I'm not a scientist, but I would argue, based on the data that I've seen, that GMOs have played a significant impact on crop yields over the past 15 years. I'll allude to a couple of examples and then I'll pass it over to Mike.
One example comes from here in Ontario. If you look at years prior to the introduction of GMO corn to Canadian farmers, farmers were realizing about 112 bushels an acre, on average. Back in the 1930s, you were looking at 30 or 35 bushels an acre. So yes, you saw a lot of improvement. But if you look at the last 15 years, and you look at it proportionately, now farmers are getting nearly 160 bushels an acre with GMO varieties.
Also, there is a European example with Bt corn. These are Monsanto's studies, so we had U.S. third parties. We looked at data over the last 10 years of various Bt corn versus conventional varieties. And it was clear that on average over those 10 years there was a gain of half a metric tonne per hectare over the conventional GMO varieties.
So I'm not a scientist by background, but those are data points that I see as working well.