Notes on BBC Radio 4 program
"Scars of Evolution"
by David Attenborough
2-parter broadcast 12 and 19 April 2005
Notes on the first half hour of David Attenborough's "Scars of Evolution" radio show on BBC Radio 4, broadcast Tuesday, 12 April 2005
Attenborough starts off his introduction by talking about long distance swimmers, whose feats are certainly remarkable, but he does somehow neglect to point out that these are highly trained athletes who perform feats that ordinary humans do not, and cannot, do.
He then segues into running, leaving off any talk of athletes this time, but mentions that "our top speed is somewhat less than a rabbit" but doesn't provide any equivalent comparison for swimming speed; he just says "but we can swim".
We certainly can, but why dodge the comparison for swimming speed when it was apparently so important for running speed?
The answer is, of course, because our swimming speed -- even for the top athletes over a very short distance -- is abysmally slow.
While the best runners can do a mile at about 15 1/2 miles per hour, the very best Olympic swimmers can't even manage to do 6 miles per hour for 3% of that distance.
This is pitifully slower than most swimming animals, and it's frankly not all that impressive that the fastest athletes in the world, in the shortest sprint event, can nearly be matched by a fast walker -- a little over 5 mph.
To make this difference clear, when I was in my twenties I used to walk 20 miles in 4 hours, and I was not an athlete.
So I could walk for 20 miles at nearly the speed that the very best Olympic swimmers can only manage for a very short distance.
Attenborough continues the swimming theme with "and dive underwater, to considerable depths, holding our breath for upwards of [through ?] 6, 7, 8 minutes".
Again, these are very highly trained people, not anywhere near the norm.
Why not use the norm?
Perhaps because he'd be forced to acknowledge that untrained humans can be outdone in breathholding by untrained dogs, and that doesn't sound all that impressive either.
Having set the stage, Attenborough goes on to sound bites from a select few speakers.
In doing so he sets up several false dichotomies and begins setting up an impressive-looking strawman.
In fact, much of this first half hour is spent doing that, with the rest being portraying Morgan and Hardy et al. as victims of a blind, irrational, scientific establishment intent on protecting their territory rather than finding out stuff.
This is something you see done a lot in accounts of the AAT/H, and especially when Morgan is involved.
It plays well.
He begins in what seems an innocuous manner, with senior anthropologist Philip Tobias saying "Let's just talk about water and human evolution".
That's mild, and perfectly reasonable, but the cute little trick here is that this implies that paleoanthropology has not talked about "water and human evolution".
Does Tobias not know this, or was he just edited to suit?
I don't know, but judging from other statements Tobias has made (and makes later in this program) I suspect he just doesn't know.
This may sound odd, but anthropology is very fragmented and Tobias, as a "bones and stones guy", doesn't necessarily keep up with the rest of anthro theory.
He should before spouting off on it, of course, but not everyone wants to do that work on top on their own specialty -- it isn't easy, after all.
We're at about the 6:00 minute mark now, as anthropologist Leslie Aiello is heard saying "what Dart could be said to have done is to establish the savanna hypothesis".
The idea of the "savanna hypothesis" is important in discussions of the AAT/H because it's the method by which AAT/H proponents inaccurately claim that paleoanthropologists use the same sort of environmental determinism that they use.
Attenborough then goes on for several minutes about "Ardrey and others", "Naked ape", "Killer ape", "Mighty hunters", etc., laying the groundwork for making the claim that "even 40 years later it's still the basic account of early humans most commonly told in schools it gradually became apparent through the 80s and 90s that the story was a bit oversimplified. We didn't head out from the forest and make a completely new life on the open plains, and we didn't make a simple switch from grazing on fruit to chasing down big game and eating their meat."
Kind of a shame that he completely ignored the work of the influential women in anthropology who changed this way of thinking.
Starting with Thelma Rowell, and to some extent Jane Goodall, in the mid-1960s, and with an able assist from Richard Lee (who's male but has that "annoying" habit of doing good accurate work regarding male and female roles in society), and on through Sally Linton (nee Slocum) in the late sixties, then on through Nancy Tanner, Adrienne Zihlman in the 1970s, these ideas about males and hunting being at the root of hominid change were changed.
But note that these were ideas about behavior and food getting and social interaction, not about environment per se.
But even then the talk was of a mosaic savanna woodland -- although many people think of savanna as meaning a treeless plain, and Morgan and other AAT/H proponents have encouraged this belief, anthropologists know differently.
Check out my short page on the definition of savanna for clarification.
Attenborough either doesn't know this or doesn't want to mention it, and if he got his cue from Morgan (as seems likely) this is not surprising, because Morgan has consistently ignored these contributions by women.
(For a professed feminist this is really, well frankly, disgusting.)
Well, now Attenborough works it a bit to try to portray Tobias as being at the forefront of looking at environment (ignoring more women, by the way, like Elizabeth Vrba and A. Kay Behrensmeyer) and changes history by ignoring the work they did in the 1970s and letting his (Attenborough's) statement that "but by 1995 the doubts were overwhelming" make it seem that the mosaic of woodland, forest, and mixed savanna was new info then.
This allows him to portray Tobias heroically proclaiming claiming that "the savanna hypothesis is no more -- open that window and throw it out!"
At which point those in the paleoanthropological community who had been paying attention for the past quarter century looked at each other and said "the WHAT?"
Attenborough then plays a clip of Tobias saying "of course if savanna is eliminated as a primary cause or selective advantage of going on two legs then we are back to square one".
This reveals two basic, and rather sad, problems -- it demonstrates that Tobias incorrectly thinks that paleoanthropological theories were environmentally deterministic and it shows that he just wasn't familiar with the work done in that area for some 25 years.
Of course it wasn't his specialty -- but you'd think he'd have paid a little attention to it.
You see the actual theories of human evolution, being based on things like food-getting and social interaction rather than being environmentally deterministic, don't have to "start at square one" every time new information about habitat comes around.
Attenborough, however, buys the "square one" claim, but says that luckily, there's an alternative: the AAT/H.
This idea, he says, explains various human characteristics, for instance: "our bipedal locomotion on two legs" (as opposed to some other kind of bipedal locomotion, I suppose), "strange hairlessness", "layer of fat just beneath the skin", "big brain and unique language skills", and "the curious paradox that noses are very large but our sense of smell is comparatively poor".
With nearly 20 minutes left in the broadcast surely we'll hear the evidence for these claims.
For now we have to be content with some more building of the myth of the close-minded establishment -- he even uses the word "establishment" to make sure we get the picture: "but in establishment circles the alternative explanation was regarded as too bizarre and too radically different from the accepted savanna story to be taken seriously."
"But why was it regarded as bizarre pseudoscience and why did mainstream hostility continue for nearly forty years?"
Now we have the formal introduction of Elaine Morgan, who Attenborough says in 1967 was "a young woman from the Welsh valleys" (10 or 20 years ago I would've probably quibbled about a 38-year old being described as "young" but that's what getting older does to you. :)
And through her, Hardy's original idea, which was initially inspired by noticing the "peculiar layer of fat tightly bonded to the skin that humans have and other primates lack".
Never mind that the foremost researcher on the evolutionary significance of fat, Caroline Pond, has noted that this layer is also seen in any primate which essentially overeats as humans have been able to do for so long.
Never mind, of course, because noting that fact makes it seem less "peculiar" and more "of course".
According to Morgan, after Hardy gave his talk at the sub-aqua club, prominent anthropologist Le Gros Clarke called Hardy and "Alister, never do that again".
(According to some, Le Gros Clarke then went on to alert the entire worldwide anthro community to stonewall poor Alister and his idea, and of course they all clicked their heels together and said "javol!" -- Morgan and Attenborough, to their credit, do not indulge in this fairy tale image of a cohesive anthro conspiracy.)
Not that Attenborough doesn't indulge in some storytelling.
It's part of his ongoing attempt in this section of the broadcast to develop the idea of the blind, irrational, scientific establishment.
Morgan's claim that Hardy's idea was not accepted because of his not being an insider comes next.
"He was an outsider to the extent that his field was marine biology and not anthropology so they held that against him as well."
Attenborough then invokes the spectre of censorship (by the great anthro conspiracy, apparently):
"One might think it odd that an eminent marine biologist and fellow of the Royal Society would be barred
as an outsider from venturing some observations about human evolution..."
Apparently not having your poorly thought out and supported idea immediately accepted is equivalent to being "barred".
This is his intro to painting Morgan as even more of an outsider, as he continues "... but academic boundaries can be fiercely patrolled, and if Hardy was regarded as beyond the pale what of Elaine Morgan."
Ooh, just think what the GAC (Great Anthro Conspiracy) would do to her...
So for Attenborough's account, the anthropologists' lack of enthusiasm (which apparently is equivalent to "barring" someone from "venturing some observations") certainly couldn't be because Hardy's idea didn't make sense and used bogus "facts" -- no, of course not.
Attenborough then does some more positioning of Morgan as an outsider so he can say that "professional anthropologists liked the idea of the aquatic ape theory even less coming from Elaine Morgan than they had when it came from Sir Alister Hardy".
Well, it certainly was heard more; was it actually liked less?
No matter to Attenborough's account, actually; he's not really interested in the reaction except as a way to help in his
building of the myth of the closed-ranks to the outsider assailing the ivory tower etc... which is, by the way, a staple of Morgan's writing.
Attenborough again: "It didn't matter that she had researched the subject in great depth" and "if anything, the accumulation of further detail that she had painstakingly carried out made the anthropologists dig their heels in all the more firmly". Not, of course, because the idea didn't make sense and used bogus "facts" and misunderstandings of evolutionary theory, and misquoted people, and on and on -- no, no, no, of course not.
Morgan says of her first book, "the scientific reaction was bitter anger and contempt"
Maybe from where she sat; what I saw was more in the category of "amused", but of course that would be an annoying reaction to a person who's claiming to have a grand new theory that will overthrow the whole of a branch of science.
Attenborough now brings in some others to bolster his idea that Morgan and the AAT/H are beleaguered outsiders beset by irrational close-minded anthropologists.
In fact, Daniel Dennett actually refers to the "irrational hostility she engenders", which leads me to a question:
since she uses false facts and misunderstandings of evolutionary theory to support her hypothesis, is it irrational to oppose it, or is it sensible to do so?
Dennett that says there hasn't been "the right sort of measured and sober response; at least if there has been I haven't been able to find it".
Well, I'd have to say that Dennett didn't look too hard -- try a Google search, Dan :)
But then maybe my site, or Adrienne Zihlman's articles, or the articles in the book The Aquatic Ape: Fact or Fiction?, aren't "the right sort".
Oh well, we can't all have the right stuff.
Attenborough's back with more myth-building, suggesting that it's just because they were outsiders the idea provoked not just caution but "something more visceral, even jealousy".
That's it, they were all just jealous.
Look, I know many people, most people actually, haven't been inside academia or near enough to see the workings, but this is a ludicrous idea of how it all works.
Frankly, if people like an idea they just grab unto it and say a bit more about it, and then they're in the club too.
Happens all the time; in fact, you see it with the reaction to my late wife's work, where the stuff she and Zihlman did was adopted pretty much whole hog by a couple of guys, Glynn Isaac and later Owen Lovejoy, who added some (not too well-founded) additions, and got a lot of mileage out of it.
If people thought that Morgan and Hardy made sense they would've grabbed unto it so fast it'd have made Morgan's head spin like a top.
But to Attenborough the only possible explanation can be irrationality and jealousy, not of course because the idea didn't make sense and used bogus "facts" and misunderstandings of evolutionary theory, and misquoted people, and on and on -- no, no, no, a thousand times no, of course not.
He brings Graham Richards on to help him out; he agrees it was pretty much just jealousy, or maybe that "if it was true one of us would have come up with it first" -- the scary thing is that when people think others think like that, it's often because they themselves think like that -- and that anthropologists said dismissively "Oh she's cobbled together a kind of collage of different facts and figures".
Richards points out that a "key thing of a good scientific theory that it does this linking job on a lot of phenomena that were hitherto thought to be totally unrelated", but somehow neglects the equally important part, that those links and phenomena and facts and figures really need to be accurate instead of false.
Attenborough goes on to say that in her other 4 books she started "providing notes, referencing every citation" which is very nearly true for her last book on the subject, and she did better on her 1990 book.
Before that she really didn't, and you can read my overview of her 1997 book to see how many errors and false claims she did even in that, arguably her best referenced and supported book.
Still, better than nothing.
Uh oh, it's 25 minutes in and time for the Wegener comparison.
I have a page on Wegener and the way he's used by Morgan (and many others) as a comparison, and I explain how she, like others, describes his work and the reaction to it inaccurately.
This all shows up here again, with a bit of a extra touch.
The standard, and inaccurate, part is when Attenborough describes Wegener as a meteorologist who was therefore the "classic outsider" (he was trained initially in astronomy and did work in meteorology and is generally referred to as a geophysicist ) and says he was "roundly ridiculed and rejected by geologists for over 30 years" until "Wegener's plate tectonics became the accepted paradigm".
Well, as I explain on my Wegener page, he was supported by many and opposed by others, rather than "roundly ridiculed", but more importantly, it wasn't "Wegener's plate tectonics".
Plate tectonics is a mechanism, and that was the whole problem with Wegener's idea -- he had no mechanism that came remotely close to explaining how the continental movement he proposed could actually happen.
It wasn't until the 1950s and new equipment that could examine the ocean floors that a mechanism -- plate tectonics -- was found.
Plate tectonics was not Wegener's by any stretch of the imagination -- continental drift was -- plate tectonics wasn't.
This is an important distinction because here Attenborough is using a rhetorical trick, either because he's ignorant or he's deliberately trying to make a connection in people's minds to make Wegener's opponents seem, well, irrational, just as he's trying to make Hardy and Morgan's opponents seem irrational.
He does this by ignoring the fact that Wegener's idea of continental drift didn't make scientific sense without a mechanism and that Wegener had nothing whatever to do with the mechanism (plate tectonics) that was eventually discovered.
And as I stated on my Wegener page, the theoretical difference between the AAT/H and more conventional theories of human evolution isn't in what happened (hominids evolving from an hominoid ancestor), but in the mechanism for it. The mechanism (an aquatic past) is the different special thing the AAT/H brings to the table. and, just like the mechanism in Wegener's theory, it falls flat.
Then Attenborough makes the connection explicit as he switches to describing the supposed reaction to the AAT/H, using phrases like: closed ranks, ignored it, denounced it as bizarre, there's no testable evidence, and the ultimate "no equivalent to the spreading sea floor".
Poor Morgan is Wegener, you see, all who oppose her are blind supplicants to the ivory tower.
But, you see,: when the "evidence" used to support it is largely false, some people may consider this important.
Not Attenborough, apparently, but some people.
"Missing evidence is finally appearing" next episode apparently; about time; over 26 minutes into the half hour and you couldn't come up with any yet?
Ah well, we're told "meanwhile the mainstream anthropologists' view of where humans really grew up appears to be moving, hesitantly, down to the seashores".
We've always known that somewhere along the line, some water resources were used, just as we moved into many different environments; the only people who dispute that this was widely accepted are AAT/H proponents.
This, however, is not the AAT/H.
He does have Leslie Aiello saying a very important thing here, which he cuts off with an edit, "it depends what you mean by semi-aquatic; do you mean one toe in the water or..." .[and she's cut off].
This now is one of the longest running and biggest flaws in every version of the AAT/H; no one wants to explain what "aquatic" or "semi-aquatic" mean.
And when do they try they get very vague, unlike when scientists do the same thing, and then they have trouble explaining how we evolved features they say are similar to certain, usually vaguely referred to aquatic creatures (who turn out to be whales, seals, and sirenia) when we supposedly were just strolling along shorelines and such.
The first half hour closes with Elaine Morgan herself comparing her and Hardy's plight to Wegener.
Notes on the second half hour of David Attenborough's "Scars of Evolution" radio show on BBC Radio 4, broadcast Tuesday, 19 April 2005
Okay, this is good.
The first half hour had, really, no evidence whatever -- just claims of victimization of poor Hardy and Morgan -- which by the way is one of the classic logical fallacies: the "Appeal to Pity" or "Argumentum ad Misericordiam", which Stephen's Guide to the Logical Fallacies (link on my links page) describes thus: "the reader is persuaded to agree by sympathy".
But now we'll get some evidence mentioned -- after all, we have 30 minutes of uninterrupted radio show ahead.
Attenborough's narration mentions some of these features:
"The hypothesis claims that the features that distinguish humans from the other apes, standing upright, naked and sweaty, swimming and diving, with our very fat babies, big brain and language skills, are best explained as water adaptations."
But I found after listening that I was foolish to take Attenborough's word that we'd hear any evidence at all for most of these claims (and the claims of the first half hour) because as it turns out we only hear about those last three.
And even on those we have dubious and misleading research offered as evidence.
In fact, besides the "Appeal to Pity" logical fallacy mentioned already, this half hour is chock full of logical fallacies, so much so that it would make a good class exercise on the subject.
I'll mention some others as we go along.
First we have some hyperbole from Attenborough which, in a way, I regret having to mention.
"For forty or more years the accepted crucible of humanity was the open savanna grassland of Africa and the aquatic alternative was ridiculed. Then, really since the early 90s the consensus began to fall apart. Why? What new evidence has come to the fore in the last ten or so years to cause such a paradigm shift to drive the anthropological mainstream off the savanna and, with a certain amount of pushing and shoving, and cautious hesitation, down to the water's edge?"
First a warning: whenever you hear the words "paradigm shift" brace yourself for BS.
You won't always be hit with it -- sometimes the words really can be used and be true -- but the world of fringe science, and of pseudoscience, is where you hear it used most.
In this case, there's something more; that last half sentence unfortunately reminds me so much of the continued claims by the "intelligent design" movement that scientists are dropping evolution -- it doesn't please me to point out when AAT/H proponents talk like, or use the tactics of, the creationist and ID movements, and I wish they wouldn't do it anymore.
Until they stop doing it, though, I'll have to keep pointing it out when I see it.
And on the logical fallacy front, note that Attenborough has already used the Strawman Fallacy when he talks about the "savanna grassland" instead of mixed woodland or savanna mosaic as it's called.
Two minutes in and Dr. Michael Crawford is brought on to talk about the brain.
Crawford tells us that on the savanna "Every single species without exception lost its relative brain size as it evolved bigger."
Which isn't true but we'll get back to that.
Then Attenborough tells us that "Crawford and his team" (sometimes I wish I had a team) found that
"First that the brains of all other savanna animals had shrunk in relative size as they evolved larger bodies.
by contrast the human brain had grown 3-fold."
Which is both a strawman and also isn't true but we'll get back to that as well.
Then Crawford again: "When one compares the land-based with this universal collapse of brain size, with what goes on in the marine system I mean you've got the dolphin which is about the same body weight as a zebra; the zebra has about 360-70 g of brain in its head; the dolphin's got 1.8 kg."
This is what happens when you have people who
A) have no background in the study of evolution, and
B) don't do their homework on it before they start
C) making statements on subjects they know little or nothing about
Or, possibly, he does know what's wrong with what he's saying and is deliberately misleading others about it, which would actually be worse.
Here's the most basic problem with his statement -- he's comparing apples with oranges, or in this case, predators with herbivores, and he's picking his examples rather carefully.
One might say suspiciously carefully.
He's also ignoring the fact that all higher primates have relatively large brains, just as the various dolphin species do.
So he's essentially expressing amazement that humans are like their close relatives instead of like zebras.
I mean, really.
I've had to point out before the silliness of Morgan's amazement that we are like our relatives instead of like "the wild ass and the camel"; does it really have to pointed out yet again that it should not be considered odd that humans more closely resemble their primate relatives than they do extremely distantly related ungulates?
Brains typically do not increase in size (as measured by weight) as much as bodies do.
This is not unusual; it's something found in many aspects of scaling, such as bone diameter as one of many examples -- an animal which is twice as large typically does not have bones which are twice as large in diameter -- but these differences in scaling are broadly predictable.
The study of these scaling relationships is called "allometry" -- and brain size is one of many features studied as part of allometry.
In other words, large animals tend to have larger brains than smaller animals, so how do you know whether the larger brain is actually any bigger than you would expect it to be if it were merely due to a larger body size?
There's a way you can compare the expected brain sizes of different mammals of widely varying sizes, and see whether they are average, small-brained, or large-brained.
In dealing with increase of brain size vis a vis increase of body size there's a ratio which holds generally true across all types of mammals -- it's .7:1, (brain size to body size; sometimes said to be .67 or .68 instead of .7) and those mammals which are at exactly this ratio are said to have a brain EQ ("encephalization quotient") of 1.
This ratio actually holds true in other animals too, but you can't compare, say, reptiles to mammals with it -- reptiles with other reptiles and mammals with other mammals is fine, except for really huge mammals, like sperm whales or blue whales for instance.
And it doesn't tell you how a brain is organized or provide an exact measure of relative intelligence, although it does offer a pretty good rough guide for that.
In other words, because one animal is a 1 and another is a 1.1, that's not a huge difference and might not mean anything much, but if you have a 1 and a 3, okay, you've got something, and even smaller differences do tell us something.
You have to be careful about comparing EQs, especially when they're from different sources; differences in calculation, and of course, the
variance in a given animal's body weight can affect the EQ -- obviously if you put on 30 pounds, your EQ goes down, but you didn't actually get dumber (probably not anyway :).
But it does provide a good guide -- as good a guide as we're likely to get.
Among the things which are well-established from these studies, we know that predator species generally have higher EQs than prey species, prey species which use active predator-avoidance strategies generally have higher EQs than prey species which use passive predator-avoidance strategies, and animals which live socially, especially in relatively small groups with a lot of individual interaction, tend to have higher EQs than other species.
What you're seeing in that fact is that,
due to selection pressure during evolution, the more your species needs to think, the higher their EQ.
Larger brains are not necessarily better, because the larger the brain, the more energy it takes to develop it and feed it.
So animals seem to develop the size brain they need and that's about it.
Think of it this way.
Remember that trip you took where you had the huge suitcase and that other guy you were with had a small suitcase?
You figured you'd have everything you needed and then some and you did; the other guy had just barely what he needed and no more.
Remember how much more rested he was at the end of each day, and how much less energy it took for him to do everything?
Just how useful was that huge suitcase that had more than you needed?
Not very, right?
Same thing with brains.
Notice that when Crawford carefully picked his examples, he chose an aquatic species which fits all those higher EQ criteria and compared it to an herbivorous species which fits into pretty well all the lower EQ categories.
Then he pretends we should be surprised by the result.
Predators (which includes dolphins) typically have higher EQs than herbivores, so instead of making his apples to oranges comparison, why didn't he compare the herbivorous zebra to an aquatic herbivore, like a manatee or a dugong?
Is it because manatees and dugongs are on the lower end of the scale for mammals' EQ, doing somewhat poorer than zebras?
Or just because he's talking about diet?
If he wanted to investigate the difference in diet as the cause (which seems to be his actual aim) why didn't he pick an animals which have a diet at least somewhat like hominids, instead of a carnivore versus a grasseater?
Instead he picked the absolute highest EQ aquatic mammal (and a predator) and compared it to an herbivorous hoofed mammal, which typically have low EQs no matter where they live, and then pretended this difference was somehow odd or explainable only by an aquatic diet.
What if he had compared a seal, which after all eats a lot of fish, to a savanna baboon, which does not?
Depending on the type of seal, he'd have had either about the same EQ or slightly to much smaller EQ for the fish-eating species.
Well, that obviously wouldn't do for Crawford's thesis, so he ignores this uncomfortable fact.
This another of the logical fallacies, this one Stephen's Guide refers to as the Fallacy of Exclusion: evidence which would change the outcome of an inductive argument is excluded from consideration.
He also, of course, uses the strawman of the grasslands savanna (instead of the woodland savanna mosaic that's been used for at least a quarter century) in his zebra example.
But even when using this strawman he isn't accurate.
For instance, savanna baboons and savanna-woodland vervets have rather larger EQs than most non-ape African forest primates, which also contradicts Crawford's thesis that savannas can't support the increase of brain size.
So does he mention them? No, obviously he didn't.
In fact he ignores anything that might call his claim into question.
More "Fallacy of Exclusion".
So the end result is that Crawford is implying that this is odd and needs explanation, when actually what Crawford and his team have "discovered" is exactly what you expect.
More on EQ and what you can do, but shouldn't do, with it here.
There's the mention of Omega-3 fats and iodine as requirements for normal brain development -- that's fine.
But then there's a major non sequitur, which is yet another of the classic logical fallacies, when
Crawford says "the only way homo sapiens could end up today with 2% of his body mass as brain would be to find an
ecological resource that would provide him with the nutrients that are require for the brain to grow and
the only place you can do that is at the seashore."
It is not the only place; there are people who've calculated the amounts of energy and DHA and/or LNA fatty acids needed to develop normal brains and it's available even in savanna conditions.
He also mentions iodine and that's available too.
So here he manages to use two logical fallacies at once: the non sequitur and the Fallacy of Exclusion.
One of the odd things that pops up in the idea of the supposed need for an aquatic diet to get larger brains is the same fallacy that people use when they take megadoses of vitamins -- too little isn't good, enough is good, so lots more is better.
So instead of looking at dietary factors in terms of whether there's enough in a given environment, they look at where there's lots, and compound the error by only looking at a couple elements of a diet -- DHA, and here, iodine.
So you wind up with errors like Crawford's above and sometimes really silly statements like Attenborough's next one.
This is the statement, which may sound valid to an unschooled audience (it's supposed to) but which to someone with any knowledge of evolutionary theory (or nutrition, for that matter) should sound foolish:
"Some researchers were still skeptical.
they suggested that the brains and the bone marrow of big game on the savanna might supply the essential DHA.
But if that were the case, then surely the dominant predators, the big cats, far better equipped than a small fruit eating hominid ape to crunch through bones and skulls, would have got into the brain and marrow first, and thereby grown their own big brains.
Well, they hadn't."
Frankly, this is so uninformed it sounds like a parody of creationist thinking.
First, big cats, being predators, do have larger than average brains for their size.
Second, and more apropos, larger brains are not necessarily better, and the larger the brain, the more energy it takes to develop it and feed it.
Remember the suitcase analogy?
Another way you can see the error in this line of thinking is by asking why all creatures which eat fish don't have huge brains.
Diving ducks, sea gulls, herons, otters, seals -- why isn't Attenborough asking why they didn't outbrain us? Why aren't they at least dolphin smart? Mind you, they shouldn't necessarily be, not if you realize that large brains are not always an advantage, as all sensible evolutionary theorists do.
But if you're not sensible and imagine, as Attenborough (taking his cue from AAT/H proponents) does, that diet trumps all and therefore that big cats should be exceptionally brainy due to their diet alone, then why doesn't he wonder about all those not overly bright fish-eating species?
This dietary determinism is an offshoot of the environmental determinism seen in the AAT/H, and makes as little sense.
Crawford: "Believe you me, if you want to try and get the brain out of a buffalo skull, you're going to need a hacksaw to do it.
It's no joke.
And it would certainly would not gone round a tribe for argument's sake.
And by the time you got it home to your, where the women were, it would probably have festered and be foul."
One fairly small thing here that annoyed me; when Crawford said about obtaining and eating meat "by the time you got it home to where the women were..."
This assumes a modern human gatherer-hunter lifestyle with home bases; that kind of thinking went out at least a quarter of a century ago, although admittedly some folks still like the style.
More important here is that even if we were talking about taking back food to a home base where the women sit a'waiting, Crawford's complaint is likely wrong -- modern hunters take meat back plenty of times and plenty far; and actually one of the reasons that some researchers have suggested marrow and brains is that these bits last somewhat longer since they're essentially packaged up in containers -- especially marrow; it stays fresh enough for days.
Not as fresh as the way we'd want to eat it, mind you, but plenty safe enough for our less discriminating ancestors.
I also find it suspicious that of all the examples of braincases Crawford had at hand, he just happened to pick an animal that
A) is considered even by modern hunters to be one of the most dangerous animals in Africa
B) is therefore highly unlikely to have been hunted especially by very early hominid hunters, and
C) is partly considered so dangerous precisely because it has an unusually hard skull coupled with thick horns which make a head shot with a powerful rifle an iffy procedure.
Why not pick any of dozens, or even hundreds, of far more likely prey species? Odd that he just happened to mention that one, and only that one, out of (at least) dozens.
Then a bit later, when Stephen Cunnane compares human babies' fat to baby chimps and gorillas and found it different -- why not compare to all mammals; it's unique.
Of course comparing it to those other mammals (including aquatic mammals) wouldn't advance the AAT/H idea an iota, so the Fallacy of Exclusion is used again.
Attenborough goes on with this interestingly constructed statement: "it's predictive" because "if we switch to a new land-based diet that's poor in those nutrients brain function will suffer".
Notice the "true but false" nature of a statement like this; it's true but only when you throw in the phrase "that's poor in those nutrients".
You can say "if we switch to a new ____-based diet that's poor in those nutrients brain function will suffer" and put any environment, including "aquatic" or "shore-based", into the blank space and it will be equally true.
The statement is designed, whether deliberately or through not thinking it through, to mislead the audience into thinking that a "land-based diet" will necessarily be "poor in those nutrients".
But we know this is not true.
First, we know that peoples who don't eat seafood can and do develop normal brains and brain function, so we know that fish is not a requirement for enough of the necessary fatty acids.
We also have people who've calculated the amounts of energy and DHA and/or LNA fatty acids needed to develop normal brains and it's available even in savanna conditions.
Mentions the 2004 WHO report in regard to iodine deficiency.
Small amounts of iodine are necessary for normal brain growth and function, and iodine deficiencies do exist in some modern diets.
Fish are a good source of iodine... as are plants grown in soil with enough iodine.
Again, we know that peoples who don't eat seafood can and do develop normal brains and brain function, so we know that fish is not a requirement for enough iodine.
Attenborough mentions, for no particular reason really, the small hominid found on Flores last year, the one the researchers referred to as "hobbits".
(I say "small hominid" because from what I understand at present there's only skull and a bunch of fragmentary bones and the situation doesn't seem to be as clear as it should be to declare that a bunch of small hominids were living there; that hopefully will be clearer up later this year (2005).)
Apparently the "hobbit" reference was simply to introduce Peter Brown mentioning that there are remains of Homo (non-"hobbit") from about 845,000 years ago on the same island of Flores.
The general idea of how they got there, crossing a bit over 20 miles of water, was to drift on masses of vegetation or logs or possibly, but not as likely, lash something together as a crude raft.
Elaine Morgan sees it differently, of course, saying,
"But if you're an anthropoid ape or some variation of an anthropoid ape you don't get to construct crafts unless you're very confident in the water already and quite happy with crafts. I also think that at that stage we would have been perfectly capable of swimming across."
Which might not have been a complete non-sequitur had the creatures in question actually been anthropoid apes.
They were not "anthropoid apes"; they were Homo erectus, fairly skilled tool users for over a half million years.
While it's unknown whether they could float across on logs and such (as many animals have done for more further distances) it seems likely enough for a hominid like erectus.
If an iguana can do it, why should it be astounding that Homo erectus could do it?
On to the subject of holding one's breath (and, despite my desires at the halfway point in this half hour, I'll restrain myself from any puns on that at present).
Attenborough again: "in land mammals, including our primate cousins the chimps and gorillas, breathing is entirely involuntary; you can't get a chimp to hold his breath. Breathing is as unconscious as the beat of its heart."
I don't know if the ape part of that claim that is really true or definitely false -- Attenborough offers no evidence for the claim, but it might be true.
However, we do know that some land mammals at least, dogs for instance, can hold their breath, and that untrained dogs can hold their breath somewhat longer than untrained humans.
So the statement overall is simply untrue.
The amount of fine control we have over our breathing is very unusual and is apparently a side benefit of habitual human-style bipedal locomotion.
Not using the muscles of the thorax in locomotion frees them from that relatively involuntary chore, allowing them to be used in better breathing control, which helps a lot in advanced forms of speech.
Attenborough ignores these fact so he can advance the AAT/H view; he outlines it like this:
fully committed aquatic mammals such as dolphins -- conscious breathing
"fully aquatic, exclusively conscious; fully land-based, exclusively unconscious"
Humans, half and half.
Dogs he doesn't mention; one of those ugly fact things, I guess.
Hoover the seal is brought in as evidence that conscious breathing necessary for speech:
"It's said he was the only non-human mammal ever to make the sounds of human speech."
It may be "said", but the TV show America's Funniest Videos would disagree; they regularly have dogs and cats which make the sounds of human speech.
However, Hoover was an unusual case -- he apparently did actually mimic a few phrases learned from his former owners -- common in some birds but something never before seen in any mammal, including any aquatic mammal.
However, W. Tecumseh Fitch (you see him mentioned on my page re the larynx) is getting some people working on this, since it's an interesting possibility.
However, it doesn't really mean that swimming and diving are prerequisites for speech, as Attenborough would obviously like to imply.
Now it's on to the "swimming babies" business.
"Diving response and natural swimming abilities are displayed extremely early in the growth of the human infant. Indeed they are strongest at birth."
If you haven't already, read my page on "Swimming Babies" for more info on this.
What he's describing is not unique to humans or to non-terrestrial mammalian infants; it's a universal mammalian response, possibly a holdover from pre-mammalian ancestors.
This is why I have that Darwin quote on my opening page; these "false facts" just never go away.
Attenborough then has Susan Burvill, consultant midwife at Addenbrooke's Hospital at Cambridge, mention the diving reflex, this time in a way that suggests it's something odd or in need of explanation in human infants: "when they're born they still have intact the diving reflex, or we call it the duck reflex, what that means if there's water on the face, there's receptors on the face, that will close the throat off so actually the baby not inhale water."
Rather than being something odd about humans or human infants, it's actually found in all mammals (and birds and reptiles as well), whether terrestrial or aquatic.
Like the infant swimming response, AAT/H proponents here look at a feature that humans share with all mammals and are surprised that it should be so.
Various things about water birth, which Attenborough suggests "seems extraordinary" -- but why wouldn't a baby which has spent 9 months floating in the watery environment of the womb do fine going from there to a pool of water for a very brief period?
Why would anyone find that "extraordinary"?
Like the business of being surprised that we resemble our primate relatives instead of various distantly related ungulates, like being surprised at humans having features which are present in all mammals -- why are these people continually baffled by the expected?
Now we get into something interesting, and something I haven't researched thoroughly.
It's the vernix caseosa, which is a white substance composed of sebum (the excretions of sebaceous glands) and sloughed off skin cells in babies which are either preterm or at term (it's gone in postterm babies).
It apparently has antibacterial properties, and it was supposedly found only in humans.
Attenborough's research crew apparently found a researcher in Nova Scotia, Don Bowen (the way they put it makes it sound like Bowen found them), who says he's found something which he assumes is similar in newborn harbor seals, and to a much lesser extent in grey seals, but although "we always assumed that it was analogous to the vernix that humans are born with; we never pursued it systematically."
Attenborough grabs this thread and spins a thick warm jumper out of it, but it would be nice to have enough threads to make at least a bit of yarn before you start spinning yarns.
Actually, this is one of the basic problems in AAT/H techniques, now I think about it; not the worst one, certainly, but a problem nevertheless.
Before spinning a story about it, wouldn't it be apropos to ask some interesting questions?
And there are some fascinating questions that immediately come to mind:
A) is this feature in seals actually essentially the same as in humans -- sebum plus dead skin cells? (knowing what I do about seals' skin and glands, I think it likely is, but it would be sensible to know for sure before putting it forth as evidence.)
B) if despite people knowing about the vernix in humans it wasn't known to be present in seals until now might it not also be found in other mammals if one searched hard enough?
(AAT/H proponents often seem to make the mistake of assuming we know all the comparative angles between various animals, so if we don't know if a feature exists it means we know it doesn't.
The two -- not knowing and knowing it doesn't -- are not the same thing.)
C) and might the feature not also be one of those things, like the hymen, which happen to be present in various unrelated mammals (humans, lemurs, llamas, guinea pigs, hyenas, elephants, rats, horses, some species of galago, toothed whales, seals, and sirenia) apparently by chance?
All of these are interesting, even fascinating questions, and so (naturally, it seems) Attenborough doesn't ask any of them, much less try to answer them.
(This too seems to be par for the course with AAT/H proponents, I'm sorry to have to say.)
So, some form of vernix seen in a few seals... interesting? definitely yes. Evidence for an aquatic past? like the hymen, no, not really, not unless there's a lot more to it than meets the eye so far.
But it is interesting and bears an actual thorough looksee.
Doing that, however, is not the general method I've seen in AAT/H proponents -- they tend to throw something out in the ring (either factual or "false fact"), claim it's evidence, and if it needs further looking at to see if it is evidence or not, they expect someone else to do that.
And that's what Attenborough did here with the vernix.
Update: I notice that Robert Yerkes and James Elder noted vernix caseosa being present in the chimpanzee;
I've also seen reference in academic papers about the pre-birth inhalation of vernix caseosa in baboons.
I'd like to see more info on this.
You can find many categorical statements, often by medical scholars, that the vernix caseosa is not found in any non-human primate, but then a decade or so ago you could find the same kind of emphatic statement about the descended larynx, which we know is false.
Cuba, case 12, exhibited no fear of her baby or reluctance to
handle it, but she did so awkwardly, often holding it head down.
She was observed to bite one of its feet as if testing its edibility, and
she scraped the lower back with teeth and lips so hard that it looked
as if she were removing the skin. Actually she took off only a
coating of vernix caseosa which overlay the hair.
Attenborough closes with the claim that
"the evidence, bit by bit, and year by year, really does seem to be accumulating in its favor. Perhaps, like Wegener and his continental drift, the tide really is turning towards Alister Hardy and Elaine Morgan and their proposal that our earliest human ancestors were born, not on the grasslands or the forest but in the shallows and the dunes on the margins between sea and land."
Ahh, Wegener again; when he was alive the guy went around the world in the pursuit of his studies but I swear he gets out more now.
Everyone wants to be Wegener, or at least the false story of Wegener they use.
Well, it would've been nice if Attenborough had presented that "accumulating" evidence -- what about the many features he mentioned, the "standing upright, naked and sweaty, swimming and diving", the "strange hairlessness", the "layer of fat just beneath the skin", the "curious paradox that noses are very large but our sense of smell is comparatively poor", and of course "our bipedal locomotion on two legs" (not just bipedal but bipedal on two legs)?
Well, maybe he's planning a sequel.
Robert Yerkes and James Elder, pp. 46-47, "Concerning reproduction in the chimpanzee", Yale J Biol Med. 1937 October; 10(1): 41–48
Just before winding up he quotes anthropologists Cameron and Groves saying
"Morgan's latest arguments have reached a sophistication that simply demands to be taken seriously."
Read my site -- that's why I did it.