I can harldy believe that some people seem to think that carnivores were vegetarians less than 6000 years ago. Try to feed a lion plants for a month and see if it still lives. According to your view on evolution (or the lack of it) the lion should hardly or not have changed a bit since then and SHOULD be able to feed on plants.
Why DO lions hunt animals and go thorugh all that trouble when plants grow all around them? And why can carnivores die of starvation in areas with enough vegetation to sustain an animal of its size? BECAUSE THEY EVOLVED TO EAT MEAT! Here's a list (of the top of my head) about the lion:
- Teeth/ jaws that hold down prey and cause suffocation
- Intenstines that are shorter than those of herbivores (so the meat doesn't rot inside the body. Plants are more durable: cows have 4 stomaches AND intestines to digest grass)
- Claws that are designed to hold on to moving prey (not seen in herbivores, because they are meant for killing animals and serve no purpose to herbivores)
- The young lions instictively start eating meat (next to drinking milk). Lions don't start eating plants, though no one tells them not to.
- Starving lions can't survive on vegetation (even if their life depents on it)
- Lions communicate with each other in order to surround herds of herbivores and to execute certain tactics that require cooperation. (Hunting skills are only present in carnivores. Its a trade that increases the chance of killing prey. Why would a 'former herbivore' develop this trait?)
All of these things suggest that the lion cannot survive as a herbivore and that the body of the lion had been formed by evolution to be better and better in what it does: Eat meat on the savannah. The suggestion that all carnivores were herbivores a few thousand years ago is simply hilarious. It also makes me wonder why I waste my time here...