Quote:
Originally Posted by Wolf 335
We didn't evolve into omnivores, we just chose to eat meat.
Our digestive system is not designed for meat, but rather plant based diet.
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Uhhhhhh, I don't agree and neither do many, many scientists:
https://www.google.com/search?source....0.nRb99KC9Ev8
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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.
Lastly, our closest evolutionary relatives, the chimpanzees, are omnivores. The leading theory as to how humans evolved is that we became long-distance runners and hunted food by running it down until it tired, and that our access to meat and protein enabled our brains to evolve further than otherwise. So meat-eating is in our history as well as our DNA and physiology...
https://www.forbes.com/sites/quora/2.../#108c4ecb7af5
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As a new study in Nature makes clear, not only did processing and eating meat come naturally to humans, it’s entirely possible that without an early diet that included generous amounts of animal protein, we wouldn’t even have become human—at least not the modern, verbal, intelligent humans we are.
It was about 2.6 million years ago that meat first became a significant part of the pre-human diet, and if Australopithecus had had a forehead to slap it would surely have done so. Being an herbivore was easy—fruits and vegetables don’t run away, after all. But they’re also not terribly calorie-dense. A better alternative were so-called underground storage organs (USOs)—root foods like beets and yams and potatoes. They pack a bigger nutritional wallop, but they’re not terribly tasty—at least not raw—and they’re very hard to chew. According to Harvard University evolutionary biologists Katherine Zink and Daniel Lieberman, the authors of the Nature paper, proto-humans eating enough root food to stay alive would have had to go through up to 15 million “chewing cycles” a year...
http://time.com/4252373/meat-eating-veganism-evolution/