Re: Polar Bear Challenge for AAH opponents
Kevyn Loren Winkless (firstname.lastname@example.org)
17 Dec 1994 20:53:22 GMT
In <email@example.com> firstname.lastname@example.org (Pat Dooley) writes:
>In article <1994Dec14.email@example.com>,
>firstname.lastname@example.org (Phillip Bigelow) writes:
>>All of the aquatic ape supporters on this dissussion group have
>>stated that there may be no structural changes in the hominid skeleton
>>to aquatic lifestyle. If so, no conclusion can be reached.
>Absolutely amazing. We have been saying wading/bipedalism/proboscis
>monkey/Lucy/Macaque monkeys/major structural change/ etc. etc. and
>this Phillip caught none of it. Beyond belief. Totally beyond description.
>Is this guy for real? Has he read nothing? Or anything?
It has been repeatedly stated in this group as a defense for the _lack_
of fossilized structural evidence for aquaticness that there need not be
any structural evidence which would have survived the process of
fossilization. Or haven't you been following this thread?
The fact remains that _modern_ examples of semi-aquatic apes are _not_
evidence that one of our ancestors was semi-aquatic. It merely points
out that it is not impossible that this was so.
Without structural evidence (and I have yet to see any which was not
merely conjecture based on analogy) _there_is_no_way_ to verify or debunk
the hypothesis. I am still trying to scare up some more literature, so I
don't know the details of the assertions made by AAT, but if there is no
way to verify the hypothesis, it can be considered no more than
metaphysical nonsense, and thus empty speculation...similar to
speculation regarding possible tool use in dinosaurs. We can't verify
_or_ disprove it, and until we can do one or the other we're wasting our
It has been suggested that the only way to support the hypothesis would
be to discover fossil hominids in an appropriate context - but this has
been refuted sufficiently, I think, for us to say that while it would be
suggestive it would not be sufficient in and of itself.
Are AAT proponents able to suggest:
a) probable _physical_ evidence to support aquaticness
b) a probable region in which such evidence will be found?
If so, get funding (rob your piggy bank if need be), go there, and look
for your evidence. If you find it, good. If not, well...
>If an ape goes into the water it is more likely to do it on 2 legs than 4.
>Of the primates observed doing this in the wild the score is :
>2 legs: 2; 4 legs: nil.
>If environmental conditions make an ape do it often enough, it will
>get better at it. It might take a few million years of evolution to
>achieve proficiency, but it'll happen, or the ape will go extinct.
Yes, _but_ it has also been pointed out that these primates go bipedal
_only_ when they are unable to go further quadripedally without
drowning...if the aquatic ancestor were comparable to these primates,
why was not quadripedality retained, as it was in the primates you so
fondly hold up as examples? And if our aquatic ancestor was more
aquatic, there is still no evidence that this would force bipedalism;
look at otters. They are fresh water semi-aquatic mammals which feed on
fish and shellfish (I am given to understand that this is the diet
proposed for AA?) and they are _not_ bipedal. Instead they have
developed quadripedal swimming.
>The evolution of bipedalism required major skeletal adjustments.
>According to Richard Leakey and Roger Lewin (who studiously ignore
>the AAT), "the evolutionary shift from quadrupedalism to bipedalism
>would have required an extensive remodelling of the ape's bone
>and muscle architecture and of the overall proportion in the lower
>half of the body. Mechanisms of gait are different, mechanics of
>balance are different, functions of major muscles are different.
>An entire functional complex had to be transformed for efficient
>bipedalism to be possible." cf. "Origins Reconsidered".
I agree that bipedalism requires huge architectural changes, and as such
represents a huge investment in specialization...but despite the fact
that humans have long relied heavily on shellfish and other aquatic food
sources, there is no evidence that bipedalism evolved specifically for
aquatic purposes. Plenty of plains-dwelling animals are bipedal:
groundsquirrels and other rodents for one example, and many birds have
become bipedal to the extreme to deal with long grasses etc (although
they were bipedal to start with, and so had presure to retain the
structure). Wading animals are appropriate analogous evidence for
pressures toward bipedalism, but savanna/prairie animals are not? You
see the dangers of speculating on the basis of analogy.
>The AAH people ask: under what evolutionary conditions could this occur
>without breaking the principle of non-disadvantageous intermediates?
>And answer came there nothing but a bunch of convoluted theories that
I agree that the entire question of bipedalism etc. demands further
study...it is clear that we don't understand everything, and that there
are huge gaps in our knowledge of our own history which might lead to
AAT might very well be true, and even if not it might be a useful concept.
_but_ we need a great deal more substantial information before that will
be the case. Analogy is fine to flesh out an already well substantiated
hypothesis, but it is not proof. Give us something more.
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