Genetically Modified Foods: Making the Earth Say Beans
GMO Pundit
Nina V. Fedoroff, Evan Pugh Professor and Verne M. Willaman Chair of Life Sciences, Penn State
June 23, 2007
Excerpt…
In chapter seven of his environmental masterpiece Walden, Henry David Thoreau writes about his bean field: “…making the yellow soil express its summer thought in bean leaves and blossoms rather than in wormwood and piper and millet grass, making the earth say beans instead of grass—this was my daily work.”
You may wonder why I begin an essay on genetically modified foods with a quote from Thoreau. But to me, environmentalism and plant breeding are inextricably linked. Our civilization rests on our ability to make the earth say beans. Other creatures feed their young, but the adults of most species fend for themselves, spending much of their day doing it. By contrast, we humans have learned to farm. Over the last few centuries, advances in science have let fewer and fewer farmers feed more and more people, freeing the rest of us to make and sell each other hats and houses and computers, to be scientists and politicians, painters, teachers, doctors, spiritual leaders, and talk-show hosts. In some parts of the world, only one person in a hundred grows plants or raises animals for food. Most of us are surprisingly unaware of what it takes to create our bread and breakfast cereal, pasta and rice, those perfect fruits and vegetables, unblemished by insect bites or fungal spots. Free to live our lives with little thought for our food, we ignore the source of the gift.
Our civilization rests, in fact, on a history of tinkering with nature—on making the earth say beans instead of grass. Thoreau’s beans were not wild. The pod of a wild bean bursts when its seed is ripe, flinging the bean far from the parent plant to find a new place to sprout. The pods of those beans we grow for food do not burst. Such beans can no longer seed themselves. Nor can the wild grasses we have changed, over the millennia, into our staple food sources: rice, wheat, and corn. To change a wild plant into a food plant requires changes in the plant’s genes. To boost its yield, to make the earth say more beans, means changing the plant’s genes, as well. For thousands of years, farmers have been picking and choosing plants, propagating those with the genetic changes—mutations—that made them better food plants. Our civilization is the beneficiary of this genetic tinkering.
I have been studying plant genes—and tinkering with them—since the early 1980s, when I had the good fortune to work with Nobel Laureate Barbara McClintock, whose discovery of “transposons,” popularly called “jumping genes,” rewrote our concept of a gene. By identifying and cloning a jumping gene in 1984, I was able to identify the DNA sequences of McClintock’s transposons and then to analyze and understand how they operate. Today we know that the genome is full of transposable elements and is constantly changing. Instead of being static “beads on a string,” genes can move from one chromosome to another. Although the genes themselves are conserved over long evolutionary periods, there have been, and continue to be, numerous rearrangements, transpositions, duplications, and deletions, many of which are the work of the restless transposons.
McClintock and I worked on corn, and since then I and my students have used many of the techniques of genetic engineering invented in the last 20 years to uncover the secrets of how transposons and other kinds of plant genes work. I have never applied my knowledge to making a genetically modified crop, but my familiarity with both the techniques and the corn genome made me pay attention when corporations began doing so—and when the federal government began regulating the field-testing and marketing of these crops. I have given numerous public lectures on genetically modified foods and, with co-author Nancy Marie Brown, have written the book Mendel in the Kitchen: A Scientist’s View of Genetically Modified Foods, published in 2004 by Joseph Henry Press, an imprint of the National Academies Press….
Full article at GMO Pundit and the Penn State Science Journal.
