Human traits:

1. Our jaw moves side-to-side.
2. We lack non-technological weapons.
3. Our small intestine is 10-12 times our body length.
4. Our stomach capacity is ~25% of our total gastrointestinal tract volume.
5. Our stomach has a pH of 4-5 with food.
6. Our liver cannot detoxify vitamin A.
7. Our urine is moderately concentrated.
8. Our colon is long and sacculated.
9. We can suffer from atherosclerosis.
10. We partially digest food in our mouth with saliva and through extensive chewing.
Traits of omnivores and carnivores:

1. Their jaws move only up-and-down.
2. They have biological weapons capable of attacking, maiming, and killing.
3. Their small intestines are less than 5 times their body lengths.
4. Their stomach capacities are 60-70% of their total gastrointestinal tract volumes.
5. Their stomachs have a pH of <=1 with food.
6. Their livers can detoxify vitamin A.
7. Their urine is extremely concentrated.
8. Their colon is short, simple, and smooth.
9. They do not suffer from atherosclerosis, their bodies process all dietary cholesterol.
10. They swallow food whole or do basic crushing.


note: Because of the small size of our stomach, we eat more frequent and smaller meals.
Our omnivorous and carnivorous animal friends can kill rarely, feasting when they do, storing much of their prey's flesh in their stomach.

See The Comparative Anatomy of Eating by Milton R. Mills, M.D. for more extensive reading.

Back