IT’S A THREAT? IT’S A BOON? IT’S . . . SUPERCORN!
Writer’s comment: While interviewing people for this article, I was astonished by how few had heard the term “genetically modified crop.” I wrote this article hoping that the gap in understanding between those with a science background and those without will narrow. More of us should question controversial science, voicing educated concerns that are considered instead of unfounded fears that are ignored. I encourage all readers to continue their education and participation in the debate concerning genetically modified corn. In the words of Albert Einstein, “The important thing in life is never to stop questioning.”
Thanks to Judith Kjelstrom and Tree Kilpatrick for allowing me to inter-view them, my roommates for their editing services, Jayne Walker for her suggestions and for inspiring me to explore writing as a possible career, and my parents for supporting all my wacky adventures.
Instructor’s comment: After discovering the stylistic freedom that comes with first-person reporting, the great majority of my English 104C (Journalism) students have been reluctant to apply these new writing skills to their own academic disciplines. I was delighted to watch Annie Corbett expand her range throughout the quarter. She forged a concise, efficient style for her first article, an op/ed piece arguing that the genetics curriculum should cover the ethical implications of recent research. The real breakthrough came in her profile piece, a delightful account of singing with a gospel choir. All the hard work she put into perfecting the diction, sentence rhythms, and structure of her second article gave her the tools and the confidence to tackle an important issue in her own field, in the style of popular journalism.
“Supercorn” demonstrates that science journalism can be as creative—as exuberant, stylistically—as writing about social issues, travel, or popular culture. I hope Annie’s work will inspire other students to tackle controversial issues with the same spirit of adventure. —Jayne Walker, English Department
—Doris Earnshaw, Comparative Literature
Mmmm . . . corn. For centuries, it has been shucked, broiled, popped, chomped, de-cobbed, and picked out of teeth. Now corn is being transformed at the cellular level. Hold the butter and salt, a new breed’s in town.
The new breed caused panic last year, when a strain of genetically modified corn called Star-Link was found in Taco Bell brand taco shells. Star-Link corn had been approved for livestock, not human consumption, and was promptly recalled from supermarket shelves.
Still, a tremendous amount of biotech corn has been deemed safe for humans to eat. As of 1999, 25% of the corn in the U.S. was genetically modified. Most harbors the gene coding for the insect toxin Bt, taken from Bacillus thuringiensis, a common soil bacterium.
Inserting a gene from a microbe into the genome of a vegetable sounds like science fiction, but it’s actually more like going to war. At twelve days old, corn embryos are drafted into service. They are marched into a biolistics chamber, which contains a “gene gun.” Particles coated in the DNA that codes for the Bt gene penetrate the cell walls of the corn embryos.
Although the technology to make corn expressing the gene for Bt toxin is new, the toxin is not a newcomer to the agricultural scene. Organic farmers have been using it for years. Bt toxin destroys the alkaline gut lining of insects while leaving the acidic gut of other animals, including humans, intact. Bt toxin is a natural insecticide that leaves no chemical residue in the soil.
The main target of Bt corn is the European corn borer. Iowa corn farmers have been known to lose half their crop to its hungry larvae. The borer chomps its way inside the corn stalk, destroying the plant by allowing fungus to blight the kernels. Alas, the plant can’t be salvaged, even as fluffy popcorn.
Inserting foreign genes like Bt toxin into corn is by no means an exact science. Not all corn embryos successfully receive the gene that encodes the Bt toxin. For those that do, it’s a bit like Clark Kent going into a phone booth and coming out as Superman.
But even Superman has his kryptonite.
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The Bt toxin kills other insects besides the corn borer. A study performed at Cornell University found that larvae of the monarch butterfly are also susceptible to its gut melting properties. This discovery caused an uproar among environmentalists.
The larvae dine on milkweed, which often grows around cornfields.
Scientists at Cornell tested whether corn pollen blown onto milkweed plants could harm the monarch larvae. Half of the larvae on the Bt pollen dusted plants perished, compared to the near 100% survival of those in the control group.
These findings have been cited as evidence that extreme caution is needed before novel genetically modified crops are introduced into the environment. But some have raised questions concerning the validity of the research.
Dr. Judith Kjelstrom, Associate Director of the Biotechnology Program at UC Davis, shared her doubts: “It was all done in the laboratory. They just put pollen, tons and tons of pollen, on milkweed, and then they put the caterpillars on them.”
Field tests revealed that the amount of corn pollen found on adjacent milkweed plants was much less than the amounts used in the Cornell study. “Pollen from corn is very heavy. It doesn’t disperse very far from the field. The milkweed was on the edges of these fields,” said Dr. Kjelstrom.
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Pest resistance is another environmental concern. Most of the European corn borers die upon exposure to Bt. But the few that live will be the only ones to reproduce, and they will likely pass on the genetic secrets to surviving our weapon. Bt corn has been lambasted by organic farmers, who fear that an important means of controlling pests will become useless as corn borers gain resistance to the toxin. Resistance is expected in a mere twenty to thirty years.
Tree Kilpatrick, a graduate student in Integrated Pest Management, voiced his concerns: “Organic farmers are selective in their use of Bt. Now, with genetically modified Bt corn, the toxin is a constant presence.”
With constant exposure to the toxin, many borers will die. But those that survive will be resistant to the toxin and will not be exposed to other pest control techniques that organic farmers use to ensure they don’t create resistant strains of insects. Rotating insecticide usage, planting more than one type of crop, and introducing beneficial insects are all effective techniques. Without them, a resistant population of borers in a field of Bt corn will grow at a more accelerated rate than in a field where the farmer uses a variety of means to control the insects.
Bt toxin has been an important natural insecticide for organic farmers. But now that biotechnology companies have scooped up and shoved it smack in the middle of a corn nucleus, it may soon cease to be effective.
Organic farmers can do little, if anything, to control the extent of the Bt toxin’s use. Dr. Kjelstrom says, “This has been their tool. Now big agribusiness is saying, well, we want it as our tool. In a free system, I don’t know if you can tell big business that they can’t use your tool.”
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Genetically modified crops are now patented and owned by biotechnology companies. Kilpatrick, who also works at the UC Davis Student Farm, is wary of the grip big business has on agriculture. “A major risk is commodifying genes in such a way that they can be bought and sold,” he said.
Plant patents have been legal for years. Now these patents can be enforced.
To ensure that their special corn seed cannot be replanted, Monsanto has developed a “terminator gene.” When corn harboring this gene is planted in a field with Monsanto-owned Bt corn, it can theoretically cause seeds to become sterile. Farmers afraid of Monsanto executives unleashing a molecular version of Arnold Schwarzenegger into their cornfield must buy new Bt corn seed every year.
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Farmers in third world countries are lucky if they have any seed to replant. One hope of biotechnology is to improve crop yields in parts of the world where hunger is rampant. Although millions starve every year, there is enough food on this planet for every human to eat 2700 calories per day. Unfortunately, food must be distributed, which is often easier said than done.
Dr. Kjelstrom says, “This distribution issue is not an easy thing to solve. The black market is real. And, as the saying goes, ‘If you give a man a fish, he eats for a day. If you teach him to fish, he eats for a lifetime.’ The whole biotech focus is to give these tools to third world farmers so he can grow his own crops in his own country.”
Some disagree that developing genetically modified crops will solve the problem, and have suggested alternatives.
Says Kilpatrick, “There’s been a lot of PR concerning this distribution issue, but we haven’t explored other methods. We should try to increase the use of effective organic practices like cover crops and composts to save soils and improve fertility, and the use of traditional breeding to increase the performance of staple foods that may be better suited to certain ecological regions . . . like sweet potatoes and cassava. . . . The crops produced so far have been for the first world, and many patents on biotech techniques make it hard for third world countries to do work in biotech. . . . There’s too much focus on potential.”
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In the wake of the Star-Link recall, concerns about environmental and economic impacts have been brushed to the side, as possible health risks associated with eating genetically altered corn have taken center stage. Says Kilpatrick, “Creating new proteins we haven’t eaten is a bad idea. . . . They are possible allergens that could cause reactions by the immune system.”
Food allergies are triggered when our immune systems overreact to certain proteins. New genes in corn, like the Bt toxin gene, give rise to new proteins. Although not all characteristics of allergy-causing proteins are well understood, novel proteins do undergo testing. Our stomachs must have the ability to properly break down the proteins for them to be considered safe. They are subjected to heat and acid to simulate the conditions in our stomachs.
Dr. Kjelstrom says, “It [the testing for allergenicity of genetically modified crops] really is terribly rigorous. Now, is it 100%? No, it’s ‘what’s the probability of this being an allergen?’”
Kilpatrick is wary that the new proteins are not 100% safe. “There is always the potential for things to go wrong. We need to keep the ‘precautionary principal’ in mind.”
Cry 9C, the novel protein found in the Star-Link corn, was slightly more resistant to breakdown than proteins found in other Bt corn varieties. The slight difference in stability prevented Star-Link corn from being approved for human consumption.
Luckily, no allergic reactions as a result of eating Star-Link corn products were reported. Dr. Kjelstrom thinks that genetically modified crops carry the same risks as any other food. “When something new comes in, say the kiwi, from Australia, do you think they test any of that new fruit for allergenicity? They just start selling it. . . . Biotech foods are scrutinized a lot more than some new food products.”
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Genetically modified crops like Bt corn are seen as a boon by some and are feared by others. They have the potential to improve agriculture in developing countries and increase crop yields. They also may upset the balance of ecosystems and cause health problems. The technology is still young, and, as consumers, we must educate ourselves and sort out the facts from the fears. After all, Bt “Supercorn” is already at a supermarket near you.
“Calories Per Capita.” 17 March 2001 http://www.overpopulation.com.
Friedlander, Brian. “Toxic pollen from widely planted, genetically modified corn can kill monarch butterflies, Cornell study shows.” 29 June 2001. http://www.news.cornell.edu/releases/May99/Butterflies.bpf.html.
Kilpatrick, Tree. Personal interview. 10 March 2001.
Kjelstrom, Judith. Personal interview. 14 March 2001.
Pollen, Michael. “Playing God in the Garden.” New York Times Magazine. October 1998: 89-99.
Wheelwright, Jeff. “Don’t Eat Again Until You Read This.” Discover, March 2001: 36-43.