less efficient than ours just
> because it was different.

Yes, there is. What Olympic event would you want to enter Lucy for?
Marathon? 5,000 metres? 100 metres? Long jump? High Jump? She
was a "fully adapted biped" alright. But adapted to what? Condors
and humming birds are both "fully adapted to flight", but the
differences matter. You cannnot wave them away with some idle
generalisation. Please tell us what was Lucy good at.

> > Why do babies have virtually none at all?
>
> Babies, children and women have just as much body hair as men. It's just
> that their hair is very fine, almost to be invisible.

That's great to know. So the naked emperor wasn't naked after all.
The little boy was wrong. He was lacking a B.Sc in Anatomy.

> > What relationship does its loss have to sweating?
>
> This has been explained many times Paul, do we have to go over old ground?
> It is very simple: Less hair means more air movement next to the skin.

I was really asking the question in a temporal sense. Must
sweating have developed at the same time as hair loss? You indicate
it did, and that both were tied to bipedalism and the initial
speciation. That's how I see them too; but I'd like a more
thorough analysis.

> Oh alright. The whole thing is a 'just-so' story. Nothing is based on the
> evidence we have to hand, be it archaeological or morphological. It's just
> as well I haven't wasted any time reading any books on the AAT. From what I
> have read in this newsgroup, and from published papers, it is complete and
> utter nonsense. Shellfish? Ha!

We have uncontrovertible evidence that our ancestors (and other
hominid lines) were consuming a certain food in quantity at around
150 Kyr. But let's ignore it. Only a tiny fraction of such sites
are available for inspection. But let's forget that. All hominids
since 5 mya have been readily capable of exploiting such resources
and manifestly incapable of much else. But that's of no consequence.
Such food provides the proteins that were essential for the brain
development we know took place. No matter. Such food is next
to impossible to obtain elsewhere. Yawn. We have no significant
evidence of any other diet. Hey George, mine's a double whiskey.
All hominid dentition (otherwise inexplicable) is readily explained
by adaptations to this diet. Who is this bore? All fossil
evidence ties in with it. Zzzzzzz . . . . .

We know what we think. Our Victorian forebears had the right ideas
about human evolution: essentially that all our ancestors hunted on
the savanna. They wrote this down in books and the professors
passed it to students who became professors who passed it on to
students who became . . . . And now we're getting nice and
comfortable . . Zzzzzzz . . .

Paul.