On Wed, 28 Aug 2002 08:13:26 -0500, Herb Finkelstein <[log in to unmask]>
wrote:

>Recall, however, that in the last 35000 years human brain size has in fact
>decreased by 11%. Most of that decrease (8% of the 11%) has come in just
>the last 10000 years.

Do you have some other reference on this as the one in "beyondveg"?
I'm thinking in particular of neanderthals.
Neanderthals had the biggest brain (well, skull volume) ever, a peak.

But only the near east neanderthals (today's Israel) were the big ones.
Taller than 1.80m . European neanderthals were only 1.55m tall.

Did the comparison compare neanderthals and cro magnons (apples and pears)?

>.. there is obviously
>still a large quota of intelligence in the human brain even given that it
>is 11% smaller now.

I'd say there is obviously a much *bigger* intelligence in the modern human
brain than in the 11% bigger brain of the biggest neanderthal.
Their "technology" (stone splits and bone needles, clothing weapons)
remained constant for 100,000 years.

>What is noteworthy about the brain size decrease over the last 35000 years
>is that not only has it come during a time period when DHA consumption has
>decreased considerably,

20k years ago was the peak of ice age.
Agriculture in europe didn't develope earlier than 4,600 bc.
Before that, at least before 10,000 *all* people were paleolithic
huntergatherers, in northern areas probably only hunters.
There is no hint that the DHA intake has decreased between 35,000 and
10,000. To the opposite, the hunting skills after 40,000bc reached a peak.

What was the reason then, for the brain (volume) decrease?

From mere brain volume you can't infer to intellectual abilities.
Or have women less average IQ, with their (100g) smaller brain?

Or are elephants 4 times as intelligent as humans?
They have a  4 times as big brain.

There are such parameters like the count of neurons and the count of
connections between them.
We don't know if the neanderthal brain needed to have been so big because it
had much more of the insulating glia-cells between neurons.
They could still have had much less neurons.

It could be they needed more volume to cope with more concussions to be
expected from their brute-force hunting style (no bows/arrows...).

Maybe smaller brains with more cells and shorter connections between them
work even better. Like Einstein's.

Some of this topics are discussed at:
http://serendip.brynmawr.edu/bb/kinser/Int3.html

regards

Amadeus

There's a nice brain site at:
http://serendip.brynmawr.edu/bb/kinser/Int3.html