Lots to reply to. Luckily I've already researched much of this stuff in the past and saved some of what I found. I shortened it some by not quoting Tyler much, though this risks some confusion.
Evidence for Increased Malocclusion from Modern Diets over Traditional Diets vs. No Counter-evidence Yet OfferredTyler, first you claimed that Price only focused on caries, now you admit he examined occlusion but dismiss his evidence on that. Given that I don't think raw dairy is healthful, I am also suspicious about some of Price's conclusions, but your dismissals without evidence are not of much value to me. To disprove Price, it should be a fairly simple matter of finding rates of malocclusion among hunter-gatherers and other traditional populations equal to those in modern populations. Has anyone done this?
As I pointed out, the WAPF also provides evidence of dramatic single-generation improvements in occlusion through change to more traditional diets (such as a comparison photo of mother and child). I can't find that evidence at present, so I hope you'll take my word for it at present that they presented it. I'm no fan of theirs, so I have no motivation to mislead about this. If you assume that evidence was also selectively chosen it should once again be a fairly simple matter for WAPF critics to show examples of children who were fed much more traditional diets yet fared no better with malocclusion, caries, etc. than their parents. Has anyone done this?
The WAPF also provides this:
Some pesticides can also react with thyroid hormones and vitamin A receptors.[Rolland, RR. A review of chemically-induced alterations in thyroid and vitamin A status from field studies of wildlife and fish. Journal of Wildlife Diseases 2000, 36(4):15-35.] The disruption of fat-soluble activators and mineral metabolism would explain the bone deformities and malocclusions showing up in the wildlife in the Bitterroot Valley. http://westonaprice.org/envtoxins/clouds.html
And this at
http://westonaprice.org/envtoxins/clouds_pictures.html: a photo of a filly foal, with "a 7 mm underbite at 2 days old when this photo was taken. The foal was given Calc. Phos. 6X and Bioplasma 2 times per day, morning and night, from birth" followed by a photo of the "Same filly foal at 13 days old, with perfect bite."
Do you have counter-evidence to this? As I've said before, unsupported claims made with certainty, based solely on one's say-so, raise my suspicion-meter more than anything. Even if we grant that Weston Price was a "total fraud" based solely on your say-so, then what about the similar findings of Jared Diamond, Tanchou, Stefansson, Washburn, Eaton, Cordain, Lindeberg, etc. re: the superior health and morphology of people eating more traditional/ancestral diets, including Cordain on malocclusion based on observational evidence and bones and fossils? Do you have evdince to show that all of it worthless?
Here are a couple of examples:
Sherwood Washburn in 1951 highlighted the importance of evolutionary processes and contexts rather than simply the results of these processes. Washburn discussed evolutionary changes in the lower jaw and suggested that understanding how the facial region has evolved in the human lineage and how it develops in the individual will “open the way to...interpretation of abnormalities abnormalities and malocclusion, and may lead to advances in genetics, anatomy, and medicine” (Washburn 1951, p. 304).
Source: Evolutionary Medicine, Wenda R. Trevathan, http://www.appalachianbioanth.org/trevathan.pdf
From The Paleo Diet, by Loren Cordain, pp. 42-43 (emphasis mine):
Hello Grains, Hello Health Problems
The archaeological record clearly shows that whenever and wherever ancient humans sowed [cereal grain] seeds (and replaced the old animal-dominated diets), part of the harvest included health problems. One physical ramification of the new diet was immediately obvious: Early farmers were markedly shorter than their ancestors. In Turkey and Greece, for example, preagricultural men stood 5 feet 9 inches tall [on average] and women 5 feet 5 inches. By 3000 B.C., the average man had shrunk to 5 feet 3 inches and the average woman to 5 feet. But getting shorter--not in itself a health problem--was the least of the changes in these early farmers. Studies of their bones and teeth have revealed that these people were basically a mess: They had more infectious diseases than their ancestors, more childhood mortality, and shorter life spans in general. They also had more osteoporosis, rickets, and other bone mineral disorders, thanks to the cereal-based diets. For the first time, humans were plagued with vitamin- and mineral-deficiency diseases--scurvy, beriberi, pellagra, vitamin A and zinc deficiencies, and iron-deficiency anemia. Instead of the well-formed, strong teeth their ancestors had, there were now cavities. Their jaws, which were formerly square and roomy, were suddenly too small for their teeth, which overlapped each other.
I already agreed with you that cooking is a factor in malocclusion. Based on the accumulating evidence, the types of foods eaten appear to be an even more important factor in malocclusion. Sorry, but I find your dismissals of such unconvincing.
Lack of Evidence for Neoteny Contributing to Increased Brain Size & IntelligenceYour suggestion that smaller dogs are less intelligent than larger dogs would appear to also argue against increases in brain size and intelligence from selected neoteny, as "toy" dogs like chihuahuas are reportedly the most severely neotenized of all breeds. As Budiansky reportedly argued: "Toy dogs often display an extreme level of neoteny, resembling not just infant, but fetal wolves."
http://en.wikipedia.org/wiki/Neoteny, sourcing Budiansky, Stephen, 1999, The Covenant of the Wild: Why animals chose domestication. Yale University Press. ISBN 0300079931), whereas the Alaskan breeds and large shepherd dogs are considered to be some of the least changed breeds from wild ancestors:
"The Canadian Eskimo Dog is an Arctic breed of dog (Canis lupus familiaris), which is often considered to be North America’s oldest and rarest remaining purebred indigenous domestic canine." (
http://en.wikipedia.org/wiki/Canadian_Eskimo_Dog)
Note here how early domesticated dogs, the ancestors of the big dogs that you claim are more intelligent, ate big game that may have provided generous sources of marrow, suet and back fat to their human owners and possibly also to the dogs:
"In shape, the Paleolithic dogs most resemble the Siberian husky, but in size, however, they were somewhat larger, probably comparable to large shepherd dogs," added Germonpré, a paleontologist at the Royal Belgian Institute of Natural Sciences. .... Isotopic analysis of the animals' bones found that the earliest dogs consumed horse, musk ox and reindeer, but not fish or seafood. Since the Aurignacians are believed to have hunted big game and fished at different times of the year, the researchers think the dogs might have enjoyed meaty handouts during certain seasons." ("World's first dog lived 31,700 years ago, ate big: Discovery could push back the date for the earliest dog by 17,700 years, By Jennifer Viegas, Discovery Channel, updated 2:17 p.m. ET, Fri., Oct . 17, 2008,
http://www.msnbc.msn.com/id/27240370)
Technology and NeotenyI agree that technology such as hunting weapons likely also contributed to neoteny and the evidence suggests that the causes of brain growth were multifactorial, of which dietary change in types of foods eaten was an important one. I find your dismissals of dietary contributions unconvincing. I find evidence more convincing than opinions.
I don't see increases in the periods of frail childhood dependency on adults as a "good sign" of physical health. It seems more a sign of increasing physical degeneration compensated for by increasingly complex social structures and other adaptations (such as technology). Arguing that the necessity of extended childhood is a "good sign" is like arguing that myopia is a good sign because it inspired ingenuity in the development of vision correction technologies.
Brain/Body RatioAll the evidence I found said that human brain/body ratio has been pretty steady for the last 10,000 or more years. You will find me relatively open-minded on all topics. So if you have evidence to the contrary, I'd be interested in it. As for difficult births (dystocia), they are rare among hunter gatherers, particularly the more carnivorous ones, indicating once again the critical importance of the types of foods eaten:
A Darwinian View of Obstructed Labor
Robert P. Roy, MD, FRCSC
Obstetrics & Gynecology 2003;101:397-401
The American College of Obstetricians and Gynecologists
http://www.greenjournal.org/cgi/content/abstract/101/2/397
"This essay discusses the evolutionary biology of dystocia. From a Darwinian standpoint, the high frequency of dystocia observed today seems evolutionarily untenable. Hunter-gatherers, most notably the Inuit, appear not to suffer from dystocia. ...."
So a more carnivorous diet appears to have not only contributed to the development of larger brains and bodies in humans, but also better enabled the birthing of these larger-brained children than modern diets.
Is Brain Sulsification an Advantage of Neolithic Diets?If you have evidence of increased sulsification deriving from a Neolithic diet across all ecological environments and geographic regions, please provide it. Are you implying from your remarks on sulsification that the Neolithic diet is superior to the Paleolithic diet with regards to effects on the brain? I've noticed that the vast majority of your posts are positive about the raw aspect of RPD, but rarely the Paleo aspect. Do you believe in the healthiness of Paleo, or just of raw nondairy, nongrain, nonlegume? In other words, do you think that the Paleo diet was overall superior to the Neolithic diet, including Paleo's higher levels of meats and animal fats and lower-glycemic wild plants, or just certain aspects of Paleo (such as no dairy, grain, legumes or additives)?
Brain size and IntelligenceTyler wrote: "...so that brain-size isn't necessarily the only factor - if it were the sole factor, presumably, the Inuit would be beating everyone else re Nobel Prizes/Mensa or whatever."
Of course brain size isn't the only factor in intelligence, when evolutionary biologists speak of the increasing intelligence of hominids as brain size increased, that does not mean they are attributing intelligence solely to brain size. As regards the Inuit and other HGs, Jared Diamond actually has argued that HGs like those of Papua New Guinea are probably more intelligent ON AVERAGE than moderners. Whether Diamond is right or wrong about that, moderners will always win any intelligence competition because there are 6+ billion of them vs. 300,000 HGs by the last estimate I saw--so the odds of moderners producing exceptional geniuses are far greater on the basis of sheer volume. The fact that HGs who are still eating their traditional diet don't tend to participate in activities that lead to Nobel Prizes and Mensa memberships is of course another factor revealing the Nobel/Mensa argument to be a nonsensical canard.
More research is needed in this area, but wild animals provide some interesting clues:
"Domestication of the wolf over time has produced a number of physical changes typical of all domesticated mammals. These include: a reduction in overall size; changes in coat colouration and markings; a shorter jaw initially with crowding of the teeth and, later, with the shrinking in size of the teeth; a reduction in brain size and intelligence and thus in cranial capacity (particularly those areas relating to alertness and sensory processing, necessary in the wild); and the development of a pronounced "stop", or vertical drop in front of the forehead (brachycephaly)." (en.wikipedia.org/wiki/Origin_of_the_domestic_dog)
Are you arguing that brain size started declining precipitously exactly 35k years ago, whereas plant foods were not a significant part of human diets until at least 30k years ago, therefore making a connection impossible? What change do you posit suddenly occurred 35k years ago that accounts for decreasing brain size since that time and what reason for the critical certainty regarding that precise millenium?
Starting Points of Increased Plant Food Consumption vs. Brain Size Decline in the Upper PaleolithicTyler wrote: "First of all, it's pretty clear that Barry Groves just arbitrarily picked that 30,000 figure [for the start of increased plant foods in the diet] out of thin air."
I'm not inclined to believe that accusation based solely on your say-so. It's quite a coincidence that Clive Gamble picked the same figure for the approximate end of the Middle Paleolithic and Carnivore Guild. Apparently I'm expected to believe that he too picked it "out of thin air"? Isn't it more likely that Groves read about it somewhere, as I did, and was just repeating what he read?
Tyler wrote: "So far, there is no reason to assume that plant-eating suddenly expanded around that time, given the available evidence. ... There are plenty of other explanations. One could be that humans were no longer subject to natural selection by that stage, thus not being selected by nature for higher IQ. Another explanation I gave earlier is that some areas(eg:- frontal lobe) may have expanded while other areas contracted much more, being less "essential". Also, the very minor -3% figure is substantially less than the -8% figure so it is much more likely to be due to non-dietary factors than the larger -8% figure."
These speculations are interesting, but I'm not assuming anything is correct without evidence. So which do you propose to be the main factors in brain decline that started at your chosen 35k ya figure, or any other figure you may choose (75k ya was another figure cited in a source I found today), and what evidence do you have to support it?
Do you not find it an interesting coincidence that human brain size reached its peak during the Carnivore Guild and declined most dramatically during the Neolithic? At the very least, it would seem that meat eating does not guarantee brain shrinkage and plant eating does not guarantee avoiding it.
Tyler wrote: "...the main transition to plant-foods only started c.20,000 years ago when the Mesolithic era started in the Middle-East. Granted, it took even longer for plant-foods to be introduced into other regions. But the point is that 30,000(or 40,000 or further) years for plant-foods is way too much, given the scientific data."
Thanks for those specifics, do you have any data to support this? Your more recent figure for transition to more plant foods in the diet would seem to suggest that we may be even less adapted to plants than the 30,000-40,000 figures would suggest, yes?
Here is some more evidence I found that uses your 35,000 ybp figure for brain-size decline and correlates it with decreased animal foods:
Paleolithic Diet vs. Vegetarianism: What was humanity's original, natural diet? A 3-Part Visit with Ward Nicholson
Part 1: Setting the Scientific Record Straight on Humanity's Evolutionary Prehistoric Diet and Ape Diets
(LAST UPDATED 3/24/2000)
http://www.beyondveg.com/nicholson-w/hb/hb-interview1f.shtml
Human brain size since the late Paleolithic has decreased in tandem with decreasing contribution of animal food to diet. In addition, a recent analysis updating the picture of encephalization (relative brain size) changes in humans during our evolutionary history has revealed that human cranial capacity has decreased by 11% in the last 35,000 years, the bulk of it (8%) in the last 10,000 [Ruff, Trinkaus, and Holliday 1997]. Eaton [1998] notes that this correlates well with decreasing amounts of animal food in the human diet during this timeframe. (Of particular relevance here is that most of this decrease in animal foods correlates with the dawn of agriculture 10,000 years ago.)
However, here is another source that muddies the waters for both of us, citing peak brain size at 75k ybp and pointing to social changes as well as increased foraging (in other words, increased plant and small-animal foods) to explain it.
Rambling Road to Humanity: Anthropologists debunk another myth of evolutionary progress
Scientific American
Corey S. Powell and W. Wayt Gibbs, staff writers
http://forum.lowcarber.org/showthread.php?t=50889
Hominid brains appear to have remained fairly constant in size for a very long stretch from 1.8 million years ago until about 600,000 years ago--a "period of stasis" whose reality has long been debated by scientists. An abrupt break occurred during the Middle Pleistocene epoch (from 600,000 to 150,000 years before the present), when fossils show that the cranial capacity of our ancestors skyrocketed. This trend peaked roughly 75,000 years ago, when archaic Homo sapiens fossils (a category that includes the well-known Neanderthals) indicate a brain mass of about 1,440 grams. Since then, brain mass has actually drifted downward to the 1,300 grams that is typical today.
Brain size alone does not tell the whole story, of course. Intelligence seems to have less to do with brain size per se than with the brain's proportion to the body it must care for and control (and even that link is rather tenuous). Here, too, the results of the Nature paper are telling. Over the nearly two-million-year span that Ruff and his co-authors examined, ancient hominids were on average about 10 percent more massive than modern humans. Body size peaked about 50,000 years ago: Neanderthals were muscular brutes who weighed upwards of a quarter more than modern humans. Since that time, humans have been marching steadily downhill in both stature and cranial capacity (with the exception of some recent gains due to improved nutrition and reduced disease). The good news is that the steeper decline in body mass over the past 50,000 years has raised our ratio of brain to body above Neanderthal levels, even though total brain mass has dipped.
...
In considering the new reconstructions of Homo over the past 90,000 years, Kappelman is struck less by the roughly constant brain size than by the rapid decrease in body size, which runs quite counter to the earlier steady or upward trends. He suggests that this decrease in overall bulk was favored "by a social structure that relied on more cooperative foraging and better communication skills." At the same time, a better and more reliable food supply could support the metabolic demands of a large brain. "The increase in relative brain size of modern humans may then be, in part, an effect of selection for smaller body mass," Kappelman rather ignominiously concludes.
So this is what it has come to. The favored son of the Garden of Eden has been demoted to the incredible shrinking human.
The following evidence of the deleterious effects of plant foods shows that where Weston Price erred was in underestimating the importance of animal meats/fats and the damage that even somewhat older Neolithic plant foods (and I would add raw dairy) do:
"The following 2 websites go on about the gradual decrease in height of (pre-1769)Maori skeletons, over the centuries, as they turned to eating grains, including a few mentions of frequent stomach-tumours in the Maori population, and the excessive wearing of teeth, especially molars, due to consumption of plant foods. They do have one or two nice things to say about Maori health, but mostly they mention the low rate of life-expectancy(25-30 years), the low fertility, the high susceptibility to disease etc in pre-colonial times:-
http://tinyurl.com/gs5oyhttp://tinyurl.com/kk5vu"
--Geoff Purcell
http://health.groups.yahoo.com/group/rawpaleodiet/message/1107
