The shift to an animal-specialized omnivore diet significantly drove the expansion of the human brain.

“the hypothesis I advanced in the first chapter of the book is that human brain size increased rapidly because of our consumption of animals that eating animals made us human not fire that didn't come along for at least another million years but it was eating animals that made us human”

“it is interesting to note that that within anthropology it's not really debated that it was the animal eating branch of human evolution that persisted that changes were happening that something about our environment obviously we came from primates that were eating more plants or a lot of plants and something about our human environment really selected for us to eat more meat”

“the human brain expanded massively and i think there are lots of lines of evidence and you and i have talked about this suggesting that a big part of this shift or perhaps the major spark in this shift in the size of the human brain was our shift from a plant specialized omnivore to an animal specialized omnivore”

“but something happened and we shifted from being herbivorous omnivores to animal based omnivores i would even say carnivorous omnivores who eat the majority of their diet as animals and that many trace to the origin of our rapidly expanding brain”

“we have herbivorous omnivores as our lineage but something happened and we shifted from being herbivorous omnivores to animal based omnivores”