GRE阅读题目解析:基因研究新方法

2018-01-04 11:15

来源：新东方在线

作者：

　　New methods developed in genetic research have led taxonomists to revise their views on the evolutionary relationships between many species. Traditionally the relatedness of species has been ascertained by a close comparison of their anatomy. The new methods infer the closeness of any two species’ relationship to each other directly from similarities between the species’ genetic codes.

　　3. Which of the following conclusions is best supported by the information?

　　A. The apparent degree of relatedness of some species, as determined by anatomical criteria, is not borne out by their degree of genetic similarity.

　　B. When they know the differences between two species’ genetic codes, taxonomists can infer what the observable anatomical differences between those species must be.

　　C. The degree to which individuals of the same species are anatomically similar is determined more by their genetic codes than by such environmental factors as food supply.

　　D. The traditional anatomical methods by which taxonomists investigated the relatedness of species are incapable of any further refinement.

　　E. Without the use of genetic methods, taxonomists would never be able to obtain any accurate information about species’ degrees of relatedness to one another.

　　1

　　New methods developed in genetic research have led taxonomists to revise their views on the evolutionary relationships between many species.

　　随基因研究的进步发展出的新方法，令生物分类学家重新考虑许多物种间的进化关系。

　　2

　　Traditionally the relatedness of species has been ascertained by a close comparison of their anatomy.

　　确定物种间的相关性的传统方法，是通过彻底地解剖对比。

　　3

　　The new methods infer the closeness of any two species’ relationship to each other directly from similarities between the species’ genetic codes.

　　新方法是直接从物种间基因编码的相似点，推断任何两物种间彼此的亲缘关系。

　　3. Which of the following conclusions is best supported by the information?

　　A. The apparent degree of relatedness of some species, as determined by anatomical criteria, is not borne out by their degree of genetic similarity.

　　B. When they know the differences between two species’ genetic codes, taxonomists can infer what the observable anatomical differences between those species must be.

　　C. The degree to which individuals of the same species are anatomically similar is determined more by their genetic codes than by such environmental factors as food supply.

　　D. The traditional anatomical methods by which taxonomists investigated the relatedness of species are incapable of any further refinement.

　　E. Without the use of genetic methods, taxonomists would never be able to obtain any accurate information about species’ degrees of relatedness to one another.

　　选 A

　　问法比较常规，从文段能够推出哪种合理结论。保持收敛就好。

　　A

　　某些根据解剖标准看，明显有亲缘关系的物种，基因上并不相似。

　　明显正确的选项，甚至让人觉得是废话的选项，如果不是这样，taxonomists 根本就没有必要 revise their views(句 1)。

　　非常 ETS 的选项，看到就该感到温暖，亲切，自己人，面带忠厚。

　　B

　　一旦知道了两物种间基因编码的相似点，分类学家就可以推测它们在解剖上有什么不同。

　　未知信息。文章指说 taxonomists 可以根据基因方法判断亲缘关系，可没说过把这种方法用于判断物种间的解剖相似性。

　　C

　　同一物种的个体，身体构造的相似更多是由基因决定的，而不是环境因素比如食物供给。

　　同物种的个体，本来就该有解剖相似性，而且文章没有讨论过同物种个体。

　　D

　　分类学家赖以研究物种亲缘关系的，传统的解剖学方法，已经不能被优化了。

　　未知信息。现在看来，不是能不能被优化的问题，而是解剖学方法可能根本就是错的，需要重新 revise 的问题。

　　E

　　不用基因方法，分类学家永远无法获得物种亲缘关系的任何准确信息。

　　未知信息。很可能是错的，虽然解剖学方法被淘汰了，但能不能说它每一次都错呢?似乎很难，总该正确地解释过某些问题吧，就像传统医学当然治愈过不计其数的疾病，虽然它需要被现代标准 revise 。

　　讲讲啥叫 ——

　　保持收敛

　　收敛当然是一个数学或经济学中的概念，但我常说的收敛没那么专业，绝大多数指的是不要发散思维。

　　我们在阅读中经常会有两种基本模式。

　　一种是吸收式思维，假定所有读到的信息为真，并尝试组合所有信息，以达成对当前话题的尽量全面的勾画。为了能够把新信息统一地解释在原有框架内，大脑是不惜发散，或者说脑补一定的中间过程的，就好像当我们试图理解一个偷面包的小偷为什么偷，总是最容易想象他可能买不起，或者当时饿极了，甚至是为了其他饥饿的人不惜去偷。

　　另一种是批判式思维，每读到一片新信息，都批判地问自己，从已知信息中能够完全地推导出此信息吗?如果不能，是因为新信息与已知条件及其推论相矛盾?还是因为缺乏必要的限定条件?如果能，是否包含某种未明示的假设 unstated assumptions?

　　当我们阅读文段，总是先采用吸收式思维，尝试在现有框架中拼装新信息，试图把握文段所讨论的问题的全貌，但在题目有要求时(就像本题的要求)，你应该非常熟练地切换为批判式思维。所谓保持收敛，或所谓不要发散，就是提醒你，此刻该切换了，该批判了，不要无条件地假定新信息成立了。

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