Hi Philip;

"I wouldn't start with any of those, though they are all clues to consider. I
would start with trying to figure out what our species, homo sapiens,
generally ate when it was in its natural environment in the wild and
semi-wild (its "primitive" state). Based on evolutionary theory, the key
starting point to look at would seem to be the period during which our
species developed, though earlier periods would provide some relevant
information as well. "

Trying to figure out what they at would be guesswork though?

> Does meat-eating increase life-span or brain-size? 

"There is a hypothesis that it contributed to the evolution of larger hominid
brains, but it is hotly debated. Whether meat added to life-span, I don't
know. Meat does seem to improve fertility and increase co-operation in
mostly plant-eating primates like chimps, based on the work of Goodall,
Leakey and others. "

My impression is that meat eating increases size: look at the grizzlies of the northwest that eat salmon. They are the largest bears on the continent sometimes even exceeding the weights of polar bears. I would suppose that larger brains indicate generally greater intelligence  - but what I recall reading, is that the numbers of folds determines IQ. (I guess surface area is more important). 

"Leakey thinks that the cooperation that hunting and
sharing of meat required and encouraged was more important in the
development of humans than the    "

The end of this post  (and another one) got cut off here.... (maybe it is my mail server, since no one else seemed to have indicated the same)....

Marilyn