It’s only about half a dozen genetic changes that converted the seeds of a plant that was essentially not useful to people to one of our major food crops. But it was in the 20th century that we saw the huge expansion of the ear. And that came from observations at the beginning of the century made at Cold Spring Harbor, and it’s a little bit of an interesting story.
It was George Harrison Shull who actually was asked to demonstrate the newly rediscovered Mendelian principles who inbred some strains of corn that he got from various places, and then he crossed them. And much to his surprise he suddenly got much bigger, sturdier plants with larger ears. He published a little paper that said, hmm, this might have a some bearing, some implications for agriculture.
Of course it took many more decades before hybrid corn was adopted, and indeed many of the things that people say about genetically modified crops today were said about hybrid corn then. Farmers didn’t want to be compelled to buy seeds over and over again. They didn’t want companies running their business, and so forth. But all that is history.
Of course we’ve done this with wheat. We’ve done it with rice. And we’ve done it with a huge variety of plants, principally increasing the sizes of fruits, making them less toxic, removing the seeds from them, making them healthier such as the Ruby Red grapefruit at the lower right, which was actually created by irradiating shoots of grapefruit at the Brookhaven National Lab and then sending them back to Texas to grow them out and examine for useful mutations.
Molecular biology entered agriculture roughly 30 years ago, and today of course we have the familiar modifications of a number of different crop plants—corn, cotton, with a gene from a bacterium Bacillus thuringiensis. It’s often called the BT gene, but it is a toxin gene which is toxic to insects but not to people. Today genetically modified crops, only a few of them actually, are grown on about 300 million acres in 25 different countries.
There has been a lot of resistance to genetically modified crops in many countries, and I think that one of the things that we need to do today is to reexamine the regulatory process. We have a regulatory apparatus in this country that allows big biotech companies to get crops out to farmers. But I think one of the challenges for us going forward in creating a more sustainable agriculture is to reexamine those regulations in the light of accumulating evidence of the safety of GM crops.