The Ecological Risks ofEngineered Crops
Stolen Harvest: The Hijacking of the Global Food Supply
Genetically Modified Pest-Protected Plants: Science and Regulation
If the nineteen recent books and fifteen-pound stack of articles that confront me as I write are any measure, then nothing is more productive of food for thought than thoughts about the production of food. The introduction of methods of genetic engineering into agriculture has caused a public reaction in Europe and North America that is unequaled in the history of technology. Not even the disasters at Three Mile Island and Chernobyl were sufficient to produce such heavy and effective political pressure to prohibit or further regulate a technology, despite the evident fact that uncontained radioactivity has caused the sickness and death of very large numbers of people, while the dangers of genetically engineered food remain hypothetical.
It is out of the question to review this vast literature in its entirety, so I have chosen four recent characteristic examples from the pile. One is a report and set of recommendations from the font of American scientific legitimacy, the National Academy of Sciences/National Research Council. A second, The Ecological Risks of Engineered Crops, is a partisan but temperate case for the dangers of genetic engineering in agriculture, produced under the auspices of a long-established political action group, the Union of Concerned Scientists. The third, Stolen Harvest, is an unremitting indictment of genetic engineering, on moral, cultural, and economic grounds, especially as it applies to the third world. The fourth, Pandora’s Picnic Basket, is the only example I could find of the opposite prejudice. It is a defense of genetic engineering in agriculture and a bitter attack on the apparatus of government regulation written by an agricultural scientist, an inventor of transgenic varieties whose life was made difficult by government regulation.
Whatever fears I might have of possible allergic reactions to food produced from genetically modified organisms, they are not more unsettling than the allergies induced in me by the quality of the arguments about them. What are we to make of a major issue of science and public policy in which a physicist bases her opposition to genetic engineering on “the recognition in the Isho Upanishad that the universe is the creation of the Supreme Power meant for the benefits of (all) creation”1; or a professor of agricultural economics who, in the course of trying to convince us that technology is good for farmers, conveniently makes the elementary error of confusing total household income of farm families with income from farming2; or a senior research scientist working in plant breeding at a major public university who ridicules the need for regulatory oversight of new kinds of foods by citing the introduction of macaroni and cheese on a stick that was announced in his local newspaper3? And these examples are, alas, characteristic of what has been written. Even the most judicious and seemingly dispassionate examinations of the scientific questions turn out, in the end, to be manifestoes. We are presented with a paradigm of Julien Benda’s trahison des clercs; but The Treason of the Intellectuals was concerned with the corrupting effects of ideological passions on intellectuals. Ideological passions about potatoes? It gives one to think.
The uproar about so-called genetically modified organisms (GMOs) has been the direct consequence of the development of a radically new way to manipulate heredity. Human beings have been genetically modifying organisms since the first domestication of plants and animals. The results of those ancient modifications have been organisms that are not only very different from their wild ancestors, but are in many characteristics the very opposite of the organisms from which they were derived. The compact ear of maize with large kernels adhering tightly to the cob is very useful in a grain that needs to be gathered and to be stored for long periods, but a plant with such a seed head would soon disappear in nature because it could not disperse its seed. The history of domestication is precisely the history of the genetic modification of organisms to make them most “unnatural.”
Until recently the method for producing new varieties of plants or animals has been to search for desirable variants and to propagate them selectively. The naturally occurring variation within species can also be augmented by matings with closely related species that do not ordinarily interbreed in nature, but will do so under conditions of domestication. So classical methods of plant and animal breeding have included “unnatural” transgression of species boundaries. But the use of the genetic variation available only from closely related organisms limits what can be accomplished precisely because they are closely related and therefore quite similar. Moreover, introducing genetic variation by crossing between organisms is imprecise. A cross between two varieties is indiscriminate in the hereditary characteristics that are transmitted. Thus if one attempts to introduce disease resistance into an especially high-yielding variety of wheat by crossing that variety with one that has the disease resistance but not the high yield, the result will be a variety with improved resistance but lower yield. The ideal of the plant or animal engineer is to be able to remake the heredity of an organism to order, so as to produce just those variants that the occasion seems to require.
Apparently the secret of genetic engineering was known to the ancients. Genesis 30 tells us that in order to retain the services of his son-in-law Jacob, who was apparently quite good at animal husbandry, Laban agreed to let him keep all the speckled and streaked goats and sheep that were born in the flocks that he tended. Jacob, the ur-biotechnologist, then peeled some twigs to make them speckled and streaked and held them up before the eyes of the plain-colored ewes just as they were about to conceive. This produced the desired result and Jacob became very rich indeed.
Being of little faith, we seem to have lost the twig trick, but have invented a new one. Modern genetic engineering consists in extracting the DNA corresponding to a particular gene from a donor organism and then inserting it into the cells of a recipient in such a way that it becomes incorporated into the recipient’s genome. This insertion can be carried out by coating tiny metal particles with the DNA and shooting them into the recipient cells or by first putting the DNA into microorganisms and then infecting the recipient with them. If the source of the DNA is a distant species that cannot be intercrossed with the recipient, the engineered result is said to be a transgenic organism. The donor and recipient need not be anything like each other for the trick to work.
Thus the human gene for insulin has been successfully inserted into the genome of bacteria, and these bacteria, grown in industrial vats, are now churning out human insulin for the market. Despite the fears about the human ingestion of the products of genetic engineering, no one appears to be worried about the large number of diabetics who are injecting bacterially produced insulin twice a day. As far as anyone knows, no one has been harmed by this product of genetic engineering; but then, as far as anyone knows, no one has yet been harmed by any product of genetic engineering.
The chief use of transgenic DNA transfers in agriculture up to the present has been to provide crop plants with resistance to insect pests or to make the plants resistant to herbicides used to control weeds. The resistance to insects has been created by in-serting into plants the genes codingfor powerful toxins, the Bt proteins, from a bacterium, Bacillus thuringensis. When insects begin to nibble the plants, they ingest the Bt toxin and die. Resistance to herbicides has also been transferred into a variety of crop plants from bacteria, as well as from a variety of unrelated plants that happen to be resistant to particular chemicals. One of the ironies of the current struggle over GMOs is that advocates of organic farming practices who strongly oppose the introduction of transgenic crops containing the Bt genes have for many years promoted the dusting of the bacteria themselves on plants as an organic substitute for chemical insecticides.
While an irony, it is hardly the contradiction that proponents of GMOs suggest. The dusting of a toxin on the outside of plants, from which it could be washed away, is not the same thing as having the plants manufacture it internally. Although pest and herbicide resistance have been the main focus of transgenic engineering until now, anything seems possible. What makes the technique so attractive and so productive of anxiety is that any gene in any species can be transferred to any other species. Of course, some of these transfers will be harmful or even lethal to the recipient organism so that no practical use can be made of them; but there are no general rules to tell us what will work.
The critical point is that there is no limit to what could be done if it were worth someone’s while to do it. Hundreds of plant varieties created by genetic engineering have been tested under guidelines approved by federal agencies, and several dozen transgenic varieties are commercially available, including corn, cotton, squash, potatoes, canola, soybeans, and sugar beets. It has only been six years since the first transgenic crops were planted commercially, yet now more than 20 percent of maize acreage in the United States is planted in transgenic corn and worldwide there are about 100 million acres sown in a variety of transgenic crops, including cotton and soybeans.
The usual reaction of the federal government to widespread public agitation about public health and environmental issues is to tinker with already existing regulatory procedures. When scientific questions are involved, federal agencies or Congress will often request that the National Academy of Sciences, through its research arm, the National Research Council, produce an expert report to guide regulatory policy. Sometimes, however, the Academy will act even without such a request. The National Academy of Sciences is a self-perpetuating body of the American scientific elite that provides technical advice to the government. Its leadership, conscious of its legitimacy as a font of supposedly disinterested and expert opinion on scientific questions, will sometimes arrange for National Research Council reports unbidden, on the assumption that their weight of authority will have an effect on public policy.
The NRC has issued, without a formal request, several reports on genetic engineering since 1974, when it became clear that recombinant DNA techniques would be important as tools of genetic research and technology. Three of those reports have been directly concerned with the application of the techniques in agriculture, one in 1987 on the release of GMOs into the environment, one in 1989 on the safe field testing of transgenic varieties, and, in 2000, Genetically Modified Pest-Protected Plants, which includes a discussion of both the environmental issues and threats to human health.