Amadeus said:

>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)?

Neanderthals were listed separately in the paper's charts, and a number of
time periods were listed stretching back to 1.8 million years ago, so that
one can make different comparisons at will. The neanderthal data wasn't a
confounding factor here. The reference cited (Ruff, Trinkhaus and Holliday,
1997, Body mass and encephalization in Pleistocene Homo) compiled
measurements from published, peer-reviewed sources of brain and body mass
data up to that point in time. Unless one can point to a more complete
analysis in terms of pulling together a significantly wider range of data,
it appears to be one of the best statements of the evidence as it stands.

>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.

All interesting information -- it doesn't touch the basic point, though.
The key fact to not lose sight of here that the starch hypothesis has to
squarely confront, is that modern living humans' brains are at least 8%
smaller than they used to be. Whatever the exact timeframe of the change
may have been, today's 8 to 11% smaller brains exist in bodies digesting
huge amounts of starch. More than the species has ever eaten before. I
didn't hear an explanation how that could be if the starch theory is
correct.

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

This is another side issue that doesn't have anything to do with the point
under discussion. Granted, brain organization as well as neural connections
are important factors to intelligence as well as size. That's a given,
agreed, and a modern-day high level of human intelligence was already
pointed out in my earlier post. The very reason I did so was to account for
it and note specifically that it is nevertheless immaterial regarding the
issue in contention. Which is brain *size* and its relation to diet.

I wonder though at the apparent dismissiveness here of brain size's
relationship to intelligence. At a certain point, brain size does matter to
intelligence. Nobody argues apes could be as intelligent as humans despite
a smaller brain. Reductio ad absurdum. At what point would we willingly
draw a line and say we don't care if our brain is smaller than it is or
was? 8% 11% 15% 20%? I don't know about anybody else, but I'd sure rather
not give away any myself. A position that would, seems unreasonable to me.
I'll keep what I've got, thank you very much! :-)

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

When comparing different species' brain size, such as elephants to humans,
the scientific standard for doing so is EQ, encephalization quotient, or
brain size relative to body size (proportionality), not absolute size.
Comparatively speaking, elephants have small brains given their body
size/metabolism. (All that metabolism, and such a small brain when stacked
next to it in comparison--life just ain't fair sometimes!)

One interesting point related to this is that while absolute human brain
size has decreased, encephalization quotient (EQ) from 35000 years ago has
remained roughly the same. This would seem to suggest that our genetics for
brain size relative to body size so far haven't changed. Which is as
expected, actually. One wouldn't expect significant genetic evolution to
have occurred in 35000 years, or at least not in just 10000 years, when the
largest brain size decrease occurred. That in turn suggests it is diet
rather than evolutionary forces that are responsible for the recent
decrease. If that is true, then both brain/body size should rebound quickly
back to their full potential if diets species-wide were to go in a paleo
direction. A heartening thought!

If starch or density of energy intake is the biggest dietary factor
responsible for brain growth, then to question everything else but the
starch hypothesis here, when our starch increase is so great today, seems
unreasonable.

I'd be interested in a reasonable explanation. It's a key question for the
Wrangham theory that sorely begs an answer. None has been forthcoming. What
proposal would explain why lesser brain size coexists with such huge
amounts of starch in the human diet today, when prior to agriculture 8-11%
larger brain sizes were prevalent when starch was low by comparison?

Herb