托福閱讀TPO30(試題 答案 譯文)

托福閱讀原文

【1】A heated debate has enlivened recent studies of evolution. Darwin's original thesis, andthe viewpoint supported by evolutionary gradualists, is that species change continuously butslowly and in small increments. Such changes are all but invisible over the short time scale ofmodern observations, and, it is argued, they are usually obscured by innumerable gaps in theimperfect fossil record. Gradualism, with its stress on the slow pace of change, is a comfortingposition, repeated over and over again in generations of textbooks. By the early twentiethcentury, the question about the rate of evolution had been answered in favor of gradualism tomost biologists' satisfaction.

【2】Sometimes a closed question must be reopened as new evidence or new argumentsbased on old evidence come to light. In 1972 paleontologist Stephen Jay Gould and NilesEldredge challenged conventional wisdom with an opposing viewpoint, the punctuatedequilibrium hypothesis, which posits that species give rise to new species in relativelysudden bursts, without a lengthy transition period. These episodes of rapid evolution areseparated by relatively long static spans during which a species may hardly change at all.

【3】The punctuated equilibrium hypothesis attempts to explain a curious feature of thefossil record—one that has been familiar to paleontologist for more than a century but hasusually been ignored. Many species appear to remain unchanged in the fossil record for millionsof years—a situation that seems to be at odds with Darwin's model of continuous change.Intermediated fossil forms, predicted by gradualism, are typically lacking. In most localities agiven species of clam or coral persists essentially unchanged throughout a thick formation ofrock, only to be replaced suddenly by a new and different species.

【4】The evolution of North American horse, which was once presented as a classic textbookexample of gradual evolution, is now providing equally compelling evidence for punctuatedequilibrium. A convincing 50-million-year sequence of modern horse ancestors—eachslightly larger, with more complex teeth, a longer face, and a more prominent central toe—seemed to provide strong support for Darwin's contention that species evolve gradually.But close examination of those fossil deposits now reveals a somewhat different story. Horsesevolved in discrete steps, each of which persisted almost unchanged for millions of years andwas eventually replaced by a distinctive newer model. The four-toed Eohippus preceded thethree-toed Miohippus, for example, but North American fossil evidence suggests a jerky,uneven transition between the two. If evolution had been a continuous, gradual process,one might expect that almost every fossil specimen would be slightly different from every year.

【5】If it seems difficult to conceive how major changes could occur rapidly, consider this: analteration of a single gene in files is enough to turn a normal fly with a single pair of wings intoone that has two pairs of wings.

【6】The question about the rate of evolution must now be turned around: does evolutionever proceed gradually, or does it always occur in short bursts? Detailed field studies of thickrock formations containing fossils provide the best potential tests of the competing theories.

【7】Occasionally, a sequence of fossil-rich layers of rock permits a comprehensive look atone type of organism over a long period of time. For example, Peter Sheldon's studies oftrilobites, a now extinct marine animal with a segmented body, offer a detailed glimpse intothree million years of evolution in one marine environment. In that study, each of eightdifferent trilobite species was observed to undergo a gradual change in the number ofsegments—typically an increase of one or two segments over the whole time interval. Nosignificant discontinuous were observed, leading Sheldon to conclude that environmentalconditions were quite stable during the period he examined.

【8】Similar exhaustive studies are required for many different kinds of organisms from manydifferent periods. Most researchers expect to find that both modes of transition from onespecies to another are at work in evolution. Slow, continuous change may be the normduring periods of environmental stability, while rapid evolution of new species occurs duringperiods of environment stress. But a lot more studies like Sheldon's are needed before we cansay for sure.

托福閱讀試題

1.The word "innumerable" in the passage is closest in the meaning to

A.countless.

B.occasional.

C.large.

D.repeated.

2.According to paragraph 1, all of the following are true EXCEPT

A.Darwin saw evolutionary change as happening slowly and gradually.

B.Gaps in the fossil record were used to explain why it is difficult to see continuous smallchanges in the evolution of species.

C.Darwin's evolutionary thesis was rejected because small changes could not be observed inthe evolutionary record.

D.By the early twentieth century, most biologists believed that gradualism explainedevolutionary change.

3.Which of the sentences below best expresses the essential information in thehighlighted sentence in the passage paragraph 2 ? Incorrect choices change themeaning in important ways or leave out essential information.

A.The punctuated equilibrium hypothesis challenged gradualism, which holds that speciesevolve in relatively sudden bursts of brief duration.

B.The punctuated equilibrium hypothesis developed by Stephen Jay Gould and Niles Eldredgewas challenged in 1972.C.In 1972 Stephen Jay Gould and Niles Eldredge challenged gradualismby positing that change from one species to another cannot occur without a lengthytransition period.

D.The punctuate equilibrium hypothesis, in opposition to gradualism, holds that transitionsfrom one species to another occur in comparatively sudden burst.

4.According to paragraph 1 and paragraph 2, the punctuated equilibrium hypothesisand the gradualism hypothesis differed about

A.Whether the fossil record is complete.

B.Whether all species undergo change.

C.Whether evolution proceeds an a constant rate.

D.How many new species occur over long periods of time.

5.According to paragraph 3, the lack of intermediate fossils in the fossil record of somespecies

A.has been extensively studied by paleontologist for over a century.

B.contradicts the idea that most species have remained unchanged for millions of years.

C.challenges the view that evolutionary change is gradual.

D.is most common in the fossil records of clam and coral species.

6.The word "compelling" in the passage paragraph 4 is closest in the meaning to

A.surprising.

B.persuasive.

C.controversial.

D.detailed.

7.Paragraph 4 mentions that North American horses have changed in all the followingways EXCEPT in

A.the number of toes they have.

B.the length of their face.

C.their overall size.

D.the number of years they live.

8.The word "alteration" in the passage paragraph 5 is closest in meaning to

A.imperfection.

B.replacement.

C.change.

D.duplication.

9.According to paragraph 7, Peter Sheldon's studies demonstrated which ofthefollowing about trilobites?

A.They underwent gradual change over a long time period.

B.They experienced a number of discontinuous transitions during their history.

C.They remained unchanged during a long period of environmental stability.

D.They evolved in ways that cannot be counted for by either of the two competing theories.

10.The word "occasionally" in the passage paragraph 7 is closest in meaning to

A.undoubtedly.

B.basically.

C.once in a while.

D.to some extent.

11.The main purpose of paragraph 7 is to

A.Describe one test of the competing theories.

B.Provide an example of punctuated equilibrium.

C.Describe how segmented animals evidence both competing theories.

D.Explain why trilobites became extinct.

12. Look at the four squares [■] that indicate where the following sentence can beadded to the passage.Where could the sentence best fit? They believe thatenvironmental conditions may play a crucial role in determining which of the twomodes will be in operation over a given period.

■【A】Similar exhaustive studies are required for many different kinds of organisms from manydifferent periods. ■【B】Most researchers expect to find that both modes of transition fromone species to another are at work in evolution.■【C】Slow, continuous change may be thenorm during periods of environmental stability, while rapid evolution of new species occursduring periods of environment stress. ■【D】But a lot more studies like Sheldon's are neededbefore we can say for sure.

13.Directions: selected from the seven phrases below the phrases that correctlycharacterize punctuated equilibrium and the phrases that correctly characterizegradualism. Two of the phrases will not be used. This question is worth 3 points.

A.States that new species emerge from existing species during relatively brief period of time.

B.Was first formulated by Charles Darwin.

C.Explain why North American horses have become smaller over time.

D.States that new species evolve slowly and continuously from existing species.

E.Explain the lack of intermediate fossil forms in the fossil record of many species.

F.Competition is usually strongest when the density of the competing populations is the same.

G.States that a species will not change unless its environment changes.

1 )

Gradualism

A B C D E F G

2 )

punctuated equilibrium

A B C D E F G

托福閱讀答案

1.innumerable是不可計數(shù)的，A是無數(shù)的，B是偶然的，C是大的，D是重復的。這個單詞是numerable加否定前綴，很容易就能推出意思來。

2.A答案對應第一段第二句， B對應第一段第三句，D對應一段最后一句。C與原文沖突，原文一直在說darwin理論被人們廣泛接受。

3.高亮句子的主干部分是斷點平衡論挑戰(zhàn)了原來的漸進論，然后解釋了斷點平衡論的內(nèi)容。A選項which修飾不明，容易產(chǎn)生誤解;B選項與原文矛盾，C與原文不符，原文S和N的觀點是change的發(fā)生是withoutlengthy transition的。D和原文意思相符，并且也包含了所有的主干部分。

4.根據(jù)原文，漸進論是說物種演變是通過長時間的緩慢改變發(fā)生的;斷點平衡論是說物種演變是短期爆發(fā)的。所以選擇C，進化是否是勻速發(fā)生的。

5.根據(jù)lack of intermediate fossils定位到第三段倒數(shù)第二句，在往前看一句說，這一情況對于達爾文學說是不和的，而達爾文學說正是漸進論，這一段的最后也說原來的物種突然被替換，而不是漸漸進化改變的。所以C符合原文意思。 A與原文第一句破折號后矛盾，原文說這一現(xiàn)象一直被Ignored，B選項原文矛盾，該現(xiàn)象應該是反對了達爾文學說，支持了物種有長期不改變的論點。D雖然正確但是只是本段的細節(jié)，不能表達主題，所以不選。

6.Compel本身是強迫，此處作為evidence的形容詞可以延伸為說服力強的。因此答案選B 有說服力的。A是驚奇的，C是有爭議的，D是細節(jié)的。都不沾邊。另外通過句義可以判斷，前文說馬的進化was once 是經(jīng)典的漸進論的證明，is now(輕微轉折)提了"equally"怎么樣的證據(jù)證明了點斷平衡論，前文既然說對gradualevolution很支持，那么后文出現(xiàn)equally，那應該對點斷論也是有力證據(jù)。因此選B。

7.對應部分在第四段的第二句和第五句，只有D選項沒有出現(xiàn)。

8.這一句話說一個怎么樣的單一基因就足以變一個普通飛禽的一對的正常翅為兩對翅膀，所以有推理應該是要改變這個基因。所以選C，Alteration是修改，變更，A選項是不完美，B是替換，D是復制 帶入后都改變了原文的意思。

9.根據(jù)Peter Sheldon定位到原文第二句。后面對trilobites進行了描述，A選項對應了原文第三句，后文又繼續(xù)說沒有明顯的斷點。所以A正確。 B與原文第四句沖突。C與第三句沖突，D原文沒有這種說法。而且上文也表明它符合gradual evolvement。

10.occasionally，是偶然偶爾的意思。A是毫無疑問的，B是基本上，C是偶爾有一次。D是在一定程度上。因此應該選C。并且上文提出問題說是否有過逐漸進化?那么下文給的是一個逐漸進化的例子，所以應該是在表達偶爾有一兩個的意思。

11.上文說實地勘測會給competing theories提供test，第七段就給了試驗例子，那么就證明是A正確。B與原文沖突，這個例子是支持漸進論的。C也不對，理由同上。D與原文目的不符。

12.首先句子開頭出現(xiàn)了They，那么我們應該能在前文找到一個提到人物的地方，句子又提出environmentalcondition的作用，那么后文應該會出現(xiàn)對這一理論的解釋，那么C是符合的，也可以進行代入驗證。

13.A斷點平衡論論點為物種變化發(fā)生突然，快速，符合。B對應文章第一段第一句話，符合漸進論。C與原文第四段第二句矛盾，原文說馬進化會變大。不選。D原文第一段第一句，符合漸進論。E對應原文第三段。符合點斷平衡論。F原文沒提到，不選。G原文最后一段，說漸進論應該會是環(huán)境比較穩(wěn)定的情況下的進化規(guī)則。符合漸進論。

托福閱讀譯文

【1】最近的一個關于進化的研究引發(fā)了激烈的爭論。達爾文的原始論點和進化漸進主義者支持的觀點是物種會持續(xù)地改變，但非常緩慢，增量也很小。這種改變是普遍的，但是現(xiàn)在短時間的觀察是不能察覺的，并且，這個觀點聲稱，它們通常被掩蓋于不完美的化石記錄的不可計數(shù)的缺失中。漸進主義及其對物種緩慢變化的引力讓人欣然接受，并在世代的教科書中重復出現(xiàn)。在20世紀早前之前，令大部分的生物學家滿足于利用漸進主義來回答關于進化速率的問題。

【2】有時，已經(jīng)有了結論的問題必須由在已有證據(jù)基礎上出現(xiàn)的新的證據(jù)和新的論點使其重新展開討論。在1972年，古生物學者Stephen Jay Gould和 Niles Eldredge用相反的論點挑戰(zhàn)了世俗的結論，即斷點平衡說，它假設了物種演變?yōu)樾碌奈锓N是通過相對突然的爆發(fā)，并非通過長時間的過渡時期。迅速的進化期被時間相對更長的靜態(tài)期分開，而在靜態(tài)時期，物種是幾乎完全不變的。

【3】斷點平衡論試著去解釋化石記錄的一個古怪的特點----在超過一個世紀的時間里它已經(jīng)為古生物學者所熟悉，但一直被忽視。許多物種似乎在上百萬年的化石記錄中一直沒有改變，這個情況與達爾文的模型所支持的物種的持續(xù)變化相悖。進化漸進論的支持者所預測的中間狀態(tài)的化石一直沒有出現(xiàn)。在大部分蛤和珊瑚的聚集地，其化石在很厚的巖石中都實際上沒有變化，只是突然被另一新的并且不同的物種而取代。

【4】北美馬的進化曾經(jīng)被用作經(jīng)典的教科書案例來證明漸變進化論，現(xiàn)在卻為斷點平衡學提供了同樣有說服力的證據(jù)。一個有說服力的5千萬年的馬祖先的進化模型----每一代都稍稍大一點，有更復雜的牙齒，更長的臉，和中間更突出的腳趾----這一切都看似強有力的支持了達爾文的論點，物種是逐步地進化的。但是，對這些化石更嚴謹?shù)尿炞C現(xiàn)在揭示了一個不太一樣的故事。馬是在不連續(xù)的步驟中進化的，其中每個進化步驟中間都有上百萬年時間保持不變，在最后被一個不同的更新的模型取代。比如四只腳趾的Eohippus 在三只腳趾的moihippus之前，但北美化石證據(jù)表明在這之間有一個不平穩(wěn)的，不均衡的轉換過程。如果進化一直都是連續(xù)，漸進的過程，人們應該預期到的是每年的化石樣本都會存在細微的差別。

【5】如果很難設想大的改變會迅速發(fā)生，想想這些：一個單一基因的改變就足以將有一對翅膀的蒼蠅變成兩對翅膀。

【6】關于進化速度的問題現(xiàn)在發(fā)生了轉變：進化過程是逐漸發(fā)生的么，還是總是突然短時間的爆發(fā)?對含有化石的厚巖層的細致的現(xiàn)場調(diào)查可以檢驗這兩個備受爭論的理論。

【7】偶爾，有一個系列的化石豐富的巖石可以允許人們綜合性的觀察一種生物在很長一段時間中的變化。比如，Peter Sheldon對于三葉蟲，一種已滅絕的身體分節(jié)的海洋生物，的研究提供了其對三百萬年來在同一海洋環(huán)境下進化的一些細節(jié)。研究中，八種三葉蟲都觀察到了其身體節(jié)數(shù)數(shù)量逐漸改變的過程，在整個時間段中，一般身體都增加了一到兩節(jié)。沒有明顯的不連貫，這使sheldon得出結論：海洋環(huán)境在那段時間是比較穩(wěn)定的。

【8】很多來自不同時期的不同的生物都需要開展相似的相近研究。大多數(shù)研究者希望發(fā)現(xiàn)物種進化的這兩種模式都存在。緩慢的，連續(xù)的變化可能是在環(huán)境穩(wěn)定的時間段下的規(guī)律，而快速進化的新物種則發(fā)生在環(huán)境變化時期的壓力下。但是，我們需要更多的想Sheldon所做的研究以證明這個觀點。
 重點閱讀：  

新東方托福：

新東方托福培訓視頻：

托福輔導：