" There are no shortcuts in evolution," famed Supreme Court justice Louis Brandeis once said. He might have reconsidered those w

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问题     " There are no shortcuts in evolution," famed Supreme Court justice Louis Brandeis once said. He might have reconsidered those words if he could have foreseen the coming revolution in biotechnology, including the ability to alter genes and manipulate stem cells. These breakthroughs could bring on an age of directed reproduction and evolution in which humans will bypass the incremental process of natural selection and set off on a high-speed genetic course of their own. Some of the latest and greatest advances like pluripotent stem cells, gene targeting, and artificial chromosomes could leapfrog over evolution and let us take control of our genome, maybe even turn ourselves into a whole new species.
    Bioethicist John Harris of the University of Manchester, believes that achieving our potential "might require some deliberate changes" to our genes. He predicts that genetic engineering will eventually lead to what he calls "enhancement evolution. " Through the nuanced use of biotechnology, enhancement evolution will gradually introduce genes that improve the species, one person at a time. At that point, deliberate selection will replace natural selection as the driving force for species change. " We are not suited to survive designed as we are," Harris says. " We are hugely vulnerable to diseases, and new diseases come along all the time. It’s amazing we haven’t been entirely wiped out by one. "
    The first changes to the human genome, Harris believes, will happen within small test populations. This will allow us to assess the risks and benefits of the modifications and then decide how to proceed.
    Enhancement evolution has plenty of critics. Lanza, for one, is uneasy about giving parents the power to design their children’s genomes. What if a couple wants a world-class athlete in the family and provides those genes, but the child grows up wanting to play chess, he asks. And what if some of the modifications go seriously wrong? Who should have the final say on when and how the human genome should be changed?
    On the other hand, if technology can enable us to eliminate disease and disabilities from our children or insert genes that might make them smarter or better looking, why wouldn’t we use it? As DNA guru James Watson once said, " Evolution can be just damn cruel. " At least it is today. Tomorrow the responsibility for evolution may rest on our own shoulders—for better or for worse.  
Which of the following can be the advantage of enhancement evolution?

选项 A、Bringing in delicate changes to genes.
B、Replacing natural selection.
C、Changing human species entirely.
D、Enhancing human immunity.

答案D

解析 推断题。解答本题需正确理解Harris的观点,定位至第二段。Harris在介绍完“增强性进化”的概念之后,特别提出We are hugely vulnerable to diseases…It’s amazing we haven’t been entirely wiped out byone,说明在他看来,人类基因的弱点在于抗病性差,而通过人为干预进化,改写基因组,便可改善这种状况,这无疑存在很大的裨益。因此,本题答案为[D]。三个错项可首先排除[B],它曲解了原文所说的replacenatural selection as the driving force,原文并不是说能完全取代自然选择,因此错误。[A]和[C]似乎在原文能找到依据:[A]项源自第二段第一句“…require some deliberate changes”to our genes。[C]项源自第一段末尾turn ourselves into a whole new species,但[A]仅是增强性进化的手段,不能说是裨益;而[C]所述的变化也未必是对人类有利的。
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