TPO阅读42文本答案翻译

TPO-42Geographic Isolation of Speciesbiologist Ernst mayrdefined a species as an actually or potentially interbreeding population that does not interbreed with other such popullya key event in the origin of many species is the separation of a Population with its gene pool(all of the genes in a Population at any one time)fromwith its gene pool isolated，Separate population是its own evolutilonary course。in the formation of many species，The initial isolation of a population seems to have been a geographic barrier。this mode of evolving new speces is called allo patric specation。many factors can isolate a population geographically。a mountain range may emerge and gradually split a population of organisms that can inhabit only l oul and rakes，certain fish popullations might becomesimilari，a creeping glacier may gradually divide a population，Or a land bridge such as the isth mus of Panama may form and separate the maringToo many words you dont know？Look them up in 新托福TPO阅读词汇速查速记！Wechat: geeqi0805how formidable must a geographic barrier be to keep popullations apart？it depends on the ability of the organisms to move across barriers。birds and coyotes can easily cross mountain and rivers。the passage of wind-blown Tree pollen is also not hindered by such barriers，and the seeds of many plants may be carried back and forth on animals infor example，the grand canyon，in the souththwestern United States，Separate the range of the while-tailed antelope sqirrel fromsmaller，With a shorter tail that is white underneath，The white-tailed antelope sqirrel in habits deserts north of The canyon and west of The canyongeographic isolation creates opportunities for new species to develop，But it does not nec essarily lead to new species because specific occurs small popullations of stray animals and plants from the southamerican mainland that managed to colonize the galapgos islands gave rise to all the speemswhen oceanic islands are far enough apart to permit population to evolve in isolation，but close enough to allow occasional dispersion s to occurthe galapachgos island chain is one of the world s greatest show scases of evolution .each island Was born from under water volcanoes And Was gradually covered by organisms derived from strays that rode the ocean currents And winds fromthe speces on the galapgos islands today，most of which occur nohere else，descended from organisms that floated，flew，Or were blownfor instance，The galapgos island chain has a total of thirten speces of closed related birds called galapgos finches。these birders have many similarities but d If fer in their feeding habits and their beak type，Which is correlated with what they eat。accumulated evidence indicates that all thirten finch speces evolved from a single small population of ances Tral bird that colonized one of the isllonizedcomplely isolated on The islland after migrating from The mainland，The founder population may have undersgone significant changes in its geneA few individuals of this new species may have been blown by storms to A neighboring island。 isolated on this second island，The second founder population could have evolved into a second new species，Which could later re colonizetoday each galapaches island has multiple speces of finches，with as many as ten on some islands1.the word“key”in the passage is closest in meaning toA.earlyB.crucialC.noticeableD.frequent2.the word“initial”in the passage is closest in meaning toA.bestB.usualC.第一次D.实际you enjoy the consenience of having all vocal ability questions listed as a separate part in 新托福TPO阅读词汇速查速记。3.according to paragraph1，allo patric specification is possible whenA.a population contains all the different genes present in a species at a particular timeB.a population becomes isolated due to the presence of a geographic barrierC.genetic mixing begins to occur in previously separate popullations of a speciesD.a species is successful in crossing a geographic barrier4.how is paragraph 2 related to paragraph 1？A.paragraph 2 points out a number of ways in which the phenom on of geographic isolation mentioned in paragraph 1是occurB.paragraph 2 identifies disc veries that led to the conclusion presented in paragraph 1 that geographic isolation has played a role in the origin of manageC.paragraph 2 provides evidence supporting the statement in paragraph 1 that a population can