The news from Mexico stoked fears around the world that genetic engineering is out of control. While Ignacio Chapela and his graduate student David Quist's discovery ignited a firestorm of controversy by scientists who criticized their work, in August a study commissioned by Mexico's National Institute of Ecology confirmed their findings: Transgenic corn genes were in Oaxacan corn. "What is most important about these findings," Exequiel Ezcurra, president of the institute, told the newspaper La Jornada, "is that transgenic creations move quickly into the environment and that it's time to reconsider ways of insuring our bio-security."
Nobody knows for sure what precise variety of transgenes wound up in Capulalpan corn. Dr. Norman Ellstrand, professor of genetics at the University of California, Riverside, and one of the country's foremost experts on corn genetics, says that the corn in Capulalpan could contain any number of characteristics that have been engineered into American corn. Since corn is openly pollinated, he explains, pollen from one plant can blow or be transported in some other way to fertilize another plant. "And if just 1 percent of [American] experimental pollen escaped into Mexico, that means those land races could potentially be making medicines or industrial chemicals or things that are not so good for people to eat. Right now, we just don't know what's in there."
Chances are good, however, according to Ellstrand, that the genes are from Bt corn, a popular US corn variety genetically engineered to produce its own toxins against a pest known as the European corn borer. The borer presents a sporadically serious threat to US and European cornfields but is rare in Mexico. Ellstrand says there would likely be no immediate damaging effects from the presence of Bt corn in Mexico, but what frightens him is how much we don't know: This year, he is researching how long transgenes will persist in native varieties--whether, in fact, they can ever be bred out of the population. This is a question that until now has not even been studied.
At least for the foreseeable future, then, here in the heart of the world's reservoir for genetic diversity of corn will be transgenes developed for the vast rolling flatlands of American corn country--where, in just six years, Bt corn has moved from laboratory petri dishes into one of every five acres of cornfield.
Frank McLain shifts the gears on his 1982 pickup as we drive through his family's cornfields in central Iowa. This land has been in his family for five generations, since it was homesteaded in 1862. "What they passed on to me is the feeling that this land is not just a hunk of dirt that you use and sell," he says, "that a piece of ground is something that should be kept for the next generation; that you're just a steward and you're not just to use it as a tool or as a doormat."
Frank is the first in his family to plant transgenic crops. On the left side of the road, we're passing a field of Bt corn; on the right, Roundup Ready soybeans. Monsanto's Bt corn contains a gene inserted from a bacteria that prompts the plant to produce its own insecticide; when the corn borer eats it, the plant's toxins go to work in its digestive tract, literally blowing up its stomach. It means that Frank has cut in half the amount of pesticides he used to have to apply to his corn. And Monsanto's Roundup Ready soybean seeds have been genetically altered--using a gene from a bacterium--in a way that enables them to resist the application of Monsanto's own herbicide, Roundup. "When I was a kid you'd see grass or other weeds poking up in these fields, and we'd have to go through and chop them out with hoes or shovels or whatever to clean them up manually or mechanically as best we could," Frank explains. "Now it's pretty easy to come in here with a [Roundup] sprayer and accomplish the same thing."
Frank's experience with genetic engineering illustrates both the allure and the potential dangers of the new technology. For many American farmers, genetically engineered crops offer a level of predictability in a business that can rise or fall with a few degrees Fahrenheit each season.