Don't ask me how I stumbled across this Atlantic article from 2002. Nor should you read it, if your only interests are Jews, Israel, and the many folks who dislike them both. It's a long article, and Jews aren't mentioned even once, not even as destroyers of nature or something. Nada. Baffling, even: how could anyone write such a long article and not fit us in at all, not even a bit?
On the other hand, it is lots of fun. The thesis of the article is that when the first Europeans arrived in the Americas, back in 1492 and thereafter, they brought lots of germs to which they were partially immune, and the locals not at all. As a result, 90% (!!) of the locals quickly died, often years before the Europeans reached inland; the vast plains with buffalo, for example, hadn't been there for time immemorial. They'd been there a generation or two, moving in and multiplying after men disappeared.
In the Amazon the reality was even more dramatic. The locals were in the process of terraforming the entire area (about the size of Western Europe) when the European illnesses killed them all off.
Is it true? How should I know. Read for yourself and see if it convinces you.