Colour vision is only found in some plant-eating mammals, such as monkeys, apes & squirrels. It apparently evolved as a way to determine when fruit was ripe. No true carnivore has colour vision – they only see in muted shades of grey.
We have forward facing eyes because our ancestors were tree-living primates. This enables us (and them) to judge depth and distance. Primate binocular vision is much more developed than that of any carnivore – and almost all primates are veggies! If binocular vision was an adaptation to hunting then gorilla’s eyes should’ve migrated to the sides of their heads by now!
Most humans have to eat Vitamin C every day to stay healthy. It is only available from plants. True meat-eaters make their own Vitamin C and could be fatally poisoned if they consumed it in their diet.
Humans have no natural weapons to catch prey. No claws, ineffective teeth, mediocre eyesight, poor sense of smell. Meat-eating in humans has been a form of cultural – not biological or physiological – evolution and it has happened too rapidly for our bodies to adapt.
As soon as an animal dies (i.e. becomes meat) it begins to rot, attracting decomposing bacteria. True meat-eating animals have very strong stomach acid to kill these bacteria. Natural plant-eaters, including humans, have stomach acid 20 times weaker. This means that bacteria in meat often survive to cause food-poisoning. Also meat has be tenderised by cooking to facilitate digestion.
True carnivores have short, thick intestines to extract the nutrients from meat and then quickly expel it before it rots inside their body. Humans have the long, twisted intestines of a typical plant-eater – this encourages the slower breakdown of plant material. Meat sits in the human gut for days – sometimes years – rotting and poisoning the cells around it. This is the main cause of colon cancer.
Enzymes are the chemicals which break down food into small digestible pieces. Our main enzyme is called amylase and it only breaks down starch. Carnivores do not produce this enzyme. Our enzymes are able to digest beans and nuts much more effectively than flesh.
Why we don’t need four stomachs
The only animals with chambered stomachs are the specialised grass eaters (ruminants) like cows and antelopes. Most mammals are plant eaters with guts that generally resemble our own – horses, elephants, fruit bats, rodents, pigs, hippos, kangaroos, rhinos, tapirs, manatees, sloths, rabbits and of course our closest relatives the monkeys and apes.
The myth of canine teeth
True carnivores have huge canine teeth, but many vegetarian mammals also have large canines, so they are not always linked to diet.
Clouded Leopard: CARNIVORE
Muntjac Deer: VEGETARIAN
Langur Monkey: VEGETARIAN
Human: tiny canines!