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Ok, so you want AAH. ..
NICHOLLS PHILIP A (pn8886@thor.albany.edu)
Thu, 28 Apr 94 03:01:23 GMT
>> pn8886@thor.albany.edu (NICHOLLS PHILIP A) writes:
> Bryce Harrington writes:
>>Hominid fossils are retrieved largely from areas associated with
>>bodies of water because the water source plays a role in fossilization
>>process. For permineralization of the bone to occur, water must
>>perculate through the soil and pick up mineral salts.
>>Because such bodies of water tend to promote fossilization, isn't it
>>odd that no aquatic apes have turned up in the fossil record?
> Excuse this laymen, but are you sure that people (I mean,
> anthropologist type people) have looked in seaside locations for
> fossils? As far as I understand, there are at least two places which
> the AAT has indicated as good locations to look for fossils. But I
> have heard nothing to indicate that anyone has looked in these areas.
Paleontologists tend to look for fossils in areas that expose
sedimentary rocks. Ancient beaches make excellent fossil localities,
though present day beaches do not.
> Also, I'm not sure about your allegation that fossilization was as
> likely to have occurred. My geologist friend has informed me that
> sea shores are *terrible* places to find fossilization because of
> the constant reworking of the sea bed. The only way they could
> have fossilized would be through massive floods, volcanic
> eruptions, or so forth.
You have to think across time. Where there was a beach today is not
necessarily where there was a beach 4 million years ago. Besides,
the claim is that many of the places where hominid fossils are found
are close to bodies of water. These are, without exception, freshwater
lakes and river beds, not seashores.
> Now, if the apes had been living near lakes and not the ocean,
> things would be different. Also, if they had been living in a salt
> marsh (which is kind of what I think), then fossilization would
> have been more likely.
The claim I was responding to what the suggestion that because
hominid fossils are found near bodies of water that this is somehow
evidence in favor of the aquatic ape hypothesis. As you have pointed
out, Morgan's and Hardy's version of the aquatic ape make use of sea
shore environments. None of the earliest hominid fossils are found
in association with ocean deposits.
> I am not saying that there won't be any fossils to be found; on the
> contrary, I hope there are because if there aren't than there is
> *no* way to convince you that AAH is correct. I'm just saying that
> you cannot use the lack of evidence against a theory when that
> evidence may not have even been preserved or when that evidence may
> be out there but no one is looking in the right locations.
A theory is, by definition, an explanation that has been extensively
tested and has not been disproven. Clearly the AA stuff is not a
theory, which is why I usually change it to AAH. The point is that
we have evidence for a transition from arboreal, forest dwelling ape
to bipedal savannah hominid. We KNOW that transition took place.
> If you want to disprove AAH, the easiest way is simply to find a
> complete series of fossils with no possibility for aquatic behavior
> (for example, all fossils found in savannah areas). The fact that
> the current series of fossils, while in no way complete, have all
> been "savannah" dwellers is the biggest argument against AAH.
This is exactly my point. Lacking fossil evidence, AAH proponents
must go to secondary evidence -- comparative anatomy. It is here
that we get the list of so-called "aquatic" physiology. Now in order
to use comparative anatomy in an evolutionary argument you have to
show that the anatomical evidence you cite is a primitive retention
of an ancestral condition and not a derived trait. If you are going
to argue that a suite of traits emerged in association with a
particular adaptation you have to show that they evolved together.
The aquatic ape supporters do not do this.
>>Hairlessness
>
>Once bipedal, hair loss promotes evaporative cooling.
> True, but in the sun, no hair == more heat absorbsion. And even if
> this is such a good strategy for heat loss, why haven't other
> animals adopted it? (I know this is an over used counter
> argument, but your response is not new...)
Because evolution doesn't work that way. Evolution works with the
anatomy at hand and modifies it. Other animals on the savannah do
not have hind-limb dominance, except for baboons. Baboons have very
few sweat glands while apes, in general, have many. Hominids took
advantage of hind-limb dominance and an abundance of sweat glands.
As a result, humans can not only inhabit the savannah but they can
move around on the savannah when it is too hot for other animals to
do so.
As to heat absorption, the point that Wheeler makes is that bipedal
posture reduces the amount of body surface exposed to the sun. He
has built models and measured this.
>>Increased adipose fat tissue in the breast and thighs of women developing
>> at puberty.
>
>Sexual selection [hint: puberty]
> I don't think so; I think this is an energy store for making
> babies. (Too obvious for you Philip? ;-])
All primates make babies, yet all female primates do not undergo this
change in fat distribution at puberty. There is not biological
reason for a woman to store fat for reproduction until she becomes
pregnant.
>>Floating infants
>Infants tend to drown easily.
True, if you leave a baby face down in a puddle of water they'll
drown. If you throw an inexperienced infant in a pool, panic and
drowning will likely occur. However! It _is_ possible for babies to
float easily in the water.
I don't think that this is a really good argument for the AAH, but it
isn't incorrect.
>> Sheltered nostrils
>
>> Flat faces
> Come on, Philip. Alright, then why the flat face? And I see no
> reason why a flat face implies a need for sheltered nostrils. Your
> assertion may be correct, but I require more of an explanation
> before I accept this.
Our nostrils point down because compared to apes our face is not
prognathic -- it doesn't stick out. Take a look at a mandrill's
nose some time. Mandrill's are a good chose because they have very
long snouts and the nose is set off by coloration on the snout.
>>enlarged complex brain
>
>The fossil record clearly shows that the brain did not enlarge,
>relative to body size, or become significantly more complex until
>Homo habilis. Australopithecus afarensis has a very small brain.
I'll have to agree with Philip here. AAH cannot lay claim to increased
brain size, in spite of how much Morgan might desire it. I think
that the brain size increases were a result of savannah life.
>> Yea let's ignore those pesky details that don't agree with our
>> preconceived notions.
>>
>> Which is exactly what you are doing.
>
> He is not, Philip. I hate how adversarial you can get. Now, I
> know you can make good, scientific arguments, but instead you
> resort to ridicule.
What can I say. That's how I respond to pseudoscience. If there was
any scientific merit to the AAH, I might respond differently. If
there was any hope that good scientific arguments would make any
difference, I might respond differently. In both cases, we know that
this isn't true.
>> I don't disagree with your interpretation of the available evidence.
>> I do, however, strongly disagree with your assertion that it is the
>> only sensible and reasonable interpretation of that evidence.
I do not claim that I evidence is the only sensable or reasonable
explanation. I do claim that the AAH is neither sensible or reasonable
>You have yet to show that your interpretation is either sensible or
>reasonable.
> Look, for some reason you don't accept any arguments, and then you
> imply that they're insensible and unreasonable. Just because they
> don't fit into your world view, just because they might be wrong,
> does not make them insensible or unreasonable.
I have posted specific reasons WHY I don't accept AAH arguments.
They are not wrong because the conflict with my world view They are
wrong because they make no sense and because there are no reasons to
support them.
Aquatic life doesn't explain bipedalism. It's not my world view. If
you are going to argue convergent evolution, which is essentially
what the aquatic ape stuff is, you need an animal that shows a
convergent morphology. Show me a semi-aquatic mammal that has
evolved bipedalism. Why is it that when japanese macaques or
proboscus monkeys enter the water they are not bipeds, even though
the are hindlimb dominant? Show me evidence that bipedalism improves
stablility in the water? Why didn't the aquatic ape undergo
reduction in the thickness of the pelvic bone or limb reduction?
It has nothing to do with my world view. It's just a bad argument.
> I get the feeling that you're just trying to bully the AAH
> discussers away like you did last time.
Yeah, right. I'm bad to the bone.
So tell me, Bryce, what about the AAH do you find so convincing?
--
Philip Nicholls "To ask a question,
Department of Anthropology you must first know
SUNY Albany most of the answer."
pn8886@thor.albany.edu
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