If you really want to get technical, the very concept of Native Americans is a falsehood as humans were never native to North or South America. As much as I respect the various tribes of these two continents[my wife is actually part Mohawk], like the rest of us, they are what would technically be considered an invasive species, they merely arrived first. And there is paleontological and archaeological evidence that their arrival did have a negative environmental impact on various native species, though they did eventually reach an equilibrium with native wildlife before colonists from elsewhere began arriving.
