Re: "but it's ethically wrong to do this from an evolutionary perspective"
@Fibbles - true, nicotine production originally evolved as protection against insects, but this doesn't invalidate Arnaut's point, "the only difference is we know we're doing it".
Should we do it? Depends on the risk analysis, but it is probably easy to wipe out a large, slow-breeding species like mammoths than something that works on humans like myxomatosis works on rabbits if things go pear-shaped. (icon - "Take off and nuke it from orbit...")