In a Science news article, Swapping Guts for Brains
, Ann Gibbons relates that our carnivorous ancestor's changing diet was , palaeoanthropologically speaking, a Good Thing --
The idea that as our ancestors began to eat more meat, they took in enough calories at each meal to permit their guts to shrink, saving energy from digestion that in turn helped fuel the brain, is getting new support from studies of birds, fish, and primates.
While Technology Review notes an important corollary to Harvard primatologist Richard Wrangham's theory of the consequences of the dawn of cooked cuisine:
human teeth got smaller and duller at around this time, which is the opposite of what would have happened if people had had to rip and chew lots of raw meat
This may have profound evolutionary consequences. If Green Vegans averse to CO2 ban the barbecue, and reverse the million year dental trend ,forcing posterity to adoptively devolve on a diet of raw peanuts and soybeans on the half shell-- behold the face of Homo Vegetans: