GRE阅读练习：达尔文理论溯源美国殖民地历史.docxVIP

Word文档下载后（可任意编辑） 第 第 PAGE 1 页 共 NUMPAGES 1 页 GRE阅读练习：达尔文理论溯源美国殖民地历史 GRE阅读训练：GRE阅读练习：达尔文理论溯源美国殖民地历史 GRE考试精品课程指导  Thefirst migrants to the new world had to wait 8000 years to be admitted.  新大陆的第 一批移民在8000年后才被公认。  HOWAmerica was originally colonised is a topic of perennial interest at the AAAS.Until recently, the earliest uncontested archaeological evidence of peopleliving in the New World came from Swan Point, in Alaska. This dates back 14,400years. Linguists, however, maintain that the diversity of native languages inthe Americas could not have arisen so quickly. Conventional models oflinguistic evolution assume tongues separate in the way populations oforganisms do—so that the flow of vowels, words and grammatical structuresbetween groups must cease before new languages can emerge, just as a cessationof gene flow gives rise to new species. This suggests it would take at least50,000 years for a single population speaking a single language to diversifyand spread through the Americas in a way that yielded the pattern heard today.Since Native Americans’ genes do, indeed, indicate they all derive from asingle population, this discrepancy in timing is a paradox.  美国最初如何沦为殖民地一直是美国科学促进会(AAAS)非常感兴趣的话题。最近，我们从阿拉斯加天鹅点得到了一些当时居住在新大陆的部落的考古信息，这些信息是无可争议的。可追溯到14400年前，不过，语言学家认为，美洲本地语言的多样性不可能如此迅速的形成。语言进化的传统模式认为，语言以生物种群的方式分开，因此在新语言出现之前，种群之间的元音，词语和语法结构就不再相互的流动，正如基因流动的停止会形成新的物种一样。这表明，说着单一语言的单一民族，要想语言达到多样化并且通过美洲传播达到今天所听到的模式，至少需要5万年。由于美洲印第安人的基因表明它们都来自同一群体，因此这种时间上的差异是一个矛盾。  Thatparadox may be close to resolution. Recent digs have pushed the physicalevidence of America’s settlement back in time. Meanwhile, as the meeting heardfrom Mark Sicoli, a linguist at the University of Virginia, in Charlottesville,a different model of linguistic evolution brings the common ancestor ofNative-American tongues forward. Apply a few error bars to the results and thetwo estimates touch—at about 25,000 years ago.  这种矛盾可能即将解决。最近的挖掘发现了美国定居点的实物证据。同时，正如Charlottesville的弗吉尼亚大学的语