I wrote:
>>But how would you want to increase the brain size of a given
>>individual?
>>Brain size is limited by the size of the skull.
>>And more important: the count of the neurons is growing only in the
>>first 3 months after birth - after that neurons are decreasing....
>>So nutrition could only influence effective brain growth up to the
>>age of 3 months.

Wade H. Reeser wrote:
>Come on Amadeus!  I'm sure even you can see that the brain
>of an adult
>is MUCH larger than that of a 3 month old regardless of
>it having the
>full complement of neurons.  Perhaps its all water weight...  In any
>event, nutrition is found to play a critical role
>in brain development
>and intelligence for the growing child.
>  Wade Reeser

Sure Wade, the brain of the adult is bigger, but the count of
neurons only decreases.
And the brain growth in size *is* influenced
by nutrition after 3 months.
The connection between the neurons, establishing in the following
years, determines the brain capacities of equal neuron count.
But why is the brain bigger then?
More synapses, more nerves, more water? Bigger neurons with bigger
energy stocks? Bigger glia-cells isolating between them?
I guess it's a combination of them, or more factors.
Nutrition will influence the structural quality inside the brain,
as Ben and I seem to agree.
(I tried to list a few promoting nutrition factors).

The question was if it was possible to infer from nutrition to brain
size as a evolutionary developement.
I can see some influences (i listed some) which will enhance
the brain functions later on.
But brain developement as an evolutionary step IMO can't be seen
as mere size. Or we could see a decrease from Neanderthal to Cro

Magnon.
But Neanderthals had a limited intellectual performance, e.g.
the slow developement of tools and absence of art
(These observations taken from Jared Diamond "The third Chimpanzee")

Cro Magnons made the big leaps forward with a fast developement of
tools and developement of art (cave art, fishhooks, nets
advanced clothing and stone tools, to list some).
All known hunter/gatherer populations of today are Cro Magnons,
Australian Aboriginals, Inuit and !Kung.

The biggest intelectual achievements (housing, language, writing.
science,... up to computers)
were made in neolithic times, as one could argue.

IMO the obvious decrease of skull capacity from neanderthals
to roman empire simultaneously resulted in a big enhancement
of brains *capability*. As far as nutrition is concerned in this
developement, the roman empire nutrition may have provided
better conditions as the neanderthals'.
May have.

regards
Amadeus

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