One other very important thing to remember is that the great potato famine occurred because the Irish had decided that one type of potato was all they needed to grow. Once something new attacked it, they lost everything, had there been some genetic diversity among the potatoes being grown, there is a convincing argument that the famine never would've happened. Think we only need one super breed of corn, potato, tomato, etc.? This argument is what Monsanto is selling farmers throughout the world.
If Monsanto thinks they can outsmart nature, then they should look into the most recent medical conundrum involving antibiotics and gonorrhea.