Re: Aquatic ape theory
H. M. Hubey (hubey@pegasus.montclair.edu)
9 Oct 1995 00:42:25 -0400
ronkanen@cc.Helsinki.FI (Osmo Ronkanen) writes:
>What my point is that whether a human being has hair is hardly
>irrelevant for the survival. That means it is either beneficial or
>harmful. If the hair is beneficial, then I see no reason why human
>beings should not have developed the hair back in the millions of years
>since the aquatic life. That strongly implies that the lack oaf hair is
>beneficial in the land life. If it is beneficial one needs no aquatic
The point is that your argument makes hair and aquatic life equivalent
because you say that since I said A => H' (Aquatic => No_Hair), that
it must also be true that A' => H (Non_aquatic => Hair). There's
no reason why the second should be true if the first is true.
If the fur makes heat conduction difficult then if the hair was
lost as a side effect of increasing heat conduction, then it
doesn't follow that hair would have to return since by that time
perhaps they were in a position to cover themselves to decrease
heat conduction in the cold. Or perhaps they could have slept
out in the cold (not too cold obviously) and that their
metabolism would have been higher than if they used blankets.
>Maybe the hairlessness developed because of increased energy need
>because of increased brain size, increased activity because of
>hunting, increased intake of energy because of meat eating and
>lowered surface/mass ration because increase in size humans needed
>better method of regulating body temperature.
WEll for large animals like elephants and rhinos the argument is
that since they have greater mass for their surface area, they'd
have to be naked since otherwise they could not expel heat fast
enough and would die of overheating. Meanwhile the same argument
is used to explain why the elephants seek water in hot weather
since it helps them cool down. Well, let's look backwards. If they
were using the same trick (i.e. dunking in water) a long time
ago, then they wouldn't have to lose their hair or it could
be exactly because they spent so much time in the water that
they started to lose their fur. So then it's a roundabout way
of saying that it was their aquatic lifestyle, after all, that
made them lose their fur.
>>>The fact is that we cannot ignore the most recent 5 or so million years
>>>in evolution when one considers something as fundamental as body hair.
I don't know when it happened. It could have been happening all
along and I'm not sure one way or the other when it would have
started or when it should have ended or how long it would take
to lose most of it.
That doesn't mean that I don't believe some kind of an aquatic
stage was involved in the loss of fur and causing the changes
in the skeleton.
--
Regards, Mark
http://www.smns.montclair.edu/~hubey
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