Craig Coonrad wrote:

> That's a bunch of poo poo IMHO.
>
> If the theory that eating starchy tubers increases brain size, then
> naturally horses and cows should be highly intelligent. The most
> ingelligent animals seem to be meat eaters (i.e. dolphins, orcas,
> chimpanzees, the naked ape).

Craig, did you read the Articles of Richard Wrangham ("Out of the Pan,
Into the Fire" and "The raw and the stolen")? I once found it on the
net. It's quite thought provoking :-)

To your comment: horses and cows are herbivores. In nature they don't
eat starchy food, the eat grass. Grass is high protein (relative to
carbohydrate) but low density.
Wrangham's theory is concerned with carbohydrate availability in high
density. Provided by tubers, best by cooked tubers.

The most intelligent animals are (undoubted?) the big apes (chimps,
gorillas, orangs, bonobos...). These are fruit-eaters or herbivores.
Whales (including dolphins, orcas, blue whales etc) have *big* brains,
therefore they are accredited a high intelligence. They are eating fish
or plancton (depending on their size). Do they compare well to birds
(e.g. parrots) in intelligence?
Are sharks very intelligent? Cats? Tigers?

The brain of a chimp is 1/3 or 1/4 the size of a human, relative to body
size. This bigger brain has a 4-fold bigger demand of *energy*, not of
protein. And that energy needs to be carbohydrate.
How can a big ape, say australopithecus africanus,  1.9 mio years ago
satisfy the 4-fold carbohydrate demand? Easy: more fruit. But in the dry
ice age with less fruit? There are the tubers. Cooking greatly increases
the energy availability of these.

Those who suspect an increased carcass eating as a keypoint of brain
enlargement can only point out that the mass of the brain consists of
about 1gram more *long chain fatty acids* (~ 1% of 1 kg more brain). And
suspect that this "mass" can easily be eaten be eating animal *brains*.
And suggest that this lcFA couldn't be self-synthesized by the human
child (which is absurd since many human childs do grow up normally
without ever eating brains or cold water fish).
Dr.Cordain's theses go the same path btw.

> Carbohydrate energy is short lived compared to protein energy. .. I think
> it's that slow burning protein that sustains our bulbous brains.

The brain needs somewhat 500kcal per day. That would be 500g Rabbit per
day or 115g protein. Did humanity eat that 500g of additional meat
everyday? I mean in addition to 2000 more kcal for the rest of the body?
I remember that energy from protein is limited by the excreting capacity
of the kidneys.
Carbohydrate energy is not short lived. Some forms of it (sugar) enter
into the body with an unhealthy *speed*. What is not used immediately is
stored into glycogen or fat. Accidentally  the glycogen stores last for
about 1 day, or 4 days for the brain if enough fat is present.
Enough time to come from one meal to the next.

>.. The naked, frail homo sapiens has no poison, no fangs, no protective
> exoskeleton and we're pretty darn slow. It's up to our trusty cerebral
> cortex to save the day!

But the human can survive in the hot african day, when the predators
sleep. And safely collect tubers (or carcasses).
A large brain with many neurons lasts better than a small one in the
heat. This is my idea of an evolutionary driving force to brain
enlargement. Actually based on a similar idea of a scientist I once
heard of.

regards

Amadeus