This bothered me, however: Nothing was ever "meant" to be used to control other species. Nothing was ever "meant" at all. I really dislike this mindset that assumes that humans are outside of natural processes. We are a natural process. Even though we make Mountain Dew, we are no less natural than field mice. Many think that we are not a natural process due to religious beliefs. It drives me nuts that many non-religious people think that we aren't a natural process due to some sort of species self-loathing. That is crazy. Warfarin is a blood thinner, and it prevents coagulation. It's used commonly when you stay for an extended period in the hospital to prevent blood clots. As rat poison, too much of it basically makes them hemorrhage, and bleed out. I don't know much about blood diseases, but I wonder if these warfarin-resistant rats could teach us anything that could be used to treat hemophilia.PCBs were never meant to be used to control other species.
The clearest evolutionary change in rats and mice as a result of our interference has been the evolution of resistance to the rat poison warfarin.