AAH does not demand that “the entire population used water every day for massive amounts of time”, and it does not have to be so in order to work.

That’s what most AAT/H proponents will now say, but then you look at what features they claim are due to this “hardly in the water” lifestyle and you see that those features, like hair, fat, and several others, are found only in a very few fully aquatic mammals which have been fully aquatic for several times longer than hominids have existed. This means they are either actually claiming we spent an enormous amount of time in the water, or that somehow just being near water gave us characteristics found only in whales and serenia. At least Hardy was honest about the amount of time he thought our ancestors would have to have spent in water, but then he was a scientist, even though he did make many elementary errors of fact in his “aquatic ape” idea, just as he did in his telepathy and pyschic phenomena ideas.

The fact is that they also describe those characteristics inaccurately, and they really aren’t like those of aquatic or semi-aquatic mammals, and that’s just an additional nail.

Hair loss - you’re stressing the point that what we have is exactly what we don’t want entirely too much, especially since it’s not strictly true.

Look at aquatic and semi-aquatic mammals; they have either lots (most of the them, the vast majority of them in fact) or none (a very few fully aquatic mammals which have been fully aquatic for several times longer than hominids have existed).

I also have a problem with the notion that our hairloss - practically unique among the animal kingdom - was done by sexual selection. Why would hairloss be sexually selected for humans and not for any other ape?

That’s typically what you see in cases of sexual selection; for instance, why do lions have manes but other big cats don’t? (There is also a tendency toward less body hair in apes, compared to other primates.) But the most critical part is that when you see characteristics like fat or hair being due to environment, an aquatic environment specifically in this case, those chacteristics are set by the time the creature hits the water. Naturally. And they don’t vary between the sexes. Naturally. In humans, however, you find those characteristics change right at puberty and vary between the seses, which are hallmarks of sexual selection. This also leads to the odd internal inconsistency in the AAT/H: babies need to be aquatic to explain their fat, and non-aquatic to explain their larynxes; later, as children, they need to be non-aquatic again to explain their lack of fat and sebaceous glands, and aquatic to explain their larynxes. Women need to be far more aquatic than men to explain their fat and hair differences, but men need to be far more aquatic than women to explain their sebaceous glands. This contradictory jumble just doesn’t make sense, while all those things can be explained simply with non-AAT/H ideas: fat, hair, and sebaceous glands are sexually selected (they near all the hallmarks), the baby fat is unique to humans and no doubt due to our also unique to humans post birth development, especially brain development. And the larynx is now pretty conclusively shown to be due to selection for a deeper voice and is now known to not be unique to humans among primates, not to mention other mammals (others known, so far, include chimps, red deer and elk, koalas, “lions, tigers, and other members of the genus Panthera”, dogs, pigs, goats and monkeys, and even at least some birds, like roosters and cardinals. (It was thought otherwise until recently — 15-20 years ago — because most research on this was done by dissection, but newer research with imaging on living animals shows that the descended larynx is a common feature. And of course until relatively recently we concentrated most research on ourselves, or things of medical benefit to ourselves, which limited our knowledge about a range of non-human animals.)

And the majority of wading time for non human primates is not quadrupedal, it’s bipedal. Where on earth did you get that idea from?

From actual primate researchers’ actual reports on actual primate behavior. That’s what they find. A couple of AAT/H proponents have claimed otherwise, but Morgan did so on the basis of no research whatsoever and counter to the actual research (guess which position I accept?) and another fellow does so on the basis of 5 hours of observation at a zoo where bonobos reached very quickly into water (no more than a few seconds at a time for a total of 37 seconds) where he got radically different results from all other researchers who did hundreds of hours of observations in the wild. He doesn’t wonder at all (as any researcher should) why his results were so far different from everyone elses — other observation of bonobo populations show ranges of 0-24% of wading time done bipedally; and other apes, as well as monkeys, do so even less often. Again, guess which research I find most compelling, the many studies done by many dispassionate observers or the guy who thinks his numbers from 37 seconds of wading should be used in place of all other studies?

THIS thread has so thoroughly curbstomped the idea, largely due to anthrosciguy’s contributions, that Seth’s stubborn adherence to it is frankly making me question his judgment about everything, to the point where I’m considering an unsubscribe from his RSS feed. This just isn’t good scientific thinking on display…

I think this blog is great and I like Seth’s POV on quite a lot. But I know exactly how you feel. I too, as someone who knows a bit about anthropology and has spent more than little time in the water, am surprised, perhaps even a bit appalled as to Seth’s clinging to the very romantic, but highly improbably, theory of AA. But hey, we’re all human.

THIS thread has so thoroughly curbstomped the idea, largely due to anthrosciguy’s contributions, that Seth’s stubborn adherence to it is frankly making me question his judgment about everything, to the point where I’m considering an unsubscribe from his RSS feed. This just isn’t good scientific thinking on display…

Now, in response to what you’ve written: First off, you completely misunderstood the point I was trying to make about the crocodiles. I most certainly did not imply humans wrestling crocodiles. However, if a culture lives by crocodile invested waters, and have to use those waters as a food source, they are going to have to find ways to deal with those crocodiles. When I wrote about holding crocodiles’ jaws shut I was trying to illustrate a known way in which humans could deal with crocodiles, not to suggest that they valliantly went about daily wrestling crocodiles. Also, I was not trying to say that they definitively developed in Afar and that the Afar crocodiles were “special friendly non-hominid eating crocs”, but to suggest that not all cocodiles need be huge man eaters, and that there are crocodiles who are currenlty not extremely dangerous in the North east of Africa where it is likely that early humans developed. I thought I made myself very clear on that point, but obviously I did not. I apologize if you misunderstood me. I also never suggested that humans were like dolphins. I actually have absolutely no idea where that came from. What I actually said what that since dolphins can intimidate sharks, it would imply that sharks actually could be intimidated. Humans are like dolphins never even entered in to that. I did say that the Amo and Haenyo diving cultures dealt with shark attacks by punching them and by intimidation. However, that has nothing to do with humans being like dolphins. Also, the Amo and Haenyo cultures often will see the shark coming - which is why they can deal with them.

AAH does not demand that “the entire population used water every day for massive amounts of time”, and it does not have to be so in order to work. Even for a population that only used water as a food source, and did not enter it for massive amounts of time, selection would still be made to prevent drowning and to increase food getting efficeincy - by swimming, etc…After all, completely terrestrial mammals also have methods to prevent drowning, such as the diving reflex. Why would these selections not have increased in a population that was mostly terrestrial, but which used the water frequently as a food source? AAH does not depend on them practically living in the water, not by the slightest stretch of the imagination.

Hair loss - you’re stressing the point that what we have is exactly what we don’t want entirely too much, especially since it’s not strictly true. That would imply that out of the thousands of different types of hair and fur variations in the animal kingdom, humans have absolutely, catagorically the least efficiant form ever. Of course this is not true. That is not to say that our skin is as efficiant in the water as a dolphins, because it isn’t, not by any stretch of the imagination. You also make the rather simplistic point that hair is good, no hair is good, and what we have is terrible. This fails to distinguish bewteen the different types of hair. Of course an otter’s hair or a seal’s will be extremely efficiant in the water. But a housecat’s will not be nearly as efficiant. What you should be doing is comparing the efficiancy of chimpanzee and bonobo hair - and maybe gorillas and other monkeys for good measure- to humans in the water to see what is more efficiant. The question is not whether humans rank as aquatic in relation to aquatic mammals in the rest of the animal kingdom, but whether they rank as relatively aquatic in relation to apes. That question would easily apply to an ape’s fur. If a reliable experiment is done that says that what humans have is less efficient in the water than even a chimpanzee’s hair, then I will rest my case. However, your answer on hair is sidestepping the issue, and is not fully answering it in the context of the theory (or theories.)

I also have a problem with the notion that our hairloss - practically unique among the animal kingdom - was done by sexual selection. Why would hairloss be sexually selected for humans and not for any other ape? There would have to be a pretty strong reason. I have heard another somewhat similar theory that hairloss would be sexually selected because it would decrease parasites. But why would that be so for humans and not any other ape? All apes suffer from parasites. It would only make sense if humans lived in an environment where parasites were much worse - such as by rivers - for that to work. There has to be a reason for something to be sexually selected. Even in modern human history, there are reasons for what is considered beautiful. Pale skin used to be extremely desired in many cultures up until recently because it showed off a woman’s status, and the fact that she had the luxury of not getting tan through working in the feilds. There are reasons for things to be sexually selected. It seems to me that many scientist - amatuer and professional - rely on the blanket term ‘it must be a sexually selected feature’ for something they really can’t see the purpose of. Of course, things like peacock’s tails really are sexually selected. But I don’t think hairlessness would fall into this category, unless there were other strong reasons accompanying it, because then why don’t apes also have a tendency to sexually select less fur?

I don’t think AAT/H has any gaping holes - minor ones, yes, such as the idea that there was a distict aquatic phase, etc…, but gaping ones, no. I also find that many of the arguments against it are extremely flimsy, or they take the idea to the extreme, or they ‘disprove’ a point by falling back on the same analogies that they hate so much or by providing analogies that don’t really apply yet make them seem as if they do apply. I also think that all the other theories are at least as flawed, or even more so, than the AAH. However, as you clearly disagree with me, and have stated by you do so, let’s let this one drop and not get into a spitting match over it.

No, I did not necessarily word the theories inaccurately, although I didn’t describe them the same way that textbooks etc.. that favor them do. Regardless of whether apes reliably stand up for food getting, it still does not explain why that would provide enough pressure for human ancestors to become bipedal. And the majority of wading time for non human primates is not quadrupedal, it’s bipedal. Where on earth did you get that idea from?

That was long again. Sorry about that.

We find that chimps just don’t have the huge problem with predators that we might think they would, and they don’t handle predators simply by running away or climbing. Predators mostly avoid them, and the predation they suffer is too little to have kept them from prospering for millions of years. There is no reason to assume that our ancestors couldn’t do what chimps do vis a vis predators.

However, your assumption that terrestrial predators are not seen by chimps doesn’t seem to be how the real world operates. Sometimes sure, but mostly no.

The claim that Afar crocodiles are special friendly non-hominid eating crocs is something started by Morgan, and it founders on several points. First, there is no reason to try to posit that there was an aquatic period centered on Afar; even Morgan has dropped that apparently, and for good reason: we find earlier and earlier fossils in other places. Also, we’re not talking about which crocs now live there, but which crocs lived there in the past. We are also not talking about preying on modern humans (with modern weapons, even “modern” weapons like spears), but preying on our ancestors which is not the same thing (even so, crocodile attacks are numerous and dangerous for reasons I go over in detail on my site). Shark attacks would not, IMO, be as bad a problem, but would be in some areas. The biggest problem for both sharks and crocs, though, is that the attacking animal is generally not seen at all until it has bitten the victim, and then it’s too late. I’m afraid I don’t find the notion of crocodile-wrestling hominids to be anything other than ludicrous. Ditto for your argument that humans are pretty much like dolphins — really, come on…

Also note that today (besides shark fences on many swimming beaches) only a small part of our population is in the water, whereas the AAT/H insists that the entire population used water every day for massive amounts of time — otherwise there’s no selection pressure for these massive changes.

Oh, and about the hair and skin. What we have may be inefficiant when compared to true aquatics, such as dolphins or seals, but compared to apes? Our relative hairlessness would be far more efficient in the water than their pelts. Besides, you’re missing the point. If even a little hair shaved off makes us more efficient in the water, then how much difference must hairloss have made to an ape?

The point it that we have just exactly what swimmers don’t want. We could have no hair and that’s better; we could have lots of hair (like most aquatic mammals) and that would be better. Both those possibilities fit the evidence from sports science. But instead the AAT/H proponent is forced to argue that millions of years of evolution devoted to swimming and diving has left it’s mark on our hair patterns, and done so by leaving us with exactly what we don’t want. That doesn’t make sense. And out hair patterns are rather obviously the result of sexual selection, which is of course another mark against the notion that it’s due to environmental determinism.

I’m afraid the notion that the AAT/H doesn’t have any major flaws is just silly. It has many major, and very bad, flaws.

THerefore, what’s wrong about shifting the purpose of fat within the theory to suit new evidence?

Well, to start with, the fact that the “new” purpose doesn’t fit the facts either.

THe theory that apes stood up to better reach fruit is ludicrous, because apes climb trees. Yet apparantly that theory is more scientific that AAH/T. THe theory that apes stood up to see over grass is also implausable, because they would simply return to all fours when they were done looking, if that were the case. I don’t feel like listing all of them right now, but in all of them the disadvantages about becoming bipedal outway the advantages, and they are still more accepted by mainstream scientists than AAH/T.

These ideas do make sense, although you’ve worded them inaccurately. They not only make sense because that’s when we see other primates using bipedality, but they’ve been tested. Actually, the most common, and long-lasting, use of bipedality is food-getting and carrying. But displays and observation are also very common uses of bipedality. The idea that wading is a major time when bipedality was used is interesting but doesn’t hold up; other than unusual times when wading in very deep water without swimming, what we see mostly is wading while doing food-getting and carrying… so is the wading really the reason, since it’s what they do on land so often too? And the majority of wading time for non-human primates is quadrupedal.

no, I’m not trying to be petty, but the moment you start criticizing me as a person (and yes, you were doing so) goes far beyond having a fun and interesting debate. If you think I am wrong, then say why I am wrong, with facts and reasons, do not start attacking me and calling me illogical.

By the way, I was not ‘exploring unbound conjecture’. Much of what I was saying has facts and reasons behind it. However, since this was merely an interesting debate on the internet, I didn’t bother to site any sources. And of course neither did you. However, if you want me to trace everything I was saying back to a source, then I will.

I am going to make myself very clear. Debates, whether online or in person, are only fun when both sides respect one another. Now, I do disagree with the points you make, and have said why I do so, but I also respect your opinion and can understand why you think the way that you do. Clearly that same respect is not afforded to me, if you have to belittle me and write at me in a condescending manner. (although I did the same to you in this post, thought it was a reaction)

Please, if you feel that I am being illogical, list every point and say in black and white why you think it is illogical. I do the same when I find something to be illogical. But saying in general that my arguements are illogical, that AAT/H proponents arguements are bogus is not really respectful, nor does it make you come across in a positive light, if that’s what you have to resort to merely because you dislike a theory.

I will respond to your comments later, but with all due respect (this is not a slur), you are not really engaging in logic-based debate and argumentation, rather you appear to be overtly exploring unbound conjecture and trying to fit the data to the hypothesis, when clearly, it should be the other way around.

Also, the predator arguement agains AAH often relies on finding each and every vicious aquatic predator and having them all prey on the apes at once, while they founder in the water. But most aquatic predators that people list would not even apply to the AAH, and it is highly unlikely that even if they did, all the most vicious of these species would happen to exist in the same place that early humans were developing. SHarks, for instance, would not be a serious threat. The amount of shark attacks in shallow waters is very low, even in modern times when we have far more people than existed then. It is still highly unlikely to be attacked by sharks in the water. Even in diving comminuties, the chances of being attacked by sharks is very slim. When it does occur, however, the sharks can usually be deterred by punching or kicking them, which would imply that sharks do indeed respond to threats. There also are documentations of dolphin groups intimidating sharks, which would render your claim, that marine predators do not respond to threats or intimidation or counter attacks, entirely false.

THe primary predator would be the crocodile. However, there is evidence that it would not be as terrible as it is played up to be. There are many species of crocodiles throughout the world, and in only a few areas are they serious man eaters, mainly in the Nile and the marine crocodiles of Australia. However, evidence shows that early humans lived by the Afar sea. The crocodiles in that region are not the man eaters of the Nile or Australia. They probably could be dealt with by humans/apes. Also, crocodiles and alligators jaws can easily be held closed. It is ludicrous to assume that these early humans/apes would not have known about this, yet would have known how to deal with lions.

ANd yes, terrestrial predators will often chase their prey into the water. However, an animal that can swim and dive will have the advantage in that situation, and would probably be able to get away, because they would be more efficient in the water than the terrestrial predator.

I don’t understand your point about shifting goal posts. All theories revise when new evidence is presented. THerefore, what’s wrong about shifting the purpose of fat within the theory to suit new evidence? That’s what’s done in every other theory of evolution, yet when the AAH/T does it, people imply that they are twisting facts, etc… You can’t have it both ways. Such double standards should not exist in science. The same goes for the theory itself. THe AAT/H has been subject to extreme scrutiny, and not one all encompasing flaw has been found, and it still hasn’t been accepted by mainstream science. Yet other evolutionary theories have far more holes in them and are not subject to the same scrutiny. THe theory that apes stood up to better reach fruit is ludicrous, because apes climb trees. Yet apparantly that theory is more scientific that AAH/T. THe theory that apes stood up to see over grass is also implausable, because they would simply return to all fours when they were done looking, if that were the case. I don’t feel like listing all of them right now, but in all of them the disadvantages about becoming bipedal outway the advantages, and they are still more accepted by mainstream scientists than AAH/T. Why does this double standard exist? ANd it’s not because AAH/T is not scientific, because it has far more evidence behind it than many of the other theories. IT even has fossil evidence - many of the early fossils have been found by lakes or in wooded areas that would imply the existence of a close water source, which directly ties in with the AAT/H.

First is on the subject of aquatic vs terrestrial predators: one of the bigger problems with the AAT/H claim that predators aren’t a problem for the idea is that unless you’re suggesting an exclusively aquatic species (which no one even halfway sensible is suggesting) they would have to face both types. All their arguments, bogus though they are, about terrestrial predators would apply to their scenario as well, plus the aquatic predators added in. The usual claim there is that the little beasties just run in and out of the water depending on what predator they are avoiding, but this founders for two reasons. One is that terrestrial predators will, and often do, chase their prey into water where their bounding abilities give them an even greater advantage compared to their prey; the other is that aquatic predators are generally not even seen or detected before the attack, while terrestrial predators often are.

The other point is on fat. We see that fat is generally adapted for two things, extra food and — often — body shaping. This body shaping can be sexually selected, as our life history shows it is in humans, or for a functional purpose like streamlining, as it is in whales and seals (the animals the AAT/H says we resemble in this feature, although they don’t like to name them because then it’s obviously ridiculous and the feature is not at all similar in life history). For whales and seals, their fat is adult-like at an early age (at birth for whales), as soon as they hit the water. For humans, we start off fat as babies, go through an extremely lean period as children (except for modern overfed kids), then get remarkably fatter right at puberty. If this was due to water use, whether for insulation or bouyancy, this would mean that babies were aquatic, children weren’t, then we become aquatic again exactly at puberty… and females would be more aquatic than males at puberty. The alternative explanations — unique-among-mammals fatness for our babies as part of our unique-among-mammals extended post-partum development, fat at puberty and variation between the sexes due to sexual selection — don’t have this tortured path to follow.