That's not what I'm suggesting. Biodiversity of the expanse of cornfields in the US could have significance for non-farmland, which could mean the spread of certain parasites, diseases, or a change in the susceptibility of them. I'm not much persuaded by saying that it's already ruined, because things can always be improved or made worse. The point is, we just don't know what the effects are and will be. They might be worth the increased yield, but that remains to be seen as we don't yet know the costs. GMO can be powerful, and I don't have a strong opinion on all aspects of it. But, because of the unknowns, IMO it should be carefully studied, and regulated. People are right to be skeptical. We used to use X-rays in shoe stores. Mistakes in the application of new technologies have been made. I am sure we are making some now.But the decreasing biodiversity of a cornfield has very little to do with the extremely high extinction rates, I suspect.