Pat,
I read the article and I have some issues with it:
For one, we don't know that without eating meat man would NOT have survived as a species. I don't like the speculative premise of the "success" of man being attributed to meat eating. Meat eating might have allowed man procreate faster but that doesn't mean that without meat he would have died off or that he would not have expanded his geographical boundaries. This would have happened regardless whether he ate meat or not as that is the natural progression when food in a specific area can no longer support the population of that area.
I would think that when man went to an agrarian society his life and health would have increased,this, not his meat eating, is the main factor establishing the marked difference in his success.
As for the premise that man's brain size increased indirectly because he ate meat is a reach. There are so many variables that could contribute to his brain size increase that to site one condition is simply biased opinion. We could as easily say that man's brain size increased when he started making crude tools to extract roots from the ground or making and maintaining fire.
"Do Primitive Peoples Really Live Longer?"
Posted on August 2, 2006 by Joel Fuhrman
"No. For example, Inuit Greenlanders, who historically have had limited access to fruits and vegetables, have the worst longevity statistics in North America. Research from the past and present shows that they die on the average about 10 years younger and have a higher rate of cancer than the overall Canadian population.1
"Similar statistics are available for the high meat-consuming Maasai in Kenya. They eat a diet high in wild hunted meats and have the worst life expectancy in the modern world. Life expectancy is 45 years for women and 42 years for men. African researchers report that, historically, Maasai rarely lived beyond age 60. Adult mortality figures on the Kenyan Maasai show that they have a 50% chance of dying before the age of 59.2
We now know that greatly increasing the consumption of vegetables, legumes, fruits, and raw nuts and seeds (and greatly decreasing the consumption of animal products) offers profound increased longevity potential, due in large part to broad symphony of life-extending phytochemical nutrients that a vegetable-based diet contains. By taking advantage of the year-round availability of high-quality plant foods, we have a unique opportunity to live both healthier and longer than ever before in human history."
1. Iburg KM, Bronnum-Hansen H, Bjerregaard P. Health expectancy in Greenland. Scand J Public Health 2001;29(1):5-12. Choinere R. Mortality among the Baffin Inuit in the mid-80s. Arctive Med Res 1992;51 (2):87-93.
Certainly today a vegetarian diet is a healthier diet. Lower cancer rates, longer life, etc. And there is no question a vegetarian diet is better for the planet. So what is this 'study' affording us? Faster procreation? We don't need that with 6.9 billion people on the planet!
Rob
Whether folks "live longer" is not nearly as interesting from an evolution basis than whether they reproduce longer, and the children's chances of reproduction are increased. Child mortality was very high in the past, and getting a child to weaning is a very large energy investment. Uterine involution is slowed considerably, no doubt.
I was watching "Blue Planet" yesterday, even that show brings up what I have attempted to bring up here. It is not new. Heck, there are a few species that the mother offers her own body as the first meal for the offspring. Not common in herbivores, obviously. But many herbivores are hidden carnivores, depending on whether you consider bacteria an animal or a plant. I think current classifications consider them other.
Cattle get a volatile fatty acid fix directly through the rumen wall, but they mostly digest bacteria, which themselves are the entities which digest the grasses, since cattle, like humans, don't have an enzyme which can break down cellulose.
One interesting thing I saw, too...coral are animals, and but get ~98.5% of their nutrition from the sun, because plants are built into them. By day they get their energy from their on-board plants, but at night, they expose themselves further and try to be omnivores. The fact that they do this for the ~2% additional energy should suggest the importance of even small energy and protein increases. Why would they do this, don't coral "know" that vegetarian diet is all they need? No, their genes tell them to do this, because that trait is likely helpful, but surely not harmful to their genes' survival. Small energy and protein increases make all the difference. Coral don't kill other coral by wasteful means, they extrude their own gut onto the competing coral, and digest them in place, withdrawing there gut later, leaving bleached minerals where there was previously competing coral.
In short, I think you are giving too much value to non-reproductive longevity, and too little value to the critical importance of even tiny increases in energy and protein take-up "as the ages roll."