Freethought & Rationalism Archive

pz · 09-12-2002, 08:16 AM

Quote:

Originally posted by Vorkosigan:
The theory is trash and has been known to be trash.

Exactly. The AAT is facile codswallop.

I've argued in the past with wet ape proponents, and there are many other strikes against their ideas. One of the biggest is the endless inconsistencies. They argue that subq fat/hairlessness are adaptations seen in other swimmers, like dolphins; so in that comparison, they are claiming our ancestors were fully aquatic, spending so much time swimming that we were selected for streamlining. Marc Verhaegen has even claimed that the shape of our nose is optimized for cutting through the water, while minimizing pressure on the nostrils while engaged in rapid, head-forward motion! Yet at the same time, they will backpedal and say that they're only claiming that our aquatic ancestors were frequent waders, in order to explain our long hindlimbs.

I've even had AATers claim that the pelvic anatomy of otters, humans, and dolphins shows a clear progression, where humans are intermediate in form between the otters and the dolphins, to support the idea that we are adapted for that lifestyle. A moment's glance at the pelvic bones of those three, though, shows that humans are really the odd man out, with a shift in pelvic orientation that completely contradicts their claim.

seanie · 09-12-2002, 08:19 AM

Quote:

These people are rather short and all but round in apperance

Well they weren't short but I've seen plenty of spherical Americans.

pz · 09-12-2002, 08:25 AM

Quote:

Originally posted by seanie:


Well they weren't short but I've seen plenty of spherical Americans.

They should all go swimming!

Wyz_sub10 · 09-12-2002, 09:10 AM

Quote:

Originally posted by seanie:
Criticising the theory because were not 'ideally' suited to an aquatic environment hardly seems fair.

Surely the argument is that we evolved in a way that was 'better' suited to the environment.

I wasn't sure who this was directed at, but I think my points suggested that we are not better suited for an aquatic environment.

"Ideal" is a bit meaningless. I don't think (and I doubt anyone does) that we are "ideally" suited for anything that we haven't specifically designed. (cart>horse)

KC · 09-12-2002, 10:12 AM

From what I've seen of AAT, it is a case of hyperadaptationism, where every trait, no matter how insignificant must have positive adaptive value, and thus requires an evolutionary just-so story to explain it.

Cheers,

KC

atrahasis · 09-13-2002, 01:05 AM

hey guys,

Quote:

Originally posted by Peez:
Define "mystery".

<a href="http://www.dictionary.com/search?q=mystery" target="_blank">Click here to find out</a>

Quote:

This sounds suspiciously like the same sort of argument that a creationist might make.

What makes you think that only creationist can make such an argument..I'm not one and i just made one.. Or you want the defination of bizarre too <a href="http://www.dictionary.com/search?q=bizarre" target="_blank">Click here to find out</a>.

Quote:

So is the sudden creation of the universe about 6,000 years ago (with the appearance of much greater age, by some perverse god or gods).

AAT does not suggest that man was created by gods but rather presents the theory that at some time between 6 and 9 million years ago the ancestors of human beings returned to a marine existence, thus accounting for homo sapiens' major differences from other apes.

Quote:

Sorry if I sound a bit dismissive, I have seen this brought up a number of times

Sorry if I sound a bit dismissive, I have also seen this brought up a number of times

Quote:

Bzzzt! Sorry, but humans are apes.

How right you are!!!

Quote:

Again, humans ARE apes.

The first one is enough!!

Quote:

LOL! Humans living in hunter-gatherer societies were not as fat as we are today, and in any event stored fat is energy-rich (so carrying it is hardly a disadvantage, until you have a huge amount). Plus: is the author suggesting that aquatic humans had their fat carried by the water? To be in deep enough for that, they would not be standing on their bipedal frame. They could try to swim, but then why are they bipedal? By the way, the distribution of fat does not streamline us (compare a fat human with s seal).

You win on the fat issue...But sir what about speech..Come up with something to explain this too..

Quote:

Perhaps you should ask the AAT people why we get water in our nose and ears when we swim. How about asking why we have such prominant external ears. Why do our nose holes point down? Why do we loose heat so quickly in water (despite that fat layer)? Why is there not a single aquatic mammal that looks even remotely like us? The AAT is a cute idea, fun to think about, but quite naive. It does not merrit serious scientific attention.

Look at this

You can also try swimming/diving tell someone to take you a photo and tell us what you see

Let the wise teach the mystery to the wise

--Thanks--

[ September 13, 2002: Message edited by: Black Moses ]

atrahasis · 09-13-2002, 01:37 AM

oops! Flood

[ September 13, 2002: Message edited by: Black Moses ]

atrahasis · 09-13-2002, 01:38 AM

Since it seems most you guys never even bothered look at the links i provided on my first post, i don't mind bringing the service 'closer' to the people::

Quote:

We are the Chimpanzees' closest relative in the animal kingdom. Only an estimated 1.4% of
our DNA is different from theirs. Even gorillas are further from chimpanzees than we are. We
are closer to chimpanzees than zebras are to horses, and yet just look at us...
Clearly something dramatic happened to us since the ape/homo split around 5.5 million years
ago.
Chimps are hairy (just like all but one of the other 200 or so types of primate.)
Chimps are terrified of water and are very poor swimmers.
Chimp babies are born very skinny with no excess fat to carry around with them.
Humans are naked (the only type of primate that is)
With a little help babies learn to swim excellently and can grow up into superb skin-divers.
Human babies are born very plump and have a thick layer of fat under their skin.
Zoologists tell us that the only two types of animal that tend to have lost their pelts are

aquatic/semi-aquatic ones like dolphins and hippopotamuses and subterranean ones, like

certain kinds of moles.

The simplest explanation for our superior swimming & diving ability (compared to

chimpanzees) is that since the ape/homo split, the ancestors of human beings lived in an

environment where natural selection favoured that ability.
Isn't it rather obvious that our ancestors lived in a more aquatic environment than we have
been led to believe?
Several enigmatic features found in Homo, while unique among primates, find close parallels
in the physiology of certain aquatic or semi-aquatic mammals. Examples include 'nakedness'
(loss of functional body hair), a layer of fat bonded to the skin, a descended larynx, and
voluntary breath control - an essential precursor of speech.
Walking on two legs has no mammalian parallel, but Hardy noted that a wading ape venturing
into deeper water would simply have to walk upright to breathe!
My critics said AAT was unnecessary. They claimed that the scenario for the ape/hominid
split was well understood: one population of the ancestral apes moved from forest out into
the "hot, dry savanna". There, they became two-legged so as to "run faster" and carry
weapons, while the torrid heat caused them to sweat profusely and shed their body hair. AAT
referred to all this as "the savanna theory". In different versions, it reigned supreme for
over fifty years.
In what for me has been a remarkable and exciting development, the experts have in recent
months suddenly started to abandon this whole idea. Detailed studies of the African
paleoenvironment show that savanna conditions evolved in Africa much later than had
previously been imagined. The habitat of Lucy (Australopithecus afarensis) is now agreed to
have been "lush and well watered" (her bones lay among crocodile and turtle eggs and crab
claws).
Australopithecus ramidus, a million years earlier still, lived in woodland. Richard Leakey
wrote in 1992: "The great plains and the immense herds on them are... much more recent than
the origin of the human family". And now Professor Phillip Tobias, lecturing in London on
his recent fossil discovery "Little Foot", has announced that "the savanna hypothesis" (of
which he had been one of the most illustrious supporters) "is washed out".
Is this the beginnings of a paradigm shift completely revolutionising our understanding of
human origins? I think it could be. The strength of savanna theory lay in its contention
that the hominids' habitat was radically different from that of the apes. This claim is
severely undermined if the protohominids were largely tree-dwelling, as is now agreed, only
crossing open spaces in occasional transit from one patch of forest to the next.
Meanwhile, AAT is waiting in the wings. The arguments against it look increasingly
precarious. Nearly all the Rift Valley fossils were recovered from lake or river sediments.
Unfortunately, this can never prove that the entire species lived by the water, since only
bones deposited in watery sediments get preserved. On the other hand, neither can it
disprove the idea. If the first hominids were indeed largely tree-dwelling, why did they and
no other apes become bipedal on the ground? A flooded forest offers a possible answer: there
is geological evidence of extensive flooding in the areas where the oldest hominids are found.
The strongest argument for AAT is the number and variety of Homo's unique features, for some
of which the aquatic explanation is the only one on offer. These anomalies are not a common
subject of research. Many specialists still find them simply distracting, and sometimes
respond "We may never know the reason" or even "There may not be a reason".
But the questions will not go away. Professor Tobias enjoys being back at square one. "A

change of paradigm", he says, "shakes us up; it rejuvenates us; and this above all, it

prevents mental fossilisation - and that is good for all of us".

Quote:

Biochemical/Dietary Evidence
Another body of workers who are advocates of a more aquatic past for our ancestors than the
prevailing view are those biochemists and dieticians who are convinced that the modern human
need for certain essential fatty acids (EFA), especially in brain growth is evidence that
hominids must have evolved in places rich in those substances. Two that seem to be
particularly important, Docosahexanoic Acid (DHA) and Arachidonic Acid (AA), are found most
commonly in aquatic foods.

Those interested ca look at this::

<a href="http://www.wf.carleton.ca/Museum/aquatic/cont.htm" target="_blank">The Role of Water in Human Evolution </a>

<a href="http://www.riverapes.com/Me/Work/BipedalismThesis.htm" target="_blank">Bipedal Wading in Hominoidae past and present By Algis Kuliukas B.Sc.</a>

Let the wise teach the mystery to the wise

[ September 13, 2002: Message edited by: Black Moses ]

Stephen T-B · 09-13-2002, 02:16 AM

Dear Wyz - I assure you I haven�t a better handle on this simply because I spoke to Morgan, but I think the Savannah scenario has insufficiencies.
Vorkosigan evoked kangeroos in his post as an example of a savannah animal that adopted bi-pedalism but even in my ignorance I can tell that there is a difference between what they do and what humans do. They have very large back legs, I seem to remember, which enables them to leap along at about 30mph.
So they overcame ther inherent disadvantages of bi-pedalism in terms of speed by developing extremely powerful hind limbs. The only animals we can outrun, of any decent size, are sloths and I don�t think there were a lot of those to catch and eat on the savannah.
Vorkosigan also mentioned hippos, elephants and rhinos as being hairless. I didn�t think the hippo was a savannah animal. I thought it spent most of its time in the water. And is it known that the distant relatives of the elephant and rhino were not water-loving creatures? Morgan thinks they were.
The cartiliginous shield which protects our nostrils is a very strange structure. What advantage might it have had on the savannah? We can see quite clearly that when a human swims, it protects the nasal passages from an ingress of water. On the savannah, did it keep the dust out? Not very well, or perhaps humans would be less prone to hay fever.
Duvenoy wrote: �Bi-pedal locomotion is indeed handy for sloshing around in the shallows, but it is also highly advantagous in the predator populated, high grasses of the African savannahs.�
OK, so why don�t baboons walk around on their hind legs? Why doesn�t anything on the savannah walk around on its hind legs, apart from the kangeroo? And if height were a real advantage, humans didn�t do particularly well at acheiving it. Presumably height would have had a survival advantage: taller specimens would have survived better and bred more successfully and humans would have got really tall. But how tall were our early ancestors?
I sense closed minds here. The Aquatic Ape suggestion (calling it a theory, and thus elevating it to the status of a proper scientific theory is clearly wrong) could, I suggest, get us thinking more constructively and creatively than has hitherto been in evidence.
And why, I wonder, such passionate insistence on the savannah suggestion? What is it about the savannah that makes scientists think it answers all the questions provoked by the features which so clearly distinguish us from any other mammal (and which, I might mention, allowed those Middle Eastern Bronze Age sheepherders to think we were gods, not animals.)

seanie · 09-13-2002, 02:40 AM

I'm not holding a torch for AAT but some of the criticisms seem unfair to me. Some of it seems to be along the lines of 'well that's not an adaptation for an aquatic environment because such and such an aquatic mammal doesn't have it and they're much better suited.'

But that doesn't seem a fair comparison.

The only valid comparison is whether any supposed adaptation would've been better for an aquatic environment in comparison to the common ancestor of us and chimps. And it doesn't have to be a staggering improvement just better.

Fat may be a crappy insulator (certainly compared to foamed polyurethane) but it's better than no fat at all isn't it?

09-13-2002, 01:37 AM	#17
atrahasis Regular Member Join Date: Mar 2002 Location: South of Sahara Posts: 216	oops! Flood [ September 13, 2002: Message edited by: Black Moses ]</p>

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09-12-2002, 10:12 AM	#15
KC Senior Member Join Date: Mar 2002 Location: San Narcisco, RRR Posts: 527	From what I've seen of AAT, it is a case of hyperadaptationism, where every trait, no matter how insignificant must have positive adaptive value, and thus requires an evolutionary just-so story to explain it. Cheers, KC

09-13-2002, 02:16 AM	#19
Stephen T-B Veteran Member Join Date: Apr 2002 Location: Leeds, UK Posts: 5,878	Dear Wyz - I assure you I haven�t a better handle on this simply because I spoke to Morgan, but I think the Savannah scenario has insufficiencies. Vorkosigan evoked kangeroos in his post as an example of a savannah animal that adopted bi-pedalism but even in my ignorance I can tell that there is a difference between what they do and what humans do. They have very large back legs, I seem to remember, which enables them to leap along at about 30mph. So they overcame ther inherent disadvantages of bi-pedalism in terms of speed by developing extremely powerful hind limbs. The only animals we can outrun, of any decent size, are sloths and I don�t think there were a lot of those to catch and eat on the savannah. Vorkosigan also mentioned hippos, elephants and rhinos as being hairless. I didn�t think the hippo was a savannah animal. I thought it spent most of its time in the water. And is it known that the distant relatives of the elephant and rhino were not water-loving creatures? Morgan thinks they were. The cartiliginous shield which protects our nostrils is a very strange structure. What advantage might it have had on the savannah? We can see quite clearly that when a human swims, it protects the nasal passages from an ingress of water. On the savannah, did it keep the dust out? Not very well, or perhaps humans would be less prone to hay fever. Duvenoy wrote: �Bi-pedal locomotion is indeed handy for sloshing around in the shallows, but it is also highly advantagous in the predator populated, high grasses of the African savannahs.� OK, so why don�t baboons walk around on their hind legs? Why doesn�t anything on the savannah walk around on its hind legs, apart from the kangeroo? And if height were a real advantage, humans didn�t do particularly well at acheiving it. Presumably height would have had a survival advantage: taller specimens would have survived better and bred more successfully and humans would have got really tall. But how tall were our early ancestors? I sense closed minds here. The Aquatic Ape suggestion (calling it a theory, and thus elevating it to the status of a proper scientific theory is clearly wrong) could, I suggest, get us thinking more constructively and creatively than has hitherto been in evidence. And why, I wonder, such passionate insistence on the savannah suggestion? What is it about the savannah that makes scientists think it answers all the questions provoked by the features which so clearly distinguish us from any other mammal (and which, I might mention, allowed those Middle Eastern Bronze Age sheepherders to think we were gods, not animals.)

09-13-2002, 02:40 AM	#20
seanie Veteran Member Join Date: Jul 2002 Location: Edinburgh. Scotland Posts: 2,532	I'm not holding a torch for AAT but some of the criticisms seem unfair to me. Some of it seems to be along the lines of 'well that's not an adaptation for an aquatic environment because such and such an aquatic mammal doesn't have it and they're much better suited.' But that doesn't seem a fair comparison. The only valid comparison is whether any supposed adaptation would've been better for an aquatic environment in comparison to the common ancestor of us and chimps. And it doesn't have to be a staggering improvement just better. Fat may be a crappy insulator (certainly compared to foamed polyurethane) but it's better than no fat at all isn't it?

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