our ancestors are not supposed to be the apes or of some same kind!

[Mokele]

It only says that some H. sapiens features are the result of adaptations to moving better thru water. It doesn't say humans lived exclusively in water.

 

You missed the point: their argument about hair direction is that it evolved to reduce hydrodynamic forces, therefore claiming that reducing hydrodynamic forces was a selective pressure. If that selective pressure was present, we would expect to see major changes in overall morphology relating to streamlining, but we don't. Basically, they're picking and choosing, claiming drag affected the evolution of hair, but somehow miraculously missed having any effect at all on the far larger cause of drag, body shape.

 

As for being fully aquatic, that has nothing to do with it. Streamlining is present in plenty of amphibious species; hell, hippos are at least rounded. And if they just waded, the velocities of the water would have been too low for hair to matter, and even if it did, then we'd have hair on our legs pointing backwards, not downwards.

 

I'm not saying this disproves AA, only that the hair-direction argument is bunk. If there was enough drag for hair to be a factor, there was enough drag to make body shape a factor too, and a much bigger one at that.

 

Furthermore, hair would make no difference unless they were swimming fast; drag is proportional to velocity squared, which is why boxfish can look like they do, but dolphins, ichthyosaurs and sharks all look the same. If they're claiming hair was affecting drag, then they're claiming fast movement through an aquatic environment, period. And that means selective pressure on body shape, which we see no evidence of.

 

It's like claiming that color is being selected on, but only for the animal's left side. If you postulate a selective pressure, and it affects one thing but not others, you need a damn good reason. If you postulate that drag was a selective pressure, you need a damn good reason why hair (<1% of drag) was affected while body shape (>80% of drag) was not. Even gene flow can't explain it, because it would have tended to dilute/delay both adaptations, and body shape would have had a *much* higher selection coefficient for simple mechanical reasons (plus body shape has more natural variation and phenotypic plasticity anyway).

 

What I see in your post is essentially equivocating: when a trait fits an aquatic lifestyle, it's because they swam a lot, but when it doesn't, it's because they swam a little. AA needs to pick a damn position. If they just waded in the shallows, then they would *not* have needed sleek hair or to hold their breath, and if they swam a lot, then would *not* have kept their ungainly, poorly streamlined primate form. Damned if you do, damned if you don't.

 

Mokele

[CDarwin]

Ok, I freely admit that I am but the layest of amateurs at these things, but I have a problem.

 

In the (mild) statement above about AAH, I don't find anything offensive or inherently false in it. There is a consensus that hominids lived in very small groups -- extended families. So, yes some of these groups of hominids (of successive species) would have lived along streams, lakes, or the ocean and attempted to exploit the food resources there.

 

Sure, but doesn't AA also require:

 

The hypothesis that water has acted as an agent of selection in the evolution of humans more than it has in the evolution of our ape cousins.

 

Now where is the evidence, circumstantial or otherwise, to support that? Plenty of apes live along streams and lakes today, and during that massive Miocene hominoid radiation I'm sure some lived beside the ocean too. Does evidence to support half a hypothesis count as supporting all of it? The question is honestly not just rhetorical.

[lucaspa]

You missed the point: their argument about hair direction is that it evolved to reduce hydrodynamic forces, therefore claiming that reducing hydrodynamic forces was a selective pressure. If that selective pressure was present, we would expect to see major changes in overall morphology relating to streamlining, but we don't. Basically, they're picking and choosing, claiming drag affected the evolution of hair, but somehow miraculously missed having any effect at all on the far larger cause of drag, body shape.

 

No, I didn't miss the point. The point was that there was "evidence for" AAH. What you are trying to do is introduce "evidence against. You are saying that a valid deduction of AAH Absence of these modifications is evidenmce against.

 

I'm not sure your objection is valid under the "mild" form of AAH. Mild AAH is not even saying that hominids were "amphibious" (to use your words). They are still mainly terrestrial but are spending time swimming, diving, and wading. Therefore modifications would be limited because any adaptations to true amphibious or aquatic morphology would inhibit movement on land. After all, hippos aren't very mobile on land, are they? Velocities would presumably matter for swimming and diving.

 

then we'd have hair on our legs pointing backwards, not downwards.

 

But in swimming and diving, downwards for walking is backwards for swimming and diving, isn't it?

 

I'm not saying this disproves AA, only that the hair-direction argument is bunk. If there was enough drag for hair to be a factor, there was enough drag to make body shape a factor too, and a much bigger one at that.

 

then they're claiming fast movement through an aquatic environment, period. And that means selective pressure on body shape, which we see no evidence of.

 

That does not follow. Again, mild AAH is not saying hominids are being dolphins or sharks. They are not spending nearly that amount of time in the water. AND, if what I am saying about disruptive selection is accurate, then we have other small groups of hominids in a terrestrial environment facing adaptations to that environment. That is what disruptive selection is all about: a species faces different, even opposing environments, over its range. Thus selection tries to adapt each subpopulation to the particular environments. But gene flow between the subpopulations opposes this and forces a compromise morphology that is not perfectly adapted to any particular environment.

 

If you postulate that drag was a selective pressure, you need a damn good reason why hair (<1% of drag) was affected while body shape (>80% of drag) was not.

 

Are we sure body shape wasn't affected? After all, compared to erectus or neandertals, sapiens is "gracile". That is, sapiens is longer and leaner. Wouldn't that be less dray for swimming than short and stocky? It works for ships. Now, the alternative hypothesis is that longer and leaner is more efficient in a hot environment -- less cross section for heating by the noonday sun and more body area in shade that can sweat. After all, the Masai are the longest and leanest of all human populations, and they don't exploit resources in rivers, lakes, or the sea. Or could it be that both selection pressures worked to give sapiens their general body shape?

 

What I see in your post is essentially equivocating: when a trait fits an aquatic lifestyle, it's because they swam a lot, but when it doesn't, it's because they swam a little. AA needs to pick a damn position. If they just waded in the shallows, then they would *not* have needed sleek hair or to hold their breath, and if they swam a lot, then would *not* have kept their ungainly, poorly streamlined primate form. Damned if you do, damned if you don't.

 

My post was trying to look at the mild form of AAH and test it. The extreme forms of AAH don't work. You and I both agree that the evidence is against an amphibious species in hominid evolution, much less a fully aquatic species. But could SOME traits that differentiate us and modern apes be explained by selection for moving thru water? That hypothesis is fairly innocuous and does not involve totally re-writing the hominid family tree. Also, it is possible. We can argue about which traits exactly but I don't see a way to falsify the mild form of AAH.

 

And with disruptive selection, yes, you can have traits because "they swam a lot" and traits because "they swam a little" or not at all. Different subpopulations did different things in different environments. I haven't seen any AAH proponent consider disruptive selection (I'm not even sure they know it exists).

 

And the mild form does not give up a majority of time spent in terrestroid existence -- even for those exploiting resources under water. Even the guys today who dive for pearls do so for only 8 hours a day and spend most of their time on land. So I see no objection to keeping the basic "ape form". And, as I have said, we are more streamlined than a chimp, aren't we?

[lucaspa]

Sure, but doesn't AA also require:

 

The hypothesis that water has acted as an agent of selection in the evolution of humans more than it has in the evolution of our ape cousins.

 

Now where is the evidence, circumstantial or otherwise, to support that? Plenty of apes live along streams and lakes today, and during that massive Miocene hominoid radiation I'm sure some lived beside the ocean too. Does evidence to support half a hypothesis count as supporting all of it? The question is honestly not just rhetorical.

 

Apes live along streams, but no modern ape I know of fishes or dines on aquatic creatures such as clams or crayfish. Sapiens does. I'm not sure how far back evidence of this exploitation of food derived from bodies of water goes. We should do some research to find out. Look to see the oldest fish bones discovered at hominid sites. There is evidence that erectus built boats: 4. R Kunzig, Erectus afloat. Discover 20: 80, Jann. 1999. Data indicate that H. erectus used boats to get to Indonesia 800,000 years ago.

 

Now, it is implausible that erectus would have invented boats for the sole purpose of getting to Indonesia (or any other island). Instead, it is reasonable to hypothesize that erectus began building boats so that they could get to better fishing or clam beds. And primitive people who go out on boats learn how to swim. The ones that don't are selected against by drowning when they fall off the boat.

 

Oh, this site says evidence of fish bones goes back to H. habilis -- 2 million years ago and at least 2 species ago in hominid evolution. http://www.medicalnewstoday.com/medicalnews.php?newsid=38009

[CDarwin]

Bonobos actually eat fish, or at least Fleagle's Primate Evolution and Adaptation says so, and there are monkeys that eat crabs and shellfish and swim extensively (the talapoin and proboscis monkeys come to mind immediately). I suppose what distiguishes humans is their use of ocean environments.

[lucaspa]

Bonobos actually eat fish, or at least Fleagle's Primate Evolution and Adaptation says so, and there are monkeys that eat crabs and shellfish and swim extensively (the talapoin and proboscis monkeys come to mind immediately). I suppose what distiguishes humans is their use of ocean environments.

 

Cool. You may have found falsification of even the mild form of AAH! Let's test the falsification to see if it holds up. (yeah, everything gets tested in science.)

 

I too find that bonobos occasionally eat small fish: http://www.sandiegozoo.org/animalbytes/t-bonobo.html "Bonobos eat leaves, stems, fruits, worms, insects, and sometimes small fish." Of course, the site also emphasizes that bonobos are a separate species than chimps, so I don't know who their evolutionary ancestor is. Do they share the same common ancestor with humans as chimps or are bonobos a speciation from chimps? That would tell us how long they have had to adapt to the diet.

 

Also, it doesn't look like fish are an important part of the diet nor do we have information on how the bonobos get their fish. Do they go swimming or wading after them?

 

What I'm getting at here is 1) how severe is the "selection pressure" for aquatic movement in bonobos and 2) how long, in evolutionary terms, bonobos have had to acquire adaptations. I do note the website says "bonobos are more slender and have smaller heads and smaller ears." Wouldn't those traits contribute to streamlining in swimming? Also, how hairy are bonobos compared to chimps?

 

Now, the information about the talapoin and proboscis monkey are potentially very potent falsifiers of AAH. Have you looked at either to see if there are adaptations -- compared to other monkeys -- for moving thru water?

[CDarwin]

It took a while, but I have prepared my response.

 

Of course, the site also emphasizes that bonobos are a separate species than chimps, so I don't know who their evolutionary ancestor is. Do they share the same common ancestor with humans as chimps or are bonobos a speciation from chimps? That would tell us how long they have had to adapt to the diet.

 

I get the feeling from what I read that bonobos are generally held to be neotenic derivations of chimpanzees. Brain Shea’s blurb on neoteny in The Cambridge Encyclopedia of Human Evolution indicates thusly, and so does Fleagle in Primate Adaptation and Evolution, citing another article by Brain Shae. I found this article too, which is a bit more conservative but broadly supports bonobos speciating from chimpanzees through neoteny.

 

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJS-4MRN9P6-1&_user=10&_coverDate=01%2F05%2F2007&_alid=546119161&_rdoc=1&_fmt=summary&_orig=search&_cdi=6886&_sort=d&_docanchor=&view=c&_ct=9&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=4f41d7c509e1cb8a2526621e02072c08

 

Also, it doesn't look like fish are an important part of the diet nor do we have information on how the bonobos get their fish. Do they go swimming or wading after them?

 

It seems: “… two river systems that converge to define the extent of bonobo distribution: the Congo-Zaire-Walaba River and the Kwa-Kasai-Sankuru River (Kortlandt 1995). These rivers serve as an effective geographical barrier for the apes as they are not known to swim (though they have been seen wading into waist-deep water) (Kortlandt 1995; Myers Thompson 2002).”

 

http://pin.primate.wisc.edu/factsheets/entry/bonobo

 

They seem to be more swamp species: “Bonobos exploit the swampy rainforest south of the Zaire River. They forage in swamp meadows on a thin underlying peat layer.”

 

What I'm getting at here is 1) how severe is the "selection pressure" for aquatic movement in bonobos and 2) how long, in evolutionary terms, bonobos have had to acquire adaptations.

 

The answers seem to be 1) not particularly strong and 2) 10-12 million years according to this:

 

http://www.springerlink.com/content/f6pnyhg0h3lg2acq/

 

Also, how hairy are bonobos compared to chimps?

 

Anecdotally? They were once called the ‘bald chimpanzee’ apparently (http://pin.primate.wisc.edu/factsheets/image/21) and they do seem to appear less hairy. I don’t know if that’s ever been quantified.

 

Now, the information about the talapoin and proboscis monkey are potentially very potent falsifiers of AAH. Have you looked at either to see if there are adaptations -- compared to other monkeys -- for moving thru water?

I know talapoins have some webbing between their fingers and toes, from Walker’s Primates of the World. They aren’t any more noticeably hairless than the other guenons, though. Interestingly enough, they too are thought to be neotenic.

 

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJS-4G3KBHX-4&_user=10&_coverDate=09%2F30%2F1992&_alid=546121717&_rdoc=1&_fmt=summary&_orig=search&_cdi=6886&_sort=d&_docanchor=&view=c&_ct=1&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=1dec2b60697425fb42f0418fb79ea5e6

 

Proboscis monkeys and Allen’s Swamp monkey also show webbing on their feet, and macaques, baboons, mangabeys, and a plethora of New World Monkeys are known to swim. Macaques are especially accomplished and many species swim into the ocean. That all came from various books at the UT Library (Hershkovitz’s Living New World Monkeys, Ankel-Simons’s Primate Anatomy, and Schultz’s Primate Lives would cover all of them I believe), I don’t think I could find websites. I may not have spelled all those names correctly; I’m very tired.

[lucaspa]

It took a while, but I have prepared my response.

 

It looks like you did a good job of it, too! So let's see if they really falsify the "mild" version of aquatic ape. Remember, we agree that the extreme version is falsified.

 

First the bonobos:

 

It seems: “… two river systems that converge to define the extent of bonobo distribution: the Congo-Zaire-Walaba River and the Kwa-Kasai-Sankuru River (Kortlandt 1995). These rivers serve as an effective geographical barrier for the apes as they are not known to swim (though they have been seen wading into waist-deep water) (Kortlandt 1995; Myers Thompson 2002).”

 

http://pin.primate.wisc.edu/factsheets/entry/bonobo

 

They seem to be more swamp species: “Bonobos exploit the swampy rainforest south of the Zaire River. They forage in swamp meadows on a thin underlying peat layer.”

 

The answers seem to be 1) not particularly strong and 2) 10-12 million years according to this:

 

If bonobos are a speciation of chimps, it has to be less than 8 million years, since that is when we have the common ancestor of chimps and humans. So bonobos must split from chimps later than that.

 

That's a disagreement with your source, of course. You are just quoting them.

 

BUT, since bonobos don't spend much time in water, we would not expect much selection pressure for adaptations. So the fact that bonobos don't have adaptations does not falsify "mild" aquatic ape theory. However, you did say that, anecdotally, they are "less hairy". But since that hasn't been quantified as hair follicles/square cm (as you noted) we can't conclude anything about this in relation to mild aquatic ape.

 

All in all, it seems bonobos neither falsify nor support mild aquatic ape.

 

I found this article too, which is a bit more conservative but broadly supports bonobos speciating from chimpanzees through neoteny.

 

An aside here: you don't "speciate through neoteny". Rather, the adaptations that differentiate the new species from the old look like they result from neoteny. I know that this may sound like trivial quibbling, but it's not. Neoteny is not a method of speciation. Rather, the adaptations are the result of suppressing later development -- giving rise to a new phenotype.

 

So, now onto monkeys.

 

I know talapoins have some webbing between their fingers and toes, from Walker’s Primates of the World. They aren’t any more noticeably hairless than the other guenons, though. Interestingly enough, they too are thought to be neotenic.

 

OK, this somewhat supports mild aquatic ape, since one claim of mild aquatic ape is that our neotenic traits are the result of selection for moving thru water. It also shows that there are adaptations to water even tho the majority of life is spent on land.

 

It's not overwhelming support, just mild support. A failure to falsify might be a better way of putting it.

 

Proboscis monkeys and Allen’s Swamp monkey also show webbing on their feet, and macaques, baboons, mangabeys, and a plethora of New World Monkeys are known to swim. Macaques are especially accomplished and many species swim into the ocean.

 

You did a good job. It's not an ability to swim per se, but whether they spend enough of their time swimming in order to get resources to provide a selection pressure for adaptation.

 

Now, the argument could be made that partially making a living from water does result in adaptations in the monkeys. But the adaptations are webbing, NOT hairlessness. OTOH, we don't have a lot of information on the amount of hair and, as I recall, don't macaques live in colder climates and the water is going to be colder?

 

IMO, we don't have either decisive support nor decisive refutation of mild aquatic ape. Yes, there are adaptations but they are not the same ones we see in humans. Could human hairlessness be an adaptation to partial living in water? Yes. But must it be such an adaptation? No, because proboscis monkeys and talapoins still have their hair.

 

I tend to think that our hairlessness comes from being cursorial hunters and the need to get rid of body heat. http://www.dooyoo.co.uk/discussion/evolution/370800/

 

There are very few cursorial hunter species, but the ones that are --dogs and wolves -- have fur! So that puts the cursorial hunter hypothesis in the same boat as mild aquatic ape in explaining the human lack of hair.

[bombus]

 

Now, the information about the talapoin and proboscis monkey are potentially very potent falsifiers of AAH. Have you looked at either to see if there are adaptations -- compared to other monkeys -- for moving thru water?

 

The proboscis monkey has a flap over the nose to prevent water entering via the nostrils when swimming. It has become a sexy to other proboscis monkeys!

 

Actually the proboscis monkey is heralded by AAH supporters as evidence for the theory.

[bombus]

The AAH is part of the story. There is ssooo much evidence supporting it, I can't be at all bothered to start listing it here, but the point is, and it has been well made above, is that the AAH does not in any way exclude the other theories (Savannah and Neotenic), and in fact supports them too as it explains the things they don't.

 

I guarantee in 50 years time it will be one of the most accepted theories...

[CDarwin]

Big theoretical approaches like AA (or recapitulation, for that matter) don't get unseated by simple enumeration of contrary evidence. They become untenable theoretically. The current push in human evolutionary thought is for mosaic evolution, different traits evolved at different times for different reasons, and the fossil record supports this. Opposable thumbs are 50 million years old, bipedalism 10 million, big brains maybe 2 million, language maybe a few 100,000.

 

AA is a big umbrella hypothesis that tries to explain great numbers of traits with a single event. Current thinking (and what the evidence currently suggests) doesn't sync well with that.

[lucaspa]

The proboscis monkey has a flap over the nose to prevent water entering via the nostrils when swimming. It has become a sexy to other proboscis monkeys!

 

Actually the proboscis monkey is heralded by AAH supporters as evidence for the theory.

 

I know, but is it support? From my previous post:

 

"Yes, there are adaptations but they are not the same ones we see in humans. Could human hairlessness be an adaptation to partial living in water? Yes. But must it be such an adaptation? No, because proboscis monkeys and talapoins still have their hair."

 

So, proboscis monkeys have a flap over the nose. Why don't humans? Also, humans are hairless. Proboscis monkeys aren't.

 

Do you see where I'm going here? Proboscis monkeys spend so much time swimming that they have a special adaptation to keep water out of the nose, but they have hair! If humans are supposed to have adaptations to living in water, why aren't they the same adaptations as talapoins and proboscis monkeys?

[lucaspa]

The AAH is part of the story. There is ssooo much evidence supporting it, I can't be at all bothered to start listing it here, but the point is, and it has been well made above, is that the AAH does not in any way exclude the other theories (Savannah and Neotenic), and in fact supports them too as it explains the things they don't.

 

I guarantee in 50 years time it will be one of the most accepted theories...

 

Well, so much for skeptical and critical thinking! All you are doing is cheerleading. How can you "guarantee"? What will you put up as collateral?

 

From what I see right now, and what we have looked at in this thread, "strong" AAH is impossible. It is refuted by the data. The question is whether "weak" AAH survives and tells us something useful.

 

First, there isn't that much evidence supporting weak AAH. What AAH gives us is circumstantial evidence, but no direct fossils showing humans making a major living in water. Second, you forget that "evidence for" doesn't count except when it is the result of an honest attempt to falsify the theory. AAH supporters don't try to falsify. They simply take the "supporting" evidence and ignore any data that is contrary.

 

Look at the idea that adaptation to water accounts for hairlessness in H. sapiens. They look at a few mammalian species -- such as hippos -- as "support", but ignore the talapoin and proboscis monkey.

 

Third, in order for a theory to be good, it MUST forbid. When you say AAH doesn't forbid anything, you are saying it is a very bad theory. You are basically saying that there is no way to falsify AAH.

 

Tell me, what evidence would falsify AAH? Can you specify any such evidence?

[lucaspa]

Big theoretical approaches like AA (or recapitulation, for that matter) don't get unseated by simple enumeration of contrary evidence. They become untenable theoretically. The current push in human evolutionary thought is for mosaic evolution, different traits evolved at different times for different reasons, and the fossil record supports this. Opposable thumbs are 50 million years old, bipedalism 10 million, big brains maybe 2 million, language maybe a few 100,000.

 

AA is a big umbrella hypothesis that tries to explain great numbers of traits with a single event. Current thinking (and what the evidence currently suggests) doesn't sync well with that.

 

CDarwin, you are enumerating contrary evidence! If our traits are supposed to be due to AN episode where hominids were aquatic, then having traits appear at widely separate times in our evolutionary history is evidenece against the theory: there isn't ONE episode of aquatic living.

 

Now, AAH might be able to weather that by saying that humans lived NEAR water for their entire evolutionary history. But the fossil evidence contradicts that, too.

 

BTW, recapitutalation was refuted by enumerating contrary evidence: fetus after fetus that did not undergo recapitulation.

[CDarwin]

CDarwin, you are enumerating contrary evidence!

 

Yes... I know. And as you saw, it was something of a waste of time. Any contrary evidence can simply be incorporated as an exception or by softening the theory.

 

If our traits are supposed to be due to AN episode where hominids were aquatic, then having traits appear at widely separate times in our evolutionary history is evidenece against the theory: there isn't ONE episode of aquatic living.

 

Now, AAH might be able to weather that by saying that humans lived NEAR water for their entire evolutionary history. But the fossil evidence contradicts that, too.

 

And that's my point. AA doesn't fit with mosaic evolution, which is just the modern accepted interpretation of evidence that's been here for half a century.

 

BTW, recapitutalation was refuted by enumerating contrary evidence: fetus after fetus that did not undergo recapitulation.

 

Not according to Stephen Jay Gould. Recapitulationsts would accept within their theory a broad range of exceptions, and due to the enormity of the body of evidence, they could always get away with it since just as many facts could be found to support Recapitulation. They also softened it considerably. After a while whole organisms weren't seen to recapitulate, only individual organs, and of course with exceptions all dubbed as 'cenogenesis' (adaptive evolution) as opposed to 'palingenesis' (true, or progressive evolution).

 

Mendellian genetics and the shift to experimental embryology undid Recapitulation.

 

The reason I mentioned Recapitulation specifically was because I got the notion that big theories are usually undone by a change in theoretical outlook from Phylogeny and Ontogeny, which was about that.

[lucaspa]

Yes... I know. And as you saw, it was something of a waste of time. Any contrary evidence can simply be incorporated as an exception or by softening the theory. ...Recapitulationsts would accept within their theory a broad range of exceptions, and due to the enormity of the body of evidence, they could always get away with it since just as many facts could be found to support Recapitulation.

 

This is what you have to look out for: equating the theory to the people (Recapitulationists in this case) that advocate the theory.

 

Those are different. There are two different statements:

1. The theory is refuted by contrary evidence.

2. The people advocating the theory admit the theory is refuted by contrary evidence.

 

Those are not the same thing. #1 can be true but the people don't admit the theory is falsified and come up with all kinds of ways to avoid admitting the theory is refuted.

 

I strongly recommend the book Theories on the Scrapheap by John Losee. He is a philosopher of science and wrote the book, obviously, for one of his classes as a textbook. But it is very readable.

 

Theories ARE discarded. Science is littered with theories that are no longer considered valid. So the question for the philosophy of science -- and scientists -- is: how does this happen? How does the scientific community decide that a theory is wrong and discard it? How does the scientific community decide that a theory should be replaced with another one?

 

BUT, not all the people advocating the theory have to admit that the theory is wrong. That tells us something about the personality of the people, but not about whether the theory is correct or incorrect.

 

And that's my point. AA doesn't fit with mosaic evolution, which is just the modern accepted interpretation of evidence that's been here for half a century.

 

This isn't the issue. After all, mosaic evolution could be wrong. Just because a theory is "accepted" doesn't mean it is correct. Science is composed of theories that were once accepted and are now wrong. What you want to say is: "The evidence that supports mosaic evolution also contradicts AAH."

 

Not according to Stephen Jay Gould. ... Mendellian genetics and the shift to experimental embryology undid Recapitulation.

 

The article I read by Gould -- discussing Haeckel's drawings -- made it clear that recapitulation was rejected by the consensus of the scientific community from the beginning. Scientists 1) knew that the data was faked and 2) made the potent argument that you couldn't line up evolution as a ladder. If we were looking at it from the pov of an elephant, then recapitulation would be different. I got this from one of Gould's essays and it post-dates the book Phylogeny and Ontogeny. It appears that Gould's position changed with time and new evidence.

 

The reason I mentioned Recapitulation specifically was because I got the notion that big theories are usually undone by a change in theoretical outlook from Phylogeny and Ontogeny, which was about that.

 

Define "big theories". What makes a theory "big"? How do we draw the line between "big" and "little" theories?

 

What you are looking at with "big theories" is exactly what I pointed out above: people trying to avoid rejection of their pet theory.

 

Thomas Kuhn advanced the idea that theory replacement happened by "revolution". He called the theories "paradigms". So, Kuhn proposed that there were "paradigm shifts" and that emotion or "theoretical outlook" was the critical determinant.

 

Kuhn's proposal came under criticism. Some of the historical examples Kuhn used were shown to be other than Kuhn portrayed and other examples showed that theories were replaced solely on the data. In the philosophy of science, how science has worked in the past in particular examples is the data. So the data refuted Kuhn's idea of "paradigm shift".

 

Kuhn modified the theory and said "paradigm shift" applied only to large, encompassing theories. And here we have your "big theories".

 

It takes a while for new ideas to shift to the biological sciences. So 50 years philosophers of science have discarded "paradigms" and "paradigm shifts" you will still see "paradigm" in the biomedical literature today.

 

There is also an idea put forth by Imre Lakatos that science works in research programmes (and no, that's not a misspelling). Lakatos' idea is that theories are not discarded until there is a replacement theory. That also seems to be part of what you are saying above. However, Losee shows several examples where theories were discarded without a replacement.

 

Bottom line, when discussing theories it is always best to

1. Put forth evidence that refutes or falsifies a theory.

2. Never confuse the theory with the people who advocate it. In this thread I doubt Bombus is ever going to be convinced that AAH is invalid. But you and I don't care if Bombus is ever convinced. What we care about is AAH itself. By that I mean the collection of statements that is AAH. AAH advocates can modify AAH to the point that it doesn't contribute anything or deny the evidence. It may provide emotional comfort to them to do that. You and I don't care about that. What we care about is how humans evolved.

 

If that means that mosaic is wrong, so be it. If that means that AAH is wrong, so be it. Right now, as you and I look at the data, strong AAH is falsified. Weak AAH might still be valid. And, we still don't have a theory with overwhelming data as to why humans are hairless.

[Sayonara]

I'll ask the question again: if the aquatic ape theory is gaining support, where are the papers?

 

This thread is an elegant illustration of the idea that supporters != support.