in refutation to the  argument about brain building requirements for humans
presented by Don, this argument have been presented:

<we actually develop bigger brains by growing them for longer (not faster),
<and most or all of the growth is completed during lactation

<for a fuller rebuttal of the paleodiet sci-fi, see my encephalisation page

<www.nildram.co.uk/veganmc/encephal.htm

<(this has some real graphs and numbers in it)>

what do you think of this argument?
jean-claude

DOn article was:
>Wrt the article on cooked vegetables "Early humans got smart by cooking
>veggies, study says":  This idea that we got smart by cooking vegetables,
>not by hunting and meat eating, may be politically correct, but it is
>illogical and biochemically incredible.  Here are my reasons:
>
>1)   Cooking is a highly sophisticated behavior that requires intelligence
>not had by any other primate.   No non-human primate cooks.  Our closest
>primate relatives, the chimps, do hunt.  Therefore, hunting definitely
>preceded cooking.  The "advance" from eating everything raw to using fire
>for cooking had to wait for improvements in brain capacity, hand eye
>coordination, manual dexterity, etc.  In other words, cooking could not
have
>become common activity for man until after his nervous system had developed
>beyond that of the chimps.   Hence, cooking must have come after man became
>"smart"--in other words, man did not become "smart" by cooking, he started
>cooking after becoming "smart".
>
>2)  Further, there is nothing in cooked vegetables that would support
>development of a more sophisticated nervous system or brain.  The primary
>structural material of the brain is the omega-3 EFA known as DHA
>(Docosahexaenoic acid).  There are no vegetables that provide DHA.  Greens
>provide alpha-linolenic acid, which some animals can convert to DHA, but
>modern humans have little or no ability to achieve this conversion.
Chimps
>also obviously have no marked ability to achieve this conversion--if they
>did, they'd probably have bigger brains.  In fact, there is no mammal that
>is capable of making enough DHA from scratch to produce a large brain.  So
>there is no reason to believe that early man had any ability to make large
>amounts of DHA out of the alpha-linolenic acid (ALA) found in green leaves.
>Furthermore, it has been estimated that even in the best of ALA converters,
>it takes 10 grams of ALA to produce just one gram of DHA.   The absolute
>amount of ALA in green leaves is very small, on average less than one half
>gram per 100 gram portion, so literally enormous amounts of green leaves
>would have to be eaten to get significant amounts of DHA.  Mankind simply
>does not have the kind of gut needed to process that amount of greens.
>Finally, ALA is heat-labile, so cooking greens would have destroyed much of
>the value of ALA.
>
>3)  The authors of this "research" say "We don't see meat as a high energy
>food source.  It has to be (a) high energy food source to explain this
>doubling of body size."  If they don't see meat as a high-energy food
source
>and think that cooked vegetables are high-energy foods, I suggest that they
>try living on nothing but cooked vegetables for a few weeks.  Here are some
>facts:
>
>Energy value for one cup portions (one cup of raw meat is approximately 8 -
>9 ounces):
>
>Food                                            Calories
>
>Cabbage, cooked                                32
>Kale, cooked                                     40
>Broccoli, cooked                               50
>Pumpkin, cooked                                50
>Onions, cooked                                 60
>Carrots, cooked                                70
>Winter squash, cooked                      110
>Sweet potato, boiled and mashed        364
>
>Nuts, raw                                       933
>
>Eggs, eight medium raw                     640
>
>Wild game, raw, lean only                  232    (Average, taken from
>Eaton, et al Paleolithic Prescription)
>
>Beef brains, raw                              392
>
>Animal fat, raw                               1840    (This would represent
>marrow,  storage fat, etc.)
>
>From these figures it is hard to understand how the authors of the "study"
>in question could conclude that cooking vegetables gave early man access to
>"high energy" foods.  My guess is that the authors have not looked at
energy
>density in terms of volume, i.e. calories per cup, but have been misled by
>looking only at calories per gram.   If you look at calories per cup, the
>only vegetable that on a cup for cup basis comes near to the energy value
of
>wild game lean meat is the tuber sweet potato.  A hunter gatherer would
have
>to eat two cups of cooked winter squash, over three cups of cooked carrots,
>nearly four cups of cooked onions, or nearly six cups of cooked green leafy
>vegetables to equal just one cup of raw lean meat.   Brains are higher in
>fat, so they are almost twice as energy dense as lean meat; the fat content
>of brains is not affected by feeding practices--the brains of wild game are
>just as rich in fat as are the brains of domesticated cattle.  Eggs also
are
>much more energy dense than vegetables.  Further, it is known that not only
>aboriginal people but also chimpanzees eat raw brains and eggs when they
can
>get them.   So we don't have to guess that maybe early man ate those
>things--it would be odd if he didn't.
>
>Now take a look at nuts--which are mostly fat-- and animal fat--THERE IS
THE
>ENERGY DENSITY REQUIRED!  Again, it is known that both chimps and
aboriginal
>people eat marrow and kidney fat.  But "primitive" people eat more meat and
>more fat than chimps.
>
>The idea that cooking vegetables was the key to a high energy density diet
>is absurd.  The easiest way for a primate to get a high energy density diet
>is to EAT BRAINS AND MARROW FAT.  This is also the best way to increase
>intake of linoleic acid, EPA, DHA, and other fats needed for development
and
>maintenance of sophisticated eyes, brain, nervous and vascular systems.
>
>But eating brains and marrow fat is politically incorrect these days.  With
>all the popular hysteria about the dangers of eating organ meats and fat,
>who is going to publish a head-line stating that "EARLY MAN DEVELOPED A BIG
>BRAIN BY EATING BRAINS AND FAT, STUDY SAYS"?
>
>This is one of the worst examples of junk reporting and junk science we've
>seen in a while.  By presenting this half-baked politically correct
>supposition to the public before the scientific community has an
opportunity
>to comment upon it, the authors of this supposed research will be patted on
>the back, and their "conclusions" will be by many laymen accepted as
>"fact"--after all, it is very unlikely that Reuters will in a few days
>publish with bold headlines all of the logical and biochemical objections I
>or any one else will have to their mistake.
>
>Don Matesz
>
>Sorry, it's so long..... Rachel Matesz ;-/