I will agree with you that humans evolved as hunter gatherers, but these days hunting is not needed. And the deer overpopulation thing is not what it seems. I was reading an article just the other day about how hunters, with the help of Fish and Game, which gets a lot of its income through hunting licenses, have more or less conspired to overbreed deer just so they can have the exquisite pleasure of slaughtering them. Yes, we have killed off a lot of their natural predators, but that's not the only factor. Maybe I'll do a xombyte about it. This deer issue is too convoluted for a comment here, and I apologize for taking over your xombyte with animal issues. I'm not even sure how this started! ;)

People can certainly adapt to it, especially in the 21st century, even "high in the mountains of Tibet!" And those who choose to be vegans are not "sheltered", as you suggest(what a strange concept!)--in fact, vegans are all too aware of what's going on in the world, i.e., that humans are exploiting animals for their own self-interest and putting undue pressure on the environment--and we're doing something about it, unlike animal eaters. But unfortunately, meat has become tied to affluence, and, for example, the rising middle class in China and India are now demanding a steady supply of meat to reflect their greater buying power and higher social status. Inevitably this demand will lead to even more environmental degradation, and ultimately, the good news is that everyone on the planet will have to cut down or eliminate their animal eating and turn to a more plant-centered life. So the situation will, I believe, correct itself, maybe not in my lifetime, but at some point.