atrahasis

I wish everybody around here would think like this. Lets not dismiss an hypothesis no matter how crazy it might look at first..

For example the guy who came up with the continential drift theory was at first very much critisized...but it later turned out that continential paltes actually drift with time..

Let the wise teach the mystery to the wise

Ergaster

I remember reading Morgan's first book, many years ago, and thinking how neat it was. Sounded good to me.

And then I formally studied hominin and hominoid evolution, and the more I learned, the less likely it became. The most significant problem is that it simply does not correspond with *all* the evidence. AAT proponents are great at picking and choosing bits of evidence, and constructing great-sounding scenarios, but they ignore evidence that does not fit their scenario, and most of their ideas simply are not testable. Nor does it seem to change much with changing scientific knowledge.

For example, I notice some folks here are still flogging the inadequacy of the "savanna hypothesis"--that is, the notion that key hominin adaptations are a response to savanna environments. Only problem is, the professionals have known that the "savanna hypothesis" is wrong for about a decade. So how come the AAT-ers haven't got with the program yet? Why are they using something that professionals know is wrong as evidence against a hypothesis that the professionals don't believe? Let's update the arguments, here!

Anyway, I think I'll cobble something together in the next day or two, and you guys can pick it apart if you want. I don't spend a lot of time bothering with AAT--and quite honestly, the *only* reason that AAT has no currency with professionals is for the very simple reason that it does not correspond with all the evidence we have of hominin evolution. In light of what we know, it makes no sense.

And it really is not equivalent to "continental drift". When Wegener proposed it, his fellow geologists were quite willing to concede that the continents sure *looked* like they moved around; Wegener's problem was that he couldn't adequately explain HOW they moved. AAT is nothing like that; the evidence just isn't there to begin with.

There are a lot of crackpot ideas out there in science (just check with the physicists--they see them all the time!). Wegener aside, history shows us that the *vast* majority of nutty ideas always and ever will remain nutty ideas.

Oolon Colluphid

Bzzzt! False analogy!

BM, Wegener's 'continental drift' won out in the end because over the intervening 40 years or so the evidence accumulated in its favour, especially a feasible mechanism.

Morgan proposed her hypothesis in, what, the 60s? -- it gets a mention in Morris's Naked Ape IIRC -- and as far as I know, there's hardly been a massive amount of evidence accumulate to support it since. Hominid fossils still keep turning up in the Rift Valley. The AAH is still only a neat idea -- one I have sympathy for (like, why the fascination with beaches?), but nothing more.

Cheers, Oolon

Peez

I am well aware of the definitions of "mystery", I wanted to know in what sense the author thought that human evolution is a "mystery". The web page you referenced gives nine definitions, of which eight do not apply at all. The other one applies only as much as it applies to just about everything in science. No, thank you, I do not need the definition of "bizarre". My point was that the argument in question make little sense and is only likely to be proposed by someone who does not understand, has a definite bias, or both. I did not imply that only a creationist could make that sort of argument, indeed there are many others who do (UFOlogists, for example). I am well aware of that, and I never suggested otherwise. I was merely pointing out that just about anything that is internally consistent is a "possible truth". You did say "I will be eager to hear what you guys have to say about this". My point is that the author seems to be unaware of this fact. I addressed this already, what was the problem with my explanation? Nice picture, what is your point? You are welcome.


Peez

seanie

Thinking about it one of the claims is that humans are exceptional swimmers right?

And the counter claim is that actually most terrestial animals can swim so in that respect we're nothing special.

Well one problem with the original claim would seem to be hyperbole. It's the use of the word 'exceptional'. Compared to what? A more defensible claim would be simply that we evolved to be 'better' swimmers. That a selective pressure drove us to be better swimmers than our ancestors.

The trouble with the counter claim is that it's neither here nor there. So most animals can swim. So what? The question is is there any reason to suggest that humans can swim better than the common human/chimp ancestor? And if so is it a direct result of evolving in a semi-aquatic environment?

Even if we are better swimmers than chimps it doesn't necessarily mean we evolved that way because there was a selective pressure to be good at swimming. A better ability to swim could be incidental. A by-product of a morphological change driven by different selection pressures.

MrDarwin

Regarding human hairlessness, I don't think the "aquatic ape" theory explains it very well at all. First of all, human body hair varies quite a bit, in both men and women, and there are plenty of men who have lots of body hair. In most men this hair follows a definite pattern: beard, chest, legs, to a lesser extend arms and back (although even here I've seen lots of men who are approaching apes in their body hair).

Secondly, and probably more significant, our "hairlessness" is strongly linked to our sexual dimorphism. Women are significantly less hairy than men. And this simply wouldn't make sense with "aquatic apes" because there would be no adaptive advantage (that I can see) to this being sex-linked.

What I find more likely is that, for whatever reason, early human men preferred hairless (or less hairy) women, and the relative hairlessness of men compared to other apes is a byproduct of this sexual selection. Or, to put it another way, women who were less hairy were more successful at mating and having babies--for whatever reason. It may have even been a genetic accident, perhaps occurring during or shortly after a near-extinction event when Homo sapiens was reduced to a very small population(suppression of body hair seems to be due to a mutation in a single gene, although even with the gene there are gender differences in body hair distribution).

Edited to observe additionally that human body hair is also age-linked: children are almost entirely hairless except for their heads, and develop body hair at puberty. And body hair continues to increase throughout our adult lifetimes (as I'm discovering as hair sprouts on my back and my earlobes...)

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seanie

The hairlessness thing does seem problem to me.

Even in a semi-aquatic environment hair would seem a useful thing, especially if you're spending time on land and in water. However I suppose it depends on the specific environment. In a very hot climate presumably less hair would seem less of a problem and possibly an advantage, whether or not you were spending periods of time in water.

MrDarwin

Some questions:

Do we really know that chimpanzees and other apes are poor swimmers? Maybe it's true, but I'd like to see some better documentation.

Second, if they are, just what does it mean? My recall is that they are primarily forest dwellers who probably rarely see bodies of water large enough to swim in. Perhaps they are not good swimmers because there is no reason for them to be? It would be interesting to find out if our more distant primate relatives are also good or poor swimmers.

And neither here nor there: most cats are also terrified of the water, but once in it they are excellent swimmers.

seanie

Not Fluffy.

May she rest in peace.

Wyz_sub10

If, indeed, we had to catch them at all. Early humans could well have been scavengers to a degree. But nevertheless, humans hunt in packs. They do not need to be as fast as their prey. Few animals in the savannah are as fast as antelopes, but they're prey to many.

It doesn't work well for water, either. I taught swimming for years and one of the things you have to teach young kids is how to beath properly when they swim, and how to submerge properly. Young kids (and many adults) always manage to get a snootful of water when they're splashing around.

Studies suggest that height is not genetic but based on nutrition. But even so, I'm not sure how this translates into a survival advantage.

Not at all. I have no bias against this theory. But the supporting observations are inadequate and the logic is questionable, if not lacking altogether. You do not promote the Aquatic theory simply by finding flaws in the Savannah theory. Even if all your Savannah observations were water-tight (pardon the pun) it still would not address the deficiencies in AAH.

This, I am assuming, is a general comment. Personally, I don't have much to say on the Savannah theory. I do think, however, that paleantology has given us some strong evidence for inland development.

I really do not advocate any particular theory, but I do think that AAH, as it stands, is not worth further consideration.

[Edited because I can't spell or use quotes properly.]

[ September 13, 2002: Message edited by: Wyz_sub10 ]

[ September 13, 2002: Message edited by: Wyz_sub10 ]</p>