42 practice makes perfect Advanced English Reading and Comprehension
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1 Imagine a tomato that doesn’t lose its lavor when it’s refrigerated, a potato that doesn’t
absorb oil when it’s deep-fried, or a peanut that doesn’t cause fatal allergic reactions. And what if
plants and animals could deliver vaccines and pharmaceuticals in addition to vital nutrients? Are
these foods just the product of someone’s wild imagination, or can biotechnology create tastier,
more appealing, and more nutritious foods? And if so, are genetically engineered superfoods all
that they’re cracked up to be?
2 For thousands of years, farmers have been using low-tech forms of genetic manipulation to
modify plants and animals. From experience, farmers understood that plants and animals with
desirable qualities produced ofspring with the same traits. By mating superior animals or collect-
ing seed from the best plants, farmers could improve their livestock and increase crop yields. In
the mid-nineteenth century, Gregor Mendel’s experiments with garden peas transformed tradi-
tional breeding practice into the science of genetics and sowed the seeds of an agricultural
revolution.
3 he irst of many scientists to apply Mendel’s indings to commercial crop development was
Dr. John Garton, who invented the process of multiple cross-fertilization of crop plants in
England. Gartons Agricultural Plant Breeders became the irst plant-breeding business; its irst
commercial product was Abundance Oat, bred from a controlled cross in 1892. Between 1904 and
World War II, Nazareno Strampelli experimented with wheat hybrids in order to signiicantly
reduce Italy’s dependence on grain imports. In 1943, Norman Borlaug, an American agronomist,
humanitarian, and Nobel laureate, conducted agricultural research in Mexico to develop high-
yielding varieties of cereal grains. His eforts led to the “Green Revolution,” which increased world
food production into the 1970s through the distribution of hybridized seeds, the expansion of
irrigation, the modernization of agricultural management, the development of more eicient
farm machinery, and the introduction of synthetic fertilizers and pesticides.
4 At the same time, government institutions, universities, crop science industry associations,
and private companies were competing to come up with hardier, higher-yielding hybrids that
were resistant to disease, pests, and harsh climate conditions. In the 1970s and 1980s, breakthrough
research in molecular biology provided scientists with the necessary tools to alter organisms at
the cellular level. In 1972, scientists discovered the ability of restriction enzymes to identify genes
and cut them out of a chromosome. hat same year, researchers at Stanford University succeeded
in splicing DNA fragments from diferent organisms. hree years later, the discovery of another
group of enzymes, or ligases, made splicing genes easier. Further research into restriction enzymes
revealed that once an inserted gene was accepted by its host organism, it could also be replicated
when cells divided.
5 Genetic engineering, or recombinant DNA technology, was able to achieve with precision
and eiciency what traditional breeding could never have accomplished: the creation of a trans-
genic organism that contained genes from another organism. he irst to make it onto the cover
of a magazine (the December 1982 issue of Nature) was a rat-sized transgenic mouse engineered
with a rat gene for growth. he food industry, of course, had a strong interest in biotechnology,
and the U.S. government gave genetic engineering technology the green light by providing grants
for research into genetic manipulation of food crops. he early 1980s saw a proliferation of bio-
technology companies in the ields of agriculture and pharmaceuticals, where the potential suc-
cesses of recombinant DNA promised to be as lucrative as they were innovative.
6 By the mid-1980s, recombinant DNA technology moved from the laboratory into ields and
markets. In 1986, the irst transgenic tobacco crops were grown in the United States and France,
and by 1997, 10 percent of corn and 14 percent of soybeans in the U.S. were grown from genetically
engineered seeds. he next crops to be modiied were herbicide- and insect-resistant canola, cot-
ton, potatoes, squash, and tomatoes. Chymosin, the irst genetically engineered food to receive, in
1990, Food and Drug Administration (FDA) approval, began to replace rennet in the production