On Sat, 21 Aug 1999 Don and Rachel Matesz wrote:
>To all who responded to and "criticised" my post on nutrition and
evolution
>of the brain and nervous system:
>
>There are too many to respond to directly; I don't have the time to
do so
>and my response would take up too many pages for thise venue. My
suggestion
>is that you read NUTRITION AND EVOLUTION (Keats 1995) by Crawford
and Marsh,
>which should answer all of your questions...
I'm sorry that you choose to direct us to a book instead of
responding directly to a given argument.
In a book the author can follow his own
trace of ideas without the need to reflect or go into detail on any
dialogue. This is a chance we have missed in this case,
and you for the book you seem to plan too.
>...and also provides a very convincing
>argument and evidence that mankind did not evolve on the savanna,
>but in coastal ecosystems.
I have heared in the past of some kind of "aquatic" theories, in
which humans evolved near the sea - but not evidence of course.
This would lead to mollusks (clams oysters...) as a source of higher
fats (as DHA or EPA).
These are obtainable without fishhooks and nets,
and these tools werent available until recently
(maybe 50k years - at least only
with Cro Magnons - not older than 100k years).
This makes only a small part of the claimed 2 million years in the
african savanne.
Other Sea fish like salmon, which change to sweet waters
in a season of the year may be huntable like the bears do, but
contribute only a smaller part.
Ok, mollusks, why not.
In my vacancy in the Bretagne seaside (part of France)
i saw a real long coastline with mollusks,
accessible 2 times a day (low tide :-) ).
More sympathic as eating brains?
Even for ethical vegetarians,
oysters seem to be one of the most primitive
kind of animal to think of. Perhaps easier to kill than a rabbit.
There was a culture in the area of Denmark called something like
"koekenmoedinger" - they left gigantic piles of mollusc shells
(but neolithic, i think).
Where are the african shell piles? Of 2 million years?
>BTW, it is not true that the only sources of DHA are brains
>and marrow.
>This fat is found in abundance in ocean fish and fat of sea
>mammals; eye balls; egg yolks (especially of water birds);
>and even some in 'regular'
>animal fats (especially from grass fed animals).
>Marine animals are the
>best sources.
A good w-3 fat source listing is at the Omega plan website:
http://www.teleport.com/~jor/#tff
No doubt that clams or fish are a valuable source of many
essential food resources. Especially for cultures, where some items
are really low in supply - like for inuit, coastal regions or w-3
fats in the western diet.
But if other primates' brains grow in the same speed as ours,
ours just growing for a longer time, then a DHA sysnthetisation rate
or supply similar to gorilla should be enough, isn't it?
A small pump, pumping a longer time can pump the same amount
as a very big pump in a shorter time.
If the brains of farmers children of, let say Maine, USA who seldom
ever eat or ate brain or fish or eyeballs are equal size than
in rest of the world -
then there must be a different sufficient kind of supply.
About the time table of decreasing brain size:
Brain drastically increased from 2mio years to 1mio years back.
Brain was at peak in neanderthals
- no art - few technology developement.
Brain size decreased when Cro Magnons came.
Cave art. Quick developping technology (nets, fishhooks, needles,
stone tools).
Mere size of the brain doesn't seem to account for its
proper function. The best brain achievements are
in the neolithical era, no doubt. Doubt?
I just begun reading "The Third Chimpanzee" by Jared Diamond
mentioned by Todd Moody. Thanks Todd, I'm enjoying.
Interesting stuff about neanderthals, hunting and so on.
regards
Amadeus
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