Dr. Barbara Doyle Prestwich:

We all know that herbicides are not just used with genetically modified crops and we use herbicides all of the time. Herbicides have been around for a lot longer than genetic but, somehow, that argument has become kind of confused, if we like. Generally, and very briefly, the science behind herbicide tolerance is that herbicide tolerance is a trait that is exhibited both by plants and by microbes in the soil. With some of the stuff we see in terms of what is happening in the United States, like herbicide-tolerant maize, for example, it may be that a gene has been taken from a microbe and inserted into a plant, and that is one way. There are different strategies and I will not go into all of them, but that is just one way. Again, herbicides are not around because GM crops are around, but the two have been conflated.