Re: Aquatic Ape: You Asked For It.
5121 Student 09 (cm315c09@nova.umd.edu)
1 May 1994 09:03:52 -0400
NICHOLLS PHILIP A <pn8886@thor.albany.edu> wrote:
>>>> and overwhelmingly massive comparative data for a
>>>> wide variety of other mammals, all showing the transition to
>>>> savannah-adapted forms as the climate altered with the uplift to
>>>> the west and the capture of the Indian Ocean climate between that
>>>> and the growing Himalayan massif. All of that is hard
>>>> evidence, against not a single "aquatic" specimen.
>
>>> That hardly qualifies as *hard* evidence. It does in my book.
>
>> Which is exactly why I must strongly question everything you post.
>
>Paleoclimatological data is hard evidence. Comparative anatomy is
>hard evidence. Fossils are hard evidence.
No matter what you call it, it's still only circumstantial evidence.
If it were hard evidence, we would not be having this conversation.
>Feel free to question anything I say.
Yea, right! Like I need your permission.
>It's only fair since I haven't let you get away with
>anything.
I didn't know I was trying to _get away with anything_. I thought
I was trying to learn more about human origins with other people
with a similar interest. Well, anyway, keep up the good work.
I'd hate to get away with anything.
>If you don't consider this to be hard evidence then a more
>convincing reply would have been an explanation as to WHY you don't
>consider it to be hard evidence.
It is not hard evidence because it is only circumstantial. It
may be very very very very strong circumstantial evidence, but
it is still only circumstantial.
>>Please explain (since it is *so* simple) how the following are
>>savannah adaptations?
>
>>Hairlessness
>
>>> Once bipedal, hair loss promotes evaporative cooling.
>
>> I thought Pete Wheeler explained that water is a much better cooler.
>
>Water is indeed much better at cooling than evaporation. However, you
>maintain that protohominids didn't swim, they just sat in the water,
>cooled off and occasionally caught some fish. If this is the case,
>they why did they lose body hair?
I believe they lost their body hair because they were hot.
>The only aquatic mammals to lose
>body hair are those that are completely aquatic.
What's your point? As far as I know the only >mammals< to lose
body hair are aquatic mammals.
>> Increased adipose fat tissue in the breast and thighs of women
>> developing at puberty. Sexual selection [hint: puberty]
>
>>> Fat chicks float better. [hint: buoyancy]
>So why puberty? Do aquatic apes only need to float when they become
>reproductive? Why the breasts and thighs? Why only females? Don't
>males need to be buoyant also.
These are all very good questions. Can you answer them with
something besides AAT. I think women needed to float more because
they were heavier when they got pregnant.
>Of course, all of this begs the question of whether or not body fat
>increases bouyancy. I don't know of any evidence to support that
>claim. Do you have any?
Wow! I cannot believe this. You need to get out more. Go to the
beach. Put a fat person and a skinny person in the water, see which
one floats better. In fact, the most accurate way to measure fat
content is to first weigh a person on land, then weigh him again
fully submerged in water.
But, if you must have a reference, I'm afraid you'll have to wait
till I unpack all my books.
>>> All body excretions contain salt. The concentration of salt in sweat
>>> and tears is HYPOTONIC relative to blood plasma. That means that
>>> they are not a means of excreting excess salt.
>
>> Who said they were? I just want to know how they are a savannah
>> adaptation.
>
>Morgan originally proposed salty tears as evidence for an aquatic
>past by suggesting they were a means of excreting excess salt. That
>is the basis of my response, which points out they they clearly
>cannot be an excretion.
>
>Why do they have to be a savannah adaptation?
I never said the >have to be< a savannah adaptation. The original
post stated that this was all *so* simple, and implied that even
a simple minded person could understand it. Ok, if it is so
simple how does it explain salty tears or salty excretions in
general? Oh right, I remember.. it doesn't actually explain them
because not everything needs to have an adaptive advantage.
>>>the Diving reflex
>>
>>Identical to "fight-or-flight" reflexes.
>
>The bronchiols in the lungs actually contract when the face comes
>in contact with water. Decreased lung function is *not* fight or flight.
Oops, you missed one.
>>Ventro-ventral mating
>
>>> Also occurs very often in pygmie chimpanzees. Also not a human
>>> universal.
>
>> It also occurs in dolphins, whales, and manatees. What's your point?
>> I want to know how it is a savannah adaptation. Come on guy, this
>> is *so* simple. Remember?
>
>I don't recall anyone claiming it was a savannah adaptation to begin
>with.
Of course not. Anything that can't be explained is just ignored.
Especially if it has anything to do with sex.
> I do recall Morgan claiming it was evidence of a past aquatic
>stage.
Yes, and the reason she made this claim is because the human female
vaginal canal is positioned more forward than our ancestors. A similar
repositioning occurs in all aquatic mammals. This repositioning
makes rear-entry more difficult, thus dolphins, whales, manatees,
and humans mate face to face.
> My point, oh dense one, is that if Morgan's reasoning is
>valid then pygmie chimpanzees evolved from aquatic ancestors
Only if you assume (as only a dense person would) that there
is only *one* possible evolutionary path to each characteristic.
>AND
>those human cultures that do not engage in ventral-ventral copulation
>must have different ape-like ancestors than those that do.
It has nothing to do with culture - it is biology. How modern man
>chooses< to copulate today does not change the fact that his
(and her) equipment is set up ventral-ventral.
Of course, this does not prove AAT. It is just interesting and
I was hoping someone would offer a counter explaination.
>>Floating infants
>
>>> Infants tend to drown easily.
>
>> Only because they are not raised in an aquatic environment. Infants
>> in such an environment can swim *before* they can walk.
>> Babies can and do float. This is an indisputable fact. I've seen
>> it with my own eyes. How is this a savannah adaptation. *so* simple.
>
>I dispute this fact. Provide scientific evidence to support it.
>Please not that I am not disputing the possiblity that infants can
>learn to float. I am disputing that they will do so without the
>assistance of an adult.
How do you teach a baby to float? Put them in the water, they float.
If they don't you're out of luck.
But, I agree. I would also like to see scientific evidence.
I'll look it up.
>>Sheltered nostrils
>
>>> Flat faces
>
>> Oh, of course, flat faces ... savannah, an immediate connection there.
>
>I am providing explanations for each item you list. They are not all
>necessarily savannah adaptations.
Well, then perhaps you should read a bit more closely. This list
starts out with the following statement:
Please explain (since it is *so* simple) how the following are
savannah adaptations.
>What I am trying to show is that
>they are definitely not aquatic adaptations.
^^^^^^^^^^
And you're doing this by pointing out that man has a flat face?
Sorry, but it begs the quesion - why does man have a flat face?
>It is a fact that the
>human face has become flattened during the course of evolution and
>that the shape of the human nose reflects changes that have occurred
>in mid-facial morphology during hominid evolution.
Great. So what?
>>head hair with rest of body hairless
>
>>> Bipedalism reduces the amount of body surface exposed to the sun.
>>> The one area of the body for which this is not true is the top
>>> of the head.
>
>> Very good. To bad the same can be said for cooling off in the
>> nearest pond. Head is exposed, must remain covered. Body is
>> cool, no need for hair.
>
>The difference between the two is that the one I offer is supported
>by experimental data collected by Pete Wheeler and is consistant with
>evolutionary theory, namely that the loss of hair promotes better
>evaporative cooling.
>
>Your statement is conjecture on your part and invokes a neo-Lamarkian
>explanation to explain hair loss. Evolution doesn't follow Lamarkian
>"use it or lose it" logic.
I never suggested any such thing. I claim that man lost his body
hair because he was hot. This is supported by experimental data
collected by Pete Wheeler and is consistant with evolutionary
theory, namely that the loss of hair promotes better evaporative
cooling.
>>Upright stance
>>
>>>[1] Reduction of heat stress.
>>>[2] Increases range of visual field
>>>[3] Hands are free to gather and carry foods.
>>>[4] Primates that are suspensory feeder tend to be
>> bipeds when they have to be terrestrial.
>>>[5] Bipedalism is more efficient energetically than
>> primate-style quadrupedal locomotion when covering long distances.
>
>> I agree. Unfortunatly, this seems to be the basis for the
>> entire savannah theory (oh sorry, I forgot you mentioned before
>> that there is not "savannah theory").
>
>There is no savannah theory. There are numerous hypotheses about the
>origins of bipedalism and most of them involve the savannah. One of
>them, however (suspensory feeding) does not.
>
>Each of the above is based on observed primate behaviors. In
>otherwords, evolution tends to work with what is on hand in terms of
>behavior as well as morphology. Bipedalism is part of the behavioral
>repetiore of most anthropoid primates. Aquatic behavior is not.
To coin a phrase, _hogwash_. You yourself pointed out that other
apes swim and dive. This is well documented.
>>>find hand-grasping ability
>>
>>Retention of primitive primate condition. Fine motor skills are
>>associated with manipulation.
>
>> Well, good. I'm sure that could only be used on the savannah.
>> Wow, it's all so simple.
>
>Once again, no one is claiming that this is a savannah adaptation.
>As a matter of fact, this is specifically an arboreal adaptation. It
>is not an aquatic adaptation.
Agreed. Good point.
>>>communication through calls rather than badges or pheromones
>>
>>In general, this is the rule for anthropoid primates
>
>I've never heard this. Can you back it up with a reference please?
>
>Primate Behavior, by Allison Jolly.
>The Antecedents of Man W. LeGros Clark
>
>Primates show a reduction in the size of the olfactory lobe of the
>brain relative to other mammals.
Thank you. I'll look them up immediately. :-)
>>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 feel like I'm on Jeopardy. What question goes with this answer?
>
>The point is that since the earliest hominids did not have large
>brains, and since the aquatic ape lived before these established
>hominids the aquatic ape could not have had a large brain. It's so
>easy, really it is.
The fact that the aquatic ape could not have had a large brain does
not mean the aquatic ape could not have existed.
>> feet not grasping
>
>>> Toe placement stablizes stance for bipedal locomotion.
>
>> Of course we all know human ancestors would never stand in water.
>> This is something they would just never, never do. Bad, ape,
>> stay away from that water, or else.
>
>Suppose they did. Since water supports most of the body weight, why
>do they need to move the big toe inward. This only makes sense for a
>terrestrial biped.
Because they were not completely aquatic. Meaning they also spent
time on land.
>The only way for any of the above to make sense is to ignore some
>very basic facts of biology.
You mean facts of biology like this one: fat floats.
>You don't understand evolution, you
>don't understand what paleontologists have to say about the human
>fossil record
I understand them well enough to know they have not determined
how man evolved to be fat, hairless, and bipedal. If they had
we would not be having this discussion.
>and you don't understand Morgan's or Hardy's positions
>regarding the aquatic ape.
I understand it quite well, and I disagree with most of it.
I also disagree with most of what I've heard of the savannah
theory. Which is why I decided to create one for my own use.
>We are not talking about "man" here (or woman, for that matter). We
>are talking about something that had just diverged from the common
>ancestor we share with the modern great apes but which was not yet a
>full hominid -- i.e., it had not achieved bipedal gait. The only
>thing we KNOW is that hominids made the transition to bipedalism.
>
>You want protohominids to get a drink of water? Fine, no problem.
>All primates do this. You want them to jump INTO the water to cool
>off, well, now you have problems. Only two primates do this on a
>regular basis and both of them are monkeys. Still, I'll give you
>this one.
>
>What does that explain?
>
>Does it explain the one transition we know occurred at this specific
>time? No, it does not. In water most of the bodies weight is
>supported by water. There is no advantage to the various
>re-arangements of muscle and bone associated with bipedalism -- all
>of which are changes that are associated with distribution of weight.
I believe man spent some time in the water - not that he >never<
left the water. The fact that man developed weight bearing
feet does not disprove that he spent some time in the water.
David Greene
cm315c09@nova.umd.edu
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