2014考研英語(yǔ)復(fù)習(xí)：模擬試題之閱讀理解練習(xí)(六十五)_跨考網(wǎng)

　　2014考研英語(yǔ)復(fù)習(xí)：模擬試題之閱讀理解練習(xí)(六十五)

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　　What will it mean to know the complete human genome. Eric Lander of MIT's Whitehead Institute compares it to the discovery of the periodic table of the elements in the late 1800s. "Genomics is now providing biology's periodic table." says Lander. "Scientists will know that every phenomenon must be explainable in terms of this meansly list" which will in on a single CD-ROM. Already researchers are extracting DNA from patients, attaching fluorescent molecules and sprinkling the sample on a glass chip whose surface is speckled with 10,000 known genes. A laser reads the fluorescence, which indicates which of the known genes on the chip are in the mystery sample from the patient. In only the last few months such "gene-expression monitoring" has diagnosed a muscle tumor in a boy thought to have leukemia, and distinguished between two kinds of cancer that require very different chemotherapy.

　　But decoding the book of life poses daunting moral dilemmas. With knowledge of our genetic code will come the power to re-engineer the human species. Biologists will be able to use the genome as a parts list much as customers scour a list of china to replace broken plates and may well let prospective parents choose their unborn child's traits. Scientists have solid leads on genes for different temperaments, body builds, statures and cognitive abilities. And if anyone still believes that parents will recoil at praying God, and leave their baby's fate in the hands of nature recall that couples have already created a frenzied market in eggs from Ivy League women.

　　Beyond the profound ethical issues are practical concerns. The easier it is to change ourselves and our children, the less society may tolerate those who do not; warns Lori Andrews of Kent College of Law. If genetic tests in uterus predict mental dullness, obesity, short stature or other undesirable traits of the moment will society disparage children whose parents let them be born with those traits? Already, Andrews finds, some nurses and doctors blame parents for bringing into the world a child whose birth defect was diagnosable before delivery; how long will it be before the same condemnation applies to cosmetic imperfections? An even greater concern is that well-intentioned choices by millions of individual parents-to-be could add up to unforeseen consequences for all of humankind. It just so happens that some disease genes also confer resistance to disease: carrying a gene for sickle cell anemia, for instance, brings resistance to malaria. Are we smart enough, and wise enough, to know how knocking out "bad" genes will affect our evolution as a species?