>>9127948Answer by Matan Shelomi, Zoologist:
Humans are definitely omnivores.
The best evidence is our teeth: we have biting/tearing/ripping incisors and canines (like carnivores) and chewing molars (like herbivores). Animals with such diverse teeth tend to be omnivores.
Chemically, we lack cellulases or cellulosic symbionts that many herbivores have, and have lots of proteases that carnivores do. But we do have sucrases that let us digest fruits. Humans require vitamin B12 to thrive, which can only come from animal sources or certain bacteria (vegans must supplement their diet). We also require vitamin C, which is present in citrus fruits and organ meat, the latter probably being our evolutionary ancestor’s main source.
Interestingly, we have very powerful livers (the detoxification organ) and a very strong ability to smell rot/decay/decomposition relative to other animals. This suggests we may have evolved as scavengers, eating dead (but not too decayed) carcasses killed by other animals....
