Dr. Strangelunch

Or: Why we should learn to stop worrying and love genetically modified food.

Ronald Bailey from the January 2001 issue

(Page 3 of 4)

Model biosafety legislation proposed by the Third World Network goes even further than the Biosafety Protocol, covering all biotech organisms and requiring authorization "for all activities and for all GMOs [genetically modified organisms] and derived products." Under the model legislation, "the absence of scientific evidence or certainty does not preclude the decision makers from denying approval of the introduction of the GMO or derived products." Worse, under the model regulations "any adverse socio-economic effects must also be considered." If this provision is adopted, it would give traditional producers a veto over innovative competitors, the moral equivalent of letting candlemakers prevent the introduction of electric lighting.

Concerns about competition are one reason European governments have been so quick to oppose crop biotechnology. "EU countries, with their heavily subsidized farming, view foreign agribusinesses as a competitive threat," Frances Smith writes. "With heavy subsidies and price supports, EU farmers see no need to improve productivity." In fact, biotech-boosted European agricultural productivity would be a fiscal disaster for the E.U., since it would increase already astronomical subsidy payments to European farmers.

The global campaign against green biotech received a public relations windfall on May 20, 1999, when Nature published a study by Cornell University researcher John Losey that found that Monarch butterfly caterpillars died when force-fed milkweed dusted with pollen from B.t. corn. Since then, at every anti-biotech demonstration, the public has been treated to flocks of activist women dressed fetchingly as Monarch butterflies. But when more-realistic field studies were conducted, researchers found that the alleged danger to Monarch caterpillars had been greatly exaggerated. Corn pollen is heavy and doesn't spread very far, and milkweed grows in many places aside from the margins of cornfields. In the wild, Monarch caterpillars apparently know better than to eat corn pollen on milkweed leaves.

Furthermore, B.t. crops mean that farmers don't have to indiscriminately spray their fields with insecticides, which kill beneficial as well as harmful insects. In fact, studies show that B.t. cornfields harbor higher numbers of beneficial insects such as lacewings and ladybugs than do conventional cornfields. James Cook, a biologist at Washington State University, points out that the population of Monarch butterflies has been increasing in recent years, precisely the time period in which B.t. corn has been widely planted. The fact is that pest-resistant crops are harmful mainly to target species-that is, exactly those insects that insist on eating them.

Never mind; we will see Monarchs on parade for a long time to come. Meanwhile, a spooked EPA has changed its rules governing the planting of B.t. corn, requiring farmers to plant non-B.t. corn near the borders of their fields so that B.t. pollen doesn't fall on any milkweed growing there. But even the EPA firmly rejects activist claims about the alleged harms caused by B.t. crops. "Prior to registration of the first B.t. plant pesticides in 1995," it said in response to a Greenpeace lawsuit, "EPA evaluated studies of potential effects on a wide variety of non-target organisms that might be exposed to the B.t. toxin, e.g., birds, fish, honeybees, ladybugs, lacewings, and earthworms. EPA concluded that these species were not harmed."

Another danger highlighted by anti-biotech activists is the possibility that transgenic crops will crossbreed with other plants. At the Congressional Hunger Center seminar, Mae-Wan Ho claimed that "GM-constructs are designed to invade genomes and to overcome natural species barriers." And that's not all. "Because of their highly mixed origins," she added, "GM-constructs tend to be unstable as well as invasive, and may be more likely to spread by horizontal gene transfer."

"Nonsense," says Tuskegee University biologist C.S. Prakash. "There is no scientific evidence at all for Ho's claims." Prakash points out that plant breeders specifically choose transgenic varieties that are highly stable since they want the genes that they've gone to the trouble and expense of introducing into a crop to stay there and do their work.

Ho also suggests that "GM genetic material" when eaten is far more likely to be taken up by human cells and bacteria than is "natural genetic material." Again, there is no scientific evidence for this claim. All genes from whatever source are made up of the same four DNA bases, and all undergo digestive degradation when eaten.

Biotech opponents also sketch scenarios in which transgenic crops foster superpests: weeds bolstered by transgenes for herbicide resistance or pesticide-proof bugs that proliferate in response to crops with enhanced chemical defenses. As McGloughlin notes, "The risk of gene flow is not specific to biotechnology. It applies equally well to herbicide resistant plants that have been developed through traditional breeding techniques." Even if an herbicide resistance gene did get into a weed species, most researchers agree that it would be unlikely to persist unless the weed were subjected to significant and continuing selection pressure-that is, sprayed regularly with a specific herbicide. And if a weed becomes resistant to one herbicide, it can be killed by another.

As for encouraging the evolution of pesticide-resistant insects, that already occurs with conventional spray pesticides. There is no scientific reason for singling out biotech plants. Cook, the Washington State University biologist, points out that crop scientists could handle growing pesticide resistance the same way they deal with resistance to infectious rusts in grains: Using conventional breeding techniques, they stack genes for resistance to a wide variety of evolving rusts. Similarly, he says, "it will be possible to deploy different B.t. genes or stack genes and thereby stay ahead of the ever-evolving pest populations."

The environmentalist case against biotech crops includes a lot of innuendo. "After GM sugar beet was harvested," Ho claimed at the Congressional Hunger Center seminar, "the GM genetic material persisted in the soil for at least two years and was taken up by soil bacteria." Recall that the Bacillus thuringiensis is a soil bacterium-its habitat is the soil. Organic farmers broadcast B.t. spores freely over their fields, hitting both target and nontarget species. If organic farms were tested, it's likely that B.t. residues would be found there as well; they apparently have not had any ill effects. Even the EPA has conceded, in its response to Greenpeace's lawsuit, that "there are no reports of any detrimental effects on the soil ecosystems from the use of B.t. crops."

Given their concerns about the spread of transgenes, you might think biotech opponents would welcome innovations designed to keep them confined. Yet they became apoplectic when Delta Pine Land Co. and the U.S. Department of Agriculture announced the development of the Technology Protection System, a complex of three genes that makes seeds sterile by interfering with the development of plant embryos. TPS also gives biotech developers a way to protect their intellectual property: Since farmers couldn't save seeds for replanting, they would have to buy new seeds each year.

Because high-yielding hybrid seeds don't breed true, corn growers in the U.S. and Western Europe have been buying seed annually for decades. Thus TPS seeds wouldn't represent a big change in the way many American and European farmers do business. If farmers didn't want the advantages offered in the enhanced crops protected by TPS, they would be free to buy seeds without TPS. Similarly, seed companies could offer crops with transgenic traits that would be expressed only in the presence of chemical activators that farmers could choose to buy if they thought they were worth the extra money. Ultimately, the market would decide whether these innovations were valuable.

If anti-biotech activists really are concerned about gene flow, they should welcome such technologies. The pollen from crop plants incorporating TPS would create sterile seeds in any weed that it happened to crossbreed with, so that genes for traits such as herbicide resistance or drought tolerance couldn't be passed on.

This point escapes some biotech opponents. "The possibility that [TPS] may spread to surrounding food crops or to the natural environment is a serious one," writes Vandana Shiva in her recent book Stolen Harvest. "The gradual spread of sterility in seeding plants would result in a global catastrophe that could eventually wipe out higher life forms, including humans, from the planet." This dire scenario is not just implausible but biologically impossible: TPS is a gene technology that causes sterility; that means, by definition, that it can't spread.