1Reading 33-2READING 33-2Source: Heppenheimer, T.A. 2003. The growth of genetically modifi ed foods. Invention & Technology 19(1):16–25.The Growth of Genetically Modifi ed FoodsEven before they Arrived on Consumers’ Plates, they Showed Great Promise—and Attracted Great OppositionOne morning in May 1994, a pair of letters rolled off a fax machine in the offi ces of Calgene, a start-up company located in Davis, California, amid the lush agricultural country of the Central Valley. The letters came from the federal Food and Drug Administration (FDA), and they granted regulatory approval for Calgene’s fi rst product, a genetically modifi ed tomato. Anticipating this decision, company offi cials had already laid in a supply of their new Flavr Savr variety, which combined vine-ripened taste with fi rmness for ease in transport. Three days later, the tomatoes went on sale at a local supermarket. Each Flavr Savr tomato carried a label, while bright-red brochures promised “Summertime Taste...Year Round!”The company’s marketing efforts immediately ran headfi rst into Jeremy Rifkin, a long-standing scourge of biotechnology. Vowing to fi ght a “tomato war,” he declared that Americans were “moving in the direction of organic, healthy, sustainable foods” and had no interest in “gene-spliced tomatoes.” In an interview, he threatened to “picket markets, hand out notices to consumers, and organize ‘tomato dumpings’ and boycotts.” His Pure Food Campaign had chapters around the country that were ready to follow his lead.The day the Flavr Savr tomatoes went on sale, Pure Food activists arrived, carrying a cardboard coffi n and tossing in tomatoes of their own. This protest only attracted more Customers: The day after the demon-stration, the store sold twice as many. For the fi rst time, a gene-spliced food had been offered for sale to the public—and the public had liked it. This was a hopeful step for scientists working in the new technology of genetic engineering, which promised to change the basic characteristics of foodstuffs.Throughout recorded history, farmers and agronomists have been improving their crops with the con-ventional methods of plant breeding. Cross-pollination, grafting, and other techniques have yielded countless new varieties of agricultural products with larger yields, hardiness, disease resistance, and other desirable characteristics. During the 1960s Norman Borlaug launched the Green Revolution, which greatly reduced hunger in Third World countries, by creating high-yielding varieties of wheat and rice.Generic engineering has greatly expanded the potential benefi ts of plant science, making Borlaug (the 1970 Nobel Peace Prize laureate) one of its most enthusiastic proponents. Yet the need for caution has increased as well, for genetic engineering differs from earlier methods as much as synthetic fabrics differ from linen. It Involves nothing less than introducing new genes into crops, thereby touching the most basic processes of life. No standard program of cross-breeding can add fi sh genes to corn, but such modifi cations would be straightforward in today’s labs.The process by which traits are transmitted from parent to Child has long been a subject for speculation and research. Aristotle suggested that the blood carried hereditary information, a notion that was widely accepted in the West for 2,000 years. By the end of the seventeenth century, following the development of microscopes, Aristotle’s theory had been disproved, as ova and sperm cells were identifi ed in humans and animals. In the 1860s the Austrian monk Gregor Mendel performed the fi rst systematic research on plant generics with his famous studies of garden peas. His work introduced the concept of the gene as a unit of heredity, as when we speak of “a gene for blue eyes.” Still, although scientists spoke of genes as if they actually existed, no one knew what they were made of or how they worked.In 1868 the Garman chemist Friedrich Meischer discovered the substance we now call DNA, but he and his successors did not appreciate that it had anything to do with heredity. Meanwhile, microscopists identifi ed the cell structures called chromosomes, which got their name because they strongly absorbed the dyes that made cell structures visible. By the end of that century, chromosomes had been identifi ed2Reading 33-2with heredity in both plants and animals. However, geneticists believed that they encoded their genetic information in protein molecules, not DNA. They were aware that DNA existed within chromosomes, but it appeared to have too simple a structure to carry the vast amount of information that was needed to pro-duce the enormous diversity of nature. Scientists thought DNA merely provided structural support for the information-carrying proteins.In 1944 Oswald Avery tentatively identifi ed DNA as the true carrier of molecular information. Alfred Hershey confi rmed this in 1952. Now the roles of protein and DNA within a chromosome reversed, with proteins in the structural role. Less than a year later, James Watson and Francis Crick determined DNA’s molecular shape as a double helix.Researchers now declared that a gene is a length of DNA that carries a code for producing a particu-lar type of protein molecule, such as a hormone or enzyme. Many such genes, strung together, make up a chromosome. A revolution in science ensued as researchers solved the genetic code. Crick summarized the fi ndings in 1966. He gave a succinct table that showed how DNA could carry specifi c information, as if with letters of the alphabet, that combined to determine specifi c proteins that a cell would produce.Yet, despite all these advances, scientists could only describe what was going on inside cells; they had no way to intervene directly on a molecular level. The art of gene-splicing, which drew on basic research in molecular biology, dates from 1972. In that year Stanley Cohen and Herbert Boyer introduced a set of techniques that made it possible to cut and splice strands of DNA with much the same facility as when edit-ing a movie in Hollywood. Boyer and Cohen succeeded in adding specifi c new genes to bacteria, something that had never been clone before. Although their methods worked only with microorganisms, the principles behind them applied to plants and animals as well.When Boyer and Cohen added new genes to bacteria and yeast, they introduced
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