https://www.scaruffi.com/news/opin0712.htmlCaveat emptor: Scaruffi doesn't hesitate to let his imagination far surpass his apparent handle on the facts, but hey they are just opinions, so let's not ruin the fun too easily.
"I reached the conclusion that the meat diet started with cannibalism: we ate humans before we ate animals. And cannibalism started with women eating their own children, and children eating their grandparents.
Cats do it all the time: when they cannot afford too many kittens, the mom eats some of them. If she didn't, it would reduce the chances that the others survive. Since they are YOUR children, you don't feel too bad eating them: they are flesh of your flesh, aren't they?
You have to think like a woman of two million years ago, who was pregnant all the time, did not know how to prevent pregnancy nor how to perform abortion, and had to feed many children, often with no male partner to help out.
The tradition of eating old people is documented in many cultures: nothing was wasted, and it would have been silly to waste the flesh of a dead person.
Once you start eating your own family members, it becomes natural to start eating other humans. In prehistory (and even not too long ago) humans from other tribes were not perceived as belonging to the same species: they don't speak my language, their customs are different, they smell different, therefore they are not the same species as me. Killing them and eating them was not any more morally wrong than eating a hamburger today.
The main meal was brains: our brains need a lot of proteins, and another brain gives the highest amount of proteins in the shortest time. Hence the tradition of killing an enemy and eating his brain.
Then cost/benefit analysis made humans realize that humans were difficult and dangerous to kill, whereas many animals were easy to kill and provided almost the same proteins. That's when domestication started: feeding on defenseless cows and goats was a lot safer than feeding on humans armed with spears and axes. That's when cannibalism became a thing of the past, of primitive men. However, it was still practiced (and valued) until recently in many places of the world.
We are living in the first age free of cannibalism in the history of the human species. It's an age just a few decades old. The age of cannibalism lasted several million years. Put things in perspective and, as repugnant as it sounds today, cannibalism can be said to be the norm, and non-cannibalism the abnormality. If some day the whole world becomes vegetarian, you the meat eater will look like a savage but today you think of vegetarians as lunatic people.
There are 1500 animal species that are cannibals, and 75 of them are mammals, and one of them is the chimp, our closest relative. And now you may continue to eat your hamburger."