Gary:
>I have read that and it was not entirely convincing, although it certainly
>sounded nice.  I have not analyzed it thoroughly enough to know whether the
>concepts are valid or not, although the logic may be trying to support a
>preconceived notion about protein.  This is likely too simplistic, but what
>about carnivores?  Don't they have quite a bit of "high quality" food?  Why
>are their brains not bursting at the seams?

Tom:
Actually, Gary, it is the logic behind your question that is
simplistic. Carnivores tend to be more encephalized than herbivores
with the same body size. Your logic ignores the major issue -
an issue ignored by the critics of the expensive tissue hypothesis -
of DHA synthesis rates.

The human brain (and animal brains) contain large amounts of DHA,
yet our synthesis rates are low, and DHA levels are lower in
vegans than in those who consume animal foods. [Note: an algae-
derived DHA supplement is on the market, though it is sold
in gelcaps.] Humans are primates, and primates are seen as
generalists. The expensive tissue hypothesis addresses the
issue of how the human brain tripled in size in evolution, yet DHA
synthesis rates are so very low. (If you don't synthesisze the
DHA, it must come from the diet.)

If you question the material re: expensive tissue hypothesis on
Beyond Veg, I encourage you to:

1. Read *all* relevant material on this topic on Beyond Veg;
specifically the following parts of the Comparative Anatomy paper:
all of part 4, the gut morphology section of part 6, and the 2
segments on
EFAs in section 7.

2. Go to a good University library (you are in the Tampa area? try
the library of the University of South Florida), and look up the
references cited.

I would also note that the expensive tissue hypothesis is
controversial
in scientific circles. I plan to expand those sections when I revise
the Comparative Anatomy paper in the future.

Tom Billings