Reasons for not being a vegan

Our brain is considerably larger than that of any monkey. Looking at the records from hominid fossils to modern humans, we see a remarkable increase in brain size from 375-550 ml at the time of Australopithecus, for the 500-800 ml of Homo habilis, 775-1,225 ml of Homo erectus, and 1350 cc in modern humans (Homo sapiens).