2010考研英语历年真题来源报刊阅读:为什么转基因食品对我们有好处?
Why GM is good for us
Farm-raised pigs are dirty, smelly animals that get no respect. They’re also an environmental hazard. Their manure contains phosphorus, which, when it rains, runs off into lakes and estuaries, depleting oxygen, killing fish, stimulating algae overgrowth and emitting greenhouse gases.
Doing away with the pig is not an option. Pigs provide more dietary protein, more cheaply, to more people than any other animal. Northern Europe still maintains the highest pig-to-human ratio in the world (2-1 in Denmark), but East Asia is catching up. During the 1990s, pork production doubled in Vietnam and grew by 70 percent in China—along densely populated coastlines, pig density exceeds 100 animals per square kilometer. The resulting pollution is “threatening fragile coastal marine habitats including mangroves(红树林), coral reefs and sea grasses,” according to a report released in February by the Food and Agriculture Organization of the United Nations.
As it turns out, there is a solution to the pig problem, but it requires a change of mind-set among environmentalists and the public. Two Canadian scientists have created a pig whose manure doesn’t contain very much phosphorus at all. If this variety of pig were adopted widely, it could greatly reduce a major source of pollution. But the Enviropig, as they call it, is the product of genetic modification—which is anathema(忌讳) to many Westerners.
The Enviropig is one of many new technologies that are putting environmentalists and organic-food proponents in a quandary: should they remain categorically(无条件的) opposed to genetically modified (GM) foods even at the expense of the environment? Elsewhere, trees grown for paper could be made amenable to much more efficient processing, reducing both energy usage and toxic chemical bleach in effluents from paper mills. The most significant GM applications will be ones that help alleviate the problem of agriculture, which accounts for 38 percent of the world’s landmass and is crowding out natural ecosystems and species habitats.
In fact, although all commonly used pesticides dissipate so quickly that they pose a miniscule health risk to consumers, allergic food reactions to natural products kill hundreds of children each year. Genetically modified foods could greatly reduce this risk. U.S. Department of Agriculture scientist Eliot Herman has already created a less-allergenic soybean—an important crop for baby foods. Through genetic surgery, Herman turned off the soy gene responsible for 65 percent of allergic reactions. Not only was the modified soy less allergenic in tests but, as Herman explained, “the yield looks perfectly normal, plants develop and grow at a normal rate and they seem to have the same kinds of protein, oil and other good stuff in them.” Other scientists have reported promising results in shutting off allergycausing genes in peanuts and shrimp. Should these advances be turned into products, organic soy or peanut products will be certifiably more dangerous to human health than comparable nonorganic products.
Unfortunately, this won’t happen any time soon. Because no society has ever banned allergenic foods, conventional farmers have no incentive to plant reduced-allergy seeds. And many members of the public have been led to believe that all genetic modifications create health risks. In this climate, much of the needed research isn’t being pursued. Chances are, farmers will continue to grow their polluting organic pork, their allergenic organic soy and their neurotoxinsprayed organic apples. Worse still, they will make sure that no one else gets a choice in the matter of improving the conditions of life on earth—unless, that is, others rise up and demand an alternative.