We have domesticated crops over a very long period of time, like tens of thousands of years. And crops get - seeds get carried. Sometimes, if they're very small seeds, they get scattered off trucks. Pollen travels.

In agriculture, people have taken wild plants that can't be eaten by people - and turned them into wonderful food sources. And that's because genomes can change, and people working with plants have picked mutations. Mutations are nothing more than genetic changes.

Myths about the dire effects of genetically modified foods on health and the environment abound, but they have not held up to scientific scrutiny. And, although many concerns have been expressed about the potential for unexpected consequences, the unexpected effects that have been observed so far have been benign.

We've gotten so good at growing food that we've gone, in a few generations, from nearly half of Americans living on farms to 2 percent. We no longer think about how the wonderful things in the grocery store got there, and we'd like to go back to what we think is a more natural way.

Jumping genes are fundamental because they're agents of change. Everybody knows that organisms evolve. What makes them evolve is that their genes are dynamic and in motion. A familiar example is the stripe-y corn - called Indian corn - that you buy in the fall.

In the last century, as we learned more about genes, we were able to devise ways of accelerating evolution.

We wouldn't think of going to our doctor and saying 'Treat me the way doctors treated people in the 19th Century', and yet that's what we're demanding in food production.