A New Twist on the Aquatic Ape Theory

[Marios]

You should ask anthrosciguy about that.

These threads haven't really shown the AAH at it's best. I don't think there's much point in going into counterfactual "Why do people have hair on their heads?" unless there's a competing theory which explains this where AAH does not.

Morgan's "AAH" (recent edition) was far more compelling in that it simply offered up a long list of human physiological oddities unexplained by other theories but explained by the AAH (footnoting the ones she's subsequently found to be wrong/lacking in substantive evidence).

It's triggered all sorts of rants - some slightly justified, some not - but there seems to be a big division between science-leaning anthropologists who see this as a challenge to come up with better hypotheses and humanity-leaning anthropologists who seem to be comfortable criticising it without comparison to any superior hypothesis (once you've pointed out three weaknesses in the hypothesis, you can chuck it in the bin and that's the end of the matter - noses don't need explaining or breath control or any of these things).

If the AAH is so very poor, lets see the superior competitor hypothesis.
Marios

[DavidMcC]

These threads haven't really shown the AAH at it's best. I don't think there's much point in going into counterfactual "Why do people have hair on their heads?" unless there's a competing theory which explains this where AAH does not.

I don't fully agree. Morgan made a point of explaining the hair issue by reference to possible use by a baby to hang on to in the water when mum had to swim away from a cat, say. This was attacked on the grounds that, although modern pregnant women's hair thickens, it also pulls out very easily at that time. I remember suggesting that this might be because of the millions of years since the aquatic period. I later mentioned the UV protection role.
I'm sorry if you think I'm not up to the job!
Edit: My attitude is to debate specific points, rather than to make it look as good as possible for the AAH.

[Marios]

I don't fully agree. Morgan made a point of explaining the hair issue by reference to possible use by a baby to hang on to in the water when mum had to swim away from a cat, say.

A cat? I remember her mentioning this - I don't know if she stresses it less in the more recent addition, but I took this a clear 'food for thought' comment - like saying that perhaps people like going to the beach because we had a long littoral period. It's not something she starts a chapter on, nor something her argument really stands on - just a vague suggestion for why head hair may have been retained.

This was attacked on the grounds that, although modern pregnant women's hair thickens, it also pulls out very easily at that time. I remember suggesting that this might be because of the millions of years since the aquatic period. I later mentioned the UV protection role.

Well, that's just plain old refled ad hoccery. You can't state a prediction - I believe that hair evolved as a mechanism for babies to hang onto - then just modify it to fit with previously contradictory data. That doesn't make you look good and undermines the rest of your argument (note - Morgan hasn't done this, her most recent book notes where some suggestions have in fact been shot down by contradictory evidence - sure, it's possible that she is still right and that some subsequent evolution process altered some characteristics - but that's not what she originally suggested, so the original hypothesis _must_ be clearly and publically abandoned).

If you the aquatic ape hypothesis has nothing to say about head hair - which seems to be the case - that's fine. One hypothesis does not have to predict everything (I think Morgan has been criticised for trying to explain too much with one idea). It's not a failure of a theory to explain some phenomena unless a rival theory does a better job.

I'm sorry if you think I'm not up to the job!

Well, I do think you're focusing on the elements of the hypothesis that I found least convincing and letting yourself get into silly arguments where the AAH has to justify every phenomena and battle fearsome hypothetical threats. If you go down that path, you play straight into the hands of people who claim that this isn't just a reasonable hypothesis but a point of dogma which Explains Everything.

Scientific theories and hypotheses are not supposed to be defended - by definition, you cannot! - they are positions from which you can effectively attack other theories. Science isn't about theories which are irrefutable - any theory can be made irrefutable by sufficient expenditure of effort and adhoccery - but about which theory can (i) make itself most vulnerable and (ii) survive longer than competitor theories.

Edit: My attitude is to debate specific points, rather than to make it look as good as possible for the AAH.

Probably better to stick to specific points of current human/chimpanzee physiology, rather than specific points of 6 million year old environments - I think that's outside the remit of specificity.

Points I'd like to see answered is what rival theories people prefer and why it is that they think they provide more explanatory power/testable hypotheses.

Marios

[DavidMcC]

Well, that's just plain old refled ad hoccery. You can't state a prediction - I believe that hair evolved as a mechanism for babies to hang onto - then just modify it to fit with previously contradictory data.

Frankly, I don't care if it looks bad. Ms Morgan, not unreasonably, regarded protection of the baby as very important in her hypothesis. All I want to do is find out by argument, what might be true and what can't be without allowing the AAH to be dismissed just because one point in favour turns out to be unclear. I didn't expect it to be easy, given that it has been millions of years since the period in question.
Edit: In case you're not clear about it, I suggested that weakening of the hair follicles might have been relatively recent to emphasise that one can't dismiss (or indeed confirm) the AAH entirely on the basis of a particular aspect of modern humans.

[Largenton]

Quick question. Would you compare the early hominid to the Hunter-Gatherers of today in that they hunted and gathered? I'm not trying to compare techniques, instead I just want to know if thats the lifestyle you would prescribe to them?

Note I said quick question, what I meant was yes or no, did they hunt and gather in the same way. Your explanation wasn't needed and was pretty much irrelevant. Remember KISS?

Would you briefly summarise (a paragraph or two) what you see as "Bailey's hypothesis"?

Certainly. Bailey advocates that the volcanic regions and the uplands of the Rift Valley provide a perfect habitat for humans. In this habitat they have safe havens, as shown by the Hamadryas Baboons who use the basalt enscarpments to sleep in safe havens at nights. It is also possible to use the terrain for hunting traps too, to prevent the animals from escaping, an excellent example of our ambush methods. The terrain also provides lakes, which I tie in the shellfish ideas and also tool making material and fire, two important things. Check the second page of this topic, I posted a link to the article.

I've lost track -- what idea of yours do you feel is valid because kids are able to be taught to swim (as they can be taught to do so many things -- unsurprising in an animal which is one of the world's great generalists)?

I'm not supporting my idea, I am merely stating it is possible for us to learn to swim efficiently, very easily. I don't like the savannah idea to be honest, its too, presumptious.

Tests of tooth enamel and C4. Here's a link to a news story about it from a while back (news story and a rather long blog entry which has that and other good info (blog entry). You'll have to scroll down quite a way -- over halfway down the page -- to get to the relevant part, sorry.

So let me get this straight, you are using C4 plants to claim this? Cos if I remember rightly, marine foods give off more C4 stuff than terrestrial plants........ Plus, is there a peer-reviewed article you could give instead?

[DavidMcC]

Morgan's "AAH" (recent edition) was far more compelling in that it simply offered up a long list of human physiological oddities unexplained by other theories but explained by the AAH (footnoting the ones she's subsequently found to be wrong/lacking in substantive evidence).

It was, of course, the wrong ones that gave the opposition so much ammunition with which to dismiss the AAH in the first place. They accused her of deliberately lying in the case of the supposed aquatic-type subcutaneous fat, for example.

[Marios]

Edit: In case you're not clear about it, I suggested that weakening of the hair follicles might have been relatively recent to emphasise that one can't dismiss (or indeed confirm) the AAH entirely on the basis of a particular aspect of modern humans.

That's rather the kind of statement which makes people with no understanding more confident and everyone else less confident. There's nothing wrong with linked hypotheses, so long as it's quite clear what form a falsification would take and, should some sub-hypotheses be falsified how much of the rest of the structure would go with it.

The evidence of hair follicle weakness in mothers falsifies the original hypothesis (that it evolved directly to support child carrying in water). Fair enough. If every prediction of the AAH distinct from rival theories was falsified (and the falsification was accepted), then it would die in favour of a theory which asserted something more that wasn't falsified.

I don't quite understand why you think babies being carried by hair is a central part of the AAH for Morgan - was this in "The Descent of Woman"? Did she write a book about children too? It certainly wasn't an impression I was left with from the most recent edition of the "AAH".

I don't think it really compares to bipedalism, breath control or brain growth. To be fair, a theory which was only able to describe _one_ of those three would be worth looking at.

Marios

[JeffLee]

(once you've pointed out three weaknesses in the hypothesis, you can chuck it in the bin and that's the end of the matter - noses don't need explaining or breath control or any of these things).

breathing control? i thought that didn't show up until after erectus...[i think it was Hewitt's work.] i remember it being used by a guy arguing that language was a recent evolution. isn't that abit outside the AAH time line?

[anthrosciguy]

Also, while Hardy and Morgan both claimed an early aquatic period, other proponents claim we've been semi-aquatic all through human evolution, despite the fossil evidence.

I see nothing has been said about the female sexual scent. Does this mean it is unique to humans?

All primates, and of course at least the vast majority of mammals (probably all), have sexual scents. Your notion seemed non-serious so I didn't say anything about it. If you were really serious then ask yourself why the scent you claim would be one that would be guaranteed to attract aquatic predators.

Also, if modern humans are the most amphibious of the hominids, wouldn't this make it less likely that we'd find fossils in lake bed strata? If your family lived around and fished in a lake for a really long period of time, you'd watch anybody capable of drowning -- the very young, the very old and the infirm -- pretty closely. There's a good chance that even if they did drown, the corpse wouldn't stay in the water for long because other members of the band would attempt a rescue. Were it any other way, nobody would have the courage to fish.

If an animal is living in and around a certain environment, we expect to see their fossils in and around that environment (as it was when they died, of course, not the environment in that area now). Animals which live in and around aquatic or shoreline environments tend to be fossilised at a terrific rate, and we'd expect to find an awful lot more hominid fossils than we do if they lived in that envionment.

I still haven't seen a good rebuttal to my comments about croc-killing. Instead I get general arguments along the lines of, "Oh, it's too dangerous, and besides, people would have exterminated them if they were that easy to kill." However as your posts have pointed out, crocodiles are quite prolific, and would have spread back to any lake where they'd been killed off after a few years. As to the danger, how is being killed by one animal any different than being killed by another? If modern "stone age" hominids are capable of killing healthy adult elephants -- something lions have a difficult time doing -- why would there be any problem killing crocs?

There are no modern "stone age" humans; that you claim there are indicates you know very little about human evolution or anthropology at all. You might be interested in learnign something about the subject -- it's very interesting.

In fact we find that crocs are very hard to kill, and the notion of hominids killing off all the crocs in a given area seems, frankly, nonsensical. As I mentioned, we weren't even able to do this with weapons that were terrifically advanced compared to those our early ancestors likely had, or even compared to those our ancestors had as late as 15,000 years ago. We were only able to do this once we got to the point where we had guns, very good spear tips, and the ability to do wholesale habitat destruction on a huge scale -- no more than a couple hundred years ago.

Finally, we keep going round and round about the fact that a submerged croc would be very dangerous. There has been no reply to my suggestion that the time to attack a crocodile is when it is torpid and basking on the beach, trying to warm up.

That people without herpetology degrees are capable of learning what exactly the dangers with crocodilians are in great detail is demonstrated by the late Steve Irwin, who was trained as a diesel mechanic, yet had enough confidence around these animals to hand feed one while holding his infant son in his other arm! For Irwin, that performance was mostly illusion since he knew that the crocodile he fed was close to exhaustion, and couldn't have charged him even if it wanted to. Jared Diamond characterized hunter-gatherers as having an almost encyclopedic knowledge of their environment. I doubt that this would exclude crocs!

I wasn't aware that the croc Irwin was feeding while holding his infant was close to exhaustion -- how did that happen, I wonder, in a small pen in a wildlife park? As for knowledge about their environment, I would expect hominids to have a great deal, including crocs and their dangers. That's why they almost certainly have stayed away from places crocs were in as much as possible.

[anthrosciguy]

Note - the hominids for which the evidence (criticised as questionable by John Hawks) for vegetarian tuber diet has been put forwards are 2 million years old. From what I remember of Morgan's hypothesis, that would be well post-aquatic.

Why are people whittering about crocodiles? I don't remember there being a single reference to crocodiles in the AAH. Do anthropologists favouring a savannah-mosaic hypothesis have to justify why we wouldn't have all been killed by savannah lions and tigers?

Marios

These are the teeth that have been studied. Because such study is destructive it isn't likely to be done on very rare very early specimens. However, we do see marks on teeth further back that are consistent with these studies, we find earlier fossils in the sorts of areas where this diet would be likely, and it seems very likely that this would be part of the diet of earlier hominids as well as those whose teeth were actually tested.

Yes, it's true that the AAT/H had, for 4 decades, no mention whatever of aquatic predators. This is not a strength of the theory (to be mild ) because any theory of human evolution has to deal with the predators of the areas talked about. After I pointed this out, Morgan finally did mention crocs -- she called them "hypothetical". The other proponents do either handwaving, magically making them disappear, or come up with nonsense scenarios like the one we see here from gwolf. I've got some pages on my site about predators, both terrestrial and aquatic, and describe how hominids likely dealt with terrestrial predators and why there's a big problem with the idea of dealing with aquatic predators. Rather than my repeating all that here (it's long), I'd suggest you read it there.

[anthrosciguy]

The problem with comparing humans with "typical" aquatic mammals is that you have to take into account the specific pre-adaptations in each case. No other aquatic mammals had universally jointed limbs, and therefore lost them. Our early attempts to swim (slow as they were relative to fully aquatic anmimals) would have been aided by universal joints, without which you are limited to paddling.
The hair probably had to stay on our heads even though it would have been a drag in water, to act as a UV protection in the absence of skin pigmentation (which apparently only appeared about 1.7MYa, as mentioned in a reference that Oolon Colluphid gave in the first aquatic ape thread). NB, UV protection on the head would have been very important, as the head is particularly vulnerable in that respect, and UV exposure in women can give rise to anencephalic babies!

If you leave that hair alone, as well as other human body hair, you don't have the swimming effiency argument anymore, at least not any accurate, meaningful argument. You also have to ignore the fact that, while it doesn't fit the swimming effiency idea, it's an exact fit to the idea of sexual selection (varying among peoples, varying between the sexes, changes radically right at puberty).

[anthrosciguy]

Morgan's "AAH" (recent edition) was far more compelling in that it simply offered up a long list of human physiological oddities unexplained by other theories but explained by the AAH (footnoting the ones she's subsequently found to be wrong/lacking in substantive evidence).

It's triggered all sorts of rants - some slightly justified, some not - but there seems to be a big division between science-leaning anthropologists who see this as a challenge to come up with better hypotheses and humanity-leaning anthropologists who seem to be comfortable criticising it without comparison to any superior hypothesis (once you've pointed out three weaknesses in the hypothesis, you can chuck it in the bin and that's the end of the matter - noses don't need explaining or breath control or any of these things).

I found Morgan's latest (the 1997 book you refer to) to be as accurate as her previous work, which is to say "not very". I have a page about that book on my site as well. And the few (pretty much one) spot(s) where she admits her idea was wrong she falsely claims it's found to be wrong due to new evidence not known until after she'd written her previous stuff even though the evidence was known well before she started her AAT/H writings in the early 1970s -- and in some cases the evidence (for instance re tears) was not only known when she wrote it up, it was in the same book she used as a source... and not even just the same book, but the same chapter, in fact on the same pages as info she used! That's not adequate scholarship for a term paper, much less an idea that's supposed to virtually overthrow all of paleoanthropology.

Even if you show another hypothesis is completely wrong in every regard, it doesn't strenghten the semi-aquatic one. The thing is, Morgan's "long list of human physiological oddities unexplained by other theories but explained by the AAH" are, first of all, almost all falsehoods. Things not actually similar to aquatic and semi-aquatic animals. Sometimes things also found in other priamtes, contrary to Morgan's claims. Sometimes things simply made up. So what you have is a bunch of things that, sure enough, other theories don't explain. They don't explain them because they are not true.

As for the two examples you mention, we know when the human-style nose developed, about 1.5-2 million years ago, not when Morgan claimed. We also know why, interestingly enough, because researchers are able to actually look at bone growth in fossils; it's a side effect of the foreshortening of the face and the brain size increase between australopithecine times and Homo erectus. The breath control is a side effect (a very handy one, it turned out) of bipedalism, because the forelimbs were no longer needed for locomotion and this freed up the muscles that control the diaphram.

If the AAH is so very poor, lets see the superior competitor hypothesis.
Marios

If you would like a suggestion of what I consider a superior hypothesis, I'd suggest my late wife's 1981 book On Becoming Human -- not only did it fit all the evidence known at the time, it still fits all the evidence found since (for instance, that robust australopithecines used tools, that females were likely the source of most early tool and tool use innovations, and others).

[anthrosciguy]

Quick question. Would you compare the early hominid to the Hunter-Gatherers of today in that they hunted and gathered? I'm not trying to compare techniques, instead I just want to know if thats the lifestyle you would prescribe to them?

Note I said quick question, what I meant was yes or no, did they hunt and gather in the same way. Your explanation wasn't needed and was pretty much irrelevant. Remember KISS?

Sure, the guys with the makeup. So what you're saying then is that you didn't want an actual accurate answer, which can't be just "yes" or "no". Forgive me, I had assumed you wanted an accurate answer; I stand corrected.

Would you briefly summarise (a paragraph or two) what you see as "Bailey's hypothesis"?

Certainly. Bailey advocates that the volcanic regions and the uplands of the Rift Valley provide a perfect habitat for humans. In this habitat they have safe havens, as shown by the Hamadryas Baboons who use the basalt enscarpments to sleep in safe havens at nights. It is also possible to use the terrain for hunting traps too, to prevent the animals from escaping, an excellent example of our ambush methods. The terrain also provides lakes, which I tie in the shellfish ideas and also tool making material and fire, two important things. Check the second page of this topic, I posted a link to the article.

It would seem that they are leaning toward (and you are falling headlong into) the problem of making human evolution an environmentally deterministic theory, which is a really bad idea for explaining the evolution of what is a supreme environmental generalist. That's why the actual theories of human evolution deal with social behavior and food-getting (part of what King and Bailey are doing in that paper is that as well, to their credit).

I've lost track -- what idea of yours do you feel is valid because kids are able to be taught to swim (as they can be taught to do so many things -- unsurprising in an animal which is one of the world's great generalists)?

I'm not supporting my idea, I am merely stating it is possible for us to learn to swim efficiently, very easily. I don't like the savannah idea to be honest, its too, presumptious.

See above re the actual theories put forth by paleoanthropologists as opposed to the claim by AAT/H proponents that anytime one mentions savannas and how we came to be able to live there as well as many other types of environments they are talking about environmental determinism as the AAT/H does.

Tests of tooth enamel and C4. Here's a link to a news story about it from a while back (news story and a rather long blog entry which has that and other good info (blog entry). You'll have to scroll down quite a way -- over halfway down the page -- to get to the relevant part, sorry.

So let me get this straight, you are using C4 plants to claim this? Cos if I remember rightly, marine foods give off more C4 stuff than terrestrial plants........ Plus, is there a peer-reviewed article you could give instead?

There are a number in the links I gave. Not just C4. Which has more? I don't know, but the preponderance of evidence from many sources of data is that these hominids were in terrestrial enivronment.

[gwolf]

All primates, and of course at least the vast majority of mammals (probably all), have sexual scents. Your notion seemed non-serious so I didn't say anything about it. If you were really serious then ask yourself why the scent you claim would be one that would be guaranteed to attract aquatic predators.

It is my own experience that the scent is restricted to human females, and then only to times of sexual excitement. That is why I asked if you knew of any other ape or primate that has this feature. If I am really serious, I ask why a savanna ape would evolve that particular smell. Wouldn't we expect a smell only slightly modified from that of other apes or primates? As to whether or not it would attract predators, I'd say that ANY smell would do the job. I think we're back to crocs, unless you know of another large aquatic or amphibious predator that lives in the rift lakes.

There are no modern "stone age" humans; that you claim there are indicates you know very little about human evolution or anthropology at all. You might be interested in learnign something about the subject -- it's very interesting.

I put "stone age" in quotes in my original post for a reason, since I am as aware as you that humanity has left both the Old and the New Stone Ages far behind, even in those places where animals are hunted without modern weapons. I meant to convey that modern weapons are NOT required to hunt dangerous game, viz the Clovis points found in the remains of North American mammoths -- animals that I presume to have been much smarter and more dangerous than crocodiles. I don't think that my argument was properly refuted by any means.

If an animal is living in and around a certain environment, we expect to see their fossils in and around that environment (as it was when they died, of course, not the environment in that area now). Animals which live in and around aquatic or shoreline environments tend to be fossilised at a terrific rate, and we'd expect to find an awful lot more hominid fossils than we do if they lived in that envionment.

I'd say that sounds almost like a truism. In fact, we'd expect to find the remains either in the places that the animals actually died, or where the remains ended up after having either sunk or been washed downstream. Archaeopteryx Lithographica appears in the Solnhofen slate not because it lived on muddy lakebottoms but because that is where it ended up after having dropped dead somewhere else. So if hominid remains aren't found in lake bottom sediments, all that really means is that they didn't die there or wind up in the water when they did die. Again I feel we are making no allowance at all for hominid group behavior or intelligence.

In fact we find that crocs are very hard to kill, and the notion of hominids killing off all the crocs in a given area seems, frankly, nonsensical. As I mentioned, we weren't even able to do this with weapons that were terrifically advanced compared to those our early ancestors likely had, or even compared to those our ancestors had as late as 15,000 years ago. We were only able to do this once we got to the point where we had guns, very good spear tips, and the ability to do wholesale habitat destruction on a huge scale -- no more than a couple hundred years ago.

This "very hard to kill" statement keeps getting repeated. I'd like to see evidence this time. We know that crocs are prolific enough to repopulate places in which they were killed off (else there'd be very few Nile Crocodiles left in Africa). We know they kill people who don't know any better than to wash clothes in a body of water inhabited by them. However, such people are not hunter-gatherers, and wouldn't have the knowledge of the critters that h/g people have. We further know that h/g people know enough about prey species not to over harvest them, and if the crocs were a source of food, they wouldn't have tried to kill anything that wasn't a threat and wouldn't be a meal that night. It would have made no sense!

I wasn't aware that the croc Irwin was feeding while holding his infant was close to exhaustion -- how did that happen, I wonder, in a small pen in a wildlife park? As for knowledge about their environment, I would expect hominids to have a great deal, including crocs and their dangers. That's why they almost certainly have stayed away from places crocs were in as much as possible.

When that zoo stunt showed up on TV, Irwin was charged with reckless endangerment. He was made to testify under oath about the condition of the animal he was feeding. The fact that "alligator wrestling" has such a long history among the Seminoles in Florida also says something about the trye "danger" of crocodilians.

[DavidMcC]

The evidence of hair follicle weakness in mothers falsifies the original hypothesis (that it evolved directly to support child carrying in water). Fair enough. If every prediction of the AAH distinct from rival theories was falsified (and the falsification was accepted), then it would die in favour of a theory which asserted something more that wasn't falsified.

The point I wanted to make was precisely that hair follicle weakness in modern women isn't a "killer" for the AAH explanation of that issue, although it obviously weakens it. In the absence of any other explanation, it would still stand. Having said that, it is possible that the UV protection afforded by head hair needed "beefing up" during pregnancy to avoid anencephalic babies in the savanna period. Nobody, to my knowledge, had said that.

I agree that Morgan didn't give the issue prominence in her books. This might be because she knew the problem it had. It was given more prominence in a TV program on the AAH, which involved Morgan. What is clear, however, is that she rated protection from predators higher than food gathering. In my own mind, I had to switch over to food gathering after a previous debate.

[DavidMcC]

breathing control? i thought that didn't show up until after erectus...[i think it was Hewitt's work.]

I think the word fine, as in "fine control", gets used in this context, and I wonder whether that allows for "basic" breathing control being a pre-adaptation that was improved on in the savanna period.

[DavidMcC]

If you leave that hair alone, as well as other human body hair, you don't have the swimming effiency argument anymore, at least not any accurate, meaningful argument. You also have to ignore the fact that, while it doesn't fit the swimming effiency idea, it's an exact fit to the idea of sexual selection (varying among peoples, varying between the sexes, changes radically right at puberty).

How do you square that with the fact that shaving and wearing a skull cap only adds 3% to swimming efficiency. My suspicion is that taking a chimp-like ape and shaving him/her would add significantly more to efficiency.
Obviously, geographical variation of hair came after the geographical spread of modern humans, so isn't relevant.

[Largenton]

It would seem that they are leaning toward (and you are falling headlong into) the problem of making human evolution an environmentally deterministic theory, which is a really bad idea for explaining the evolution of what is a supreme environmental generalist. That's why the actual theories of human evolution deal with social behavior and food-getting (part of what King and Bailey are doing in that paper is that as well, to their credit).

I also acknowledge that social factors are a part, if it wasn't for the case of the different splitting up of hunters and gatherers and the choice to eat fish, we wouldn't be doing these things. I had this argument today, during my photography seminar with my friend. However, what is certain is that it is more likely to prove the environmental effects on us than the social aspects. Thats the reason why we get environmentally deterministic. Both have a part to play tho, but most hypotheses can only prove the environmental aspect.

See above re the actual theories put forth by paleoanthropologists as opposed to the claim by AAT/H proponents that anytime one mentions savannas and how we came to be able to live there as well as many other types of environments they are talking about environmental determinism as the AAT/H does.

Actually, I was considering how the savannah theories seem very culture historical in interpretation. I enjoy the fact that people proposing different hypotheses means that they have to fight harder. Come on, you've got to admit that these ideas do challenge those beliefs and that they make scientists work harder at their data.

@ The articles thing, you only gave two, both of which weren't from peer-reviewed sources.

[anthrosciguy]

If you leave that hair alone, as well as other human body hair, you don't have the swimming effiency argument anymore, at least not any accurate, meaningful argument. You also have to ignore the fact that, while it doesn't fit the swimming effiency idea, it's an exact fit to the idea of sexual selection (varying among peoples, varying between the sexes, changes radically right at puberty).

How do you square that with the fact that shaving and wearing a skull cap only adds 3% to swimming efficiency. My suspicion is that taking a chimp-like ape and shaving him/her would add significantly more to efficiency.
Obviously, geographical variation of hair came after the geographical spread of modern humans, so isn't relevant.

Well, as for your last part, that's something I've repeatedly brought up with AAT/H proponents. Variation of hair seems to be controlled by very few genes and much of the variation in humans can be seen to be a recent thing (plus bearing all the classic hallmarks of sexual selection and not being due to environment). So there is no reasonable excuse for those proponents to claim it's either due to environment or an extremely old trait. Yet they do.

There's no reason to square the fact that human hair patterns bear all the classic hallmarks of sexual selection with the AAT/H environmental-cause claim; this is yet another example of theirs which simply doesn't fit the facts. My point was that AAT/H proponents claim our present hair patterns are due to selection for swimming efficiency yet they are exactly what swimmers interested in efficiency find do not work well.

[anthrosciguy]

However, what is certain is that it is more likely to prove the environmental effects on us than the social aspects. Thats the reason why we get environmentally deterministic. Both have a part to play tho, but most hypotheses can only prove the environmental aspect.

Claiming that perhaps the world's most supreme environmental generalist got that way via adaptation to a specific environment, as the AAT/H does, is silly.

See above re the actual theories put forth by paleoanthropologists as opposed to the claim by AAT/H proponents that anytime one mentions savannas and how we came to be able to live there as well as many other types of environments they are talking about environmental determinism as the AAT/H does.

Actually, I was considering how the savannah theories seem very culture historical in interpretation. I enjoy the fact that people proposing different hypotheses means that they have to fight harder. Come on, you've got to admit that these ideas do challenge those beliefs and that they make scientists work harder at their data.

@ The articles thing, you only gave two, both of which weren't from peer-reviewed sources.

John Hawks blog entries, which are quite thorough BTW, had several refs, as I said.

And again, you are using "savanna theories" as if that were a valid category. That just doesn't fit what paleoanthropologists have actually been doing for the past 35 plus years; they deal with social organization and food-getting, mentioning savannas as a place where we did learn to live (as the evidence shows we did).

[anthrosciguy]

There are no modern "stone age" humans; that you claim there are indicates you know very little about human evolution or anthropology at all. You might be interested in learnign something about the subject -- it's very interesting.

I put "stone age" in quotes in my original post for a reason, since I am as aware as you that humanity has left both the Old and the New Stone Ages far behind, even in those places where animals are hunted without modern weapons. I meant to convey that modern weapons are NOT required to hunt dangerous game, viz the Clovis points found in the remains of North American mammoths -- animals that I presume to have been much smarter and more dangerous than crocodiles. I don't think that my argument was properly refuted by any means.

Since we, in our non-modern days, did try to kill off crocs, along with virtually all other large predators, and were demonstrably unable to do so, even with vastly better weapons than our earliest ancestors had, suggesting they could do so is silly. For one thing, there wouldn't be crocs if they could do it.

If an animal is living in and around a certain environment, we expect to see their fossils in and around that environment (as it was when they died, of course, not the environment in that area now). Animals which live in and around aquatic or shoreline environments tend to be fossilised at a terrific rate, and we'd expect to find an awful lot more hominid fossils than we do if they lived in that envionment.

I'd say that sounds almost like a truism. In fact, we'd expect to find the remains either in the places that the animals actually died, or where the remains ended up after having either sunk or been washed downstream. Archaeopteryx Lithographica appears in the Solnhofen slate not because it lived on muddy lakebottoms but because that is where it ended up after having dropped dead somewhere else. So if hominid remains aren't found in lake bottom sediments, all that really means is that they didn't die there or wind up in the water when they did die. Again I feel we are making no allowance at all for hominid group behavior or intelligence.

Taphonomy is the study of how things fossilize, where they do, and how to tell something about numbers from the number of fossils we find. For instance, very small mammals tend to underrepresented in the fossil record because their bones get crushed too easily. Animals which live in water or along shorelines tend to be overrepresented because they live in places where they are likely to get fossilized. You are here forced to argue that hominids which virtually certainly didn't bury their dead or do much about them (rather like chimps) lived by water but nevertheless almost never died there. Sort of like having a Secret Hominid Graveyard, which is as likely as the elephant one of fable.

On crocs being hard to kill, it's hard to believe you're serious, but:
1989 Crocodiles and Alligators Various editors and contributors: Consulting Editor, Charles A. Ross (Museum Specialist, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, D.C., USA) Facts on File: New York and Oxford. "Crocodilians and Humans: Attacks on Humans". Chapter by A.C. (Tony) Pooley (Consultant on Crocodile Farming, Conservation, and Education, Scottburgh, South Africa), Tommy C. Hines (Consultant on Alligator and Crocodile Management, Florida, USA), and John Shield (Veterinarian, Cairns, Australia), pp. 176-177:
"However, the accounts of fatal attacks by large Nile Crocodiles -- 23 of the 43 attacks investigated -- indicate that these crocodiles were extremely aggressive and ferocious. There were several instances where crocodiles, having seized their victim, were either repeatedly stabbed with spears or knives, beaten with sticks, pelted with stones, or had sticks rammed down their gullets in order to prise the human victims from their jaws...but to no avail."

The fact that "alligator wrestling" has such a long history among the Seminoles in Florida also says something about the trye "danger" of crocodilians.

Now you're using a modern tourist-attracting activity to... never mind, that's really over the top. You've just jumped the shark.

[gwolf]

Since we, in our non-modern days, did try to kill off crocs, along with virtually all other large predators, and were demonstrably unable to do so, even with vastly better weapons than our earliest ancestors had, suggesting they could do so is silly. For one thing, there wouldn't be crocs if they could do it.

I find this a most extraordinary claim. Do you have inscriptions from our non-modern days indicating this? Or are you talking about more recent aborted attempts at killing off crocodilians after the invention of firearms? Remember, crocodilians were becoming seriously endangered because of their commercial value, and had not their hunting been seriously reduced, we would only be seeing them in zoos today.

As I understand it, if a local animal was on the menu, the local h/g's learned the hard way not to over hunt it. There are obviously cases where that happened, as in the case of the various kinds of big furry elephants that now no longer wander around North America and Eurasia. However, there are some differences between the extinct elephants and the non-extinct crocodilians. The former -- like humans -- tend to breed one at a time for quality, investing all kinds of time in the offspring. Any loss is therefore significant, Crocodilians breed instead for quantity. Their investment of parental care is present but much more limited. Losses among the young are therefore less significant, and quickly made up should the opportunity arise. So for this reason and the controlled hunting, Crocodylus niloticus and Alligator mississippiensis are back, and in a big way.

My comments about "alligator wrestling" were dismissed derisively. However, it has it roots among the Florida Seminoles, who were h/g's once upon a time. The idea was to capture and truss a live alligator then take it back to the settlement. That way the meat would be fresh when it came time to eat. One person could handle up to a ten foot alligator, first teasing it into exhaustion, then grabbing it by its tail, working up the body, and finally taking advantage of the fact that although alligators have a powerful bite, the jaw-opening muscles are weak. Once the jaws were tied shut, the completely exhausted animal was defenseless. Commercial "Gator wrestlin'" businesses have to rotate the animals they use because it really stresses them out. Here is what one herpetologist had to say about it. The techniques used on nature shows to capture even larger crocodiles come from these same Seminoles. As has been demonstrated on some of the nature shows, four men can truss up even an 18 footer with rope as the only tool needed. I think as a result that the skills of African h/g's to take crocodiles as prey are sadly underestimated. My criticism of anthrosciguy's source is that it merely restates that crocodiles regularly take human prey. It is true, but beside the point!

Taphonomy is the study of how things fossilize, where they do, and how to tell something about numbers from the number of fossils we find. For instance, very small mammals tend to underrepresented in the fossil record because their bones get crushed too easily. Animals which live in water or along shorelines tend to be overrepresented because they live in places where they are likely to get fossilized. You are here forced to argue that hominids which virtually certainly didn't bury their dead or do much about them (rather like chimps) lived by water but nevertheless almost never died there. Sort of like having a Secret Hominid Graveyard, which is as likely as the elephant one of fable.

I'm afraid this still doesn't take into account human intelligence in avoiding "trap" situations that would make fossilization easier. People familiar with their environment don't get mired in mud or quicksand, don't get taken as prey that easily or often, will be moved by would-be rescuers from some situations -- including watery ones, and (unlike elephants) may in fact be purposely buried. Remember, my argument is that it is h. sapiens, not earlier hominids that is the most amphibious. I should further point out that taphonomy seems to successfully predict that hominids in their lakeside environment would fossilize much more readily than pongids. In fact that appears to be the case. We don't have that many hominid fossils. However we have almost no "ancient" or "pre-pongid" fossils at all because chimps are a forest rather than an amphibious animal!

George Wolf

[anthrosciguy]

Since we, in our non-modern days, did try to kill off crocs, along with virtually all other large predators, and were demonstrably unable to do so, even with vastly better weapons than our earliest ancestors had, suggesting they could do so is silly. For one thing, there wouldn't be crocs if they could do it.

I find this a most extraordinary claim. Do you have inscriptions from our non-modern days indicating this? Or are you talking about more recent aborted attempts at killing off crocodilians after the invention of firearms? Remember, crocodilians were becoming seriously endangered because of their commercial value, and had not their hunting been seriously reduced, we would only be seeing them in zoos today.

I am talking about the fact that crocs weren't in any danger of being hunted out until we:
A) had vastly better weapons, including guns, with which to hunt them, and
B) were able to do major habitat destruction

I really think this was pretty clear before.

My comments about "alligator wrestling" were dismissed derisively.

Frankly, that's all it deserves. Even if you are claiming that this activity, done by modern Homo sapiens sapiens with modern items not available to our early ancestors, could somehow be done by australopithecines, you still end up arguing that:

A) our early ancestors removed all crocs from their habitats, yet
B) crocs were still there

Then you claim that:
A) they left some around, but
B) they got rid of them all.

Taphonomy is the study of how things fossilize, where they do, and how to tell something about numbers from the number of fossils we find. For instance, very small mammals tend to underrepresented in the fossil record because their bones get crushed too easily. Animals which live in water or along shorelines tend to be overrepresented because they live in places where they are likely to get fossilized. You are here forced to argue that hominids which virtually certainly didn't bury their dead or do much about them (rather like chimps) lived by water but nevertheless almost never died there. Sort of like having a Secret Hominid Graveyard, which is as likely as the elephant one of fable.

I'm afraid this still doesn't take into account human intelligence in avoiding "trap" situations that would make fossilization easier. People familiar with their environment don't get mired in mud or quicksand, don't get taken as prey that easily or often, will be moved by would-be rescuers from some situations -- including watery ones, and (unlike elephants) may in fact be purposely buried. Remember, my argument is that it is h. sapiens, not earlier hominids that is the most amphibious. I should further point out that taphonomy seems to successfully predict that hominids in their lakeside environment would fossilize much more readily than pongids. In fact that appears to be the case. We don't have that many hominid fossils. However we have almost no "ancient" or "pre-pongid" fossils at all because chimps are a forest rather than an amphibious animal!

Certainly no one can deny that Homo sapiens uses water and water resources more than our earliest ancestors (except for many AAT/H proponents such as Morgan). But that's because we use virtually every environment in the world; we are obviously environmental generalists, perhaps the best in the world, and claiming we do this by adapting to a specific environment just doesn't make sense. And no sensible definition of "amphibious", "aquatic", or "semi-aquatic" fits Homo sapiens. You are claiming that taphonomy suggests that hominids would be found in the numbers they are, yet we find that this doesn't fit the facts. You are correct about the reason apes don't appear that often in the fossil record, but the rest of it is ad hoc hand-waving and really doesn't help your argument.

[Combine_Dave]

If modern "stone age" hominids are capable of killing healthy adult elephants -- something lions have a difficult time doing -- why would there be any problem killing crocs?

Finally, we keep going round and round about the fact that a submerged croc would be very dangerous. There has been no reply to my suggestion that the time to attack a crocodile is when it is torpid and basking on the beach, trying to warm up.

I take it you have never met a crocodile. They are faster than us in the water and they can attack with great speed on land (albeit at only 10kph over distance).

So while they would have consumed any early human that entered the water, they would also have been extremely difficult (next to impossible)to kill on land.

Unlike those elephants you referred to, the hide of a crocodile really is impervious to pointed sticks and stones. On an African animal documentary I saw recently a pride of lions attacked a crocodile in an open field. The crocodile left unharmed, even though just one of the lions would have been around the same size as it...

[DavidMcC]

There has been no reply to my suggestion that the time to attack a crocodile is when it is torpid and basking on the beach, trying to warm up.

I think you might have missed this bit, Dave.
Not only would the basking period give hominids a chance to attack crocs, it would also give them a chance to get other food safely.