Gause's Hypothesis托福聽(tīng)力原文翻譯及問(wèn)題答案
2023-05-22 15:46:10 來(lái)源:中國(guó)教育在線
Gause's Hypothesis托福聽(tīng)力原文翻譯及問(wèn)題答案
一、Gause's Hypothesis托福聽(tīng)力原文:
NARRATOR:Listen to part of a lecture in a biology class.
FEMALE PROFESSOR:OK.Back in the 1930's,a biologist named G.F.Gause first proposed what's known as"Gause's hypothesis".
Gause said that whenever you've got two similar species competing for the exact same limited resources,one of them will have some sort of advantage,however slight that'll eventually enable this species to dominate and ultimately exclude the other one,even cause it to become extinct.That's why Gause's hypothesis came to be called"The competitive exclusion principle".Gause did some lab experiments like placing two Paramecium species in the same environment where they would have to compete for the same food.He found that,over time,one species was consistently able to drive out the other,to eliminate it from the habitat,just as his hypothesis predicted.Now,one of the early criticisms of Gause's hypothesis was that,"Sure,it works in simple lab experiments,where you have just two competing species in a controlled environment.But the hypothesis falls apart when applied to natural ecosystems where things are more complex."
Now it's true that in the real world,there are lots of examples that seem to contradict the hypothesis. For example,in the forests of New England,in the northeastern United States,there are some small songbirds called warblers.Yet,these five wobbler species all managed to coexist.—there is no dominance,no exclusion of one species by another....
How is this possible?
Well,turns out that one wobbler species feeds in the uppermost branches,while others favor the middle branches and others feed toward the bottom of the tree.Also,each wobbler species breeds at a different time of year.This way,the period of peak food requirement,when-when the birds are feeding their chicks,varies from one species to the next.
FEMALE PROFESSOR:Yes,Mark.
MALE STUDENT:But does that really contradict Gause's hypothesis?Because,I mean,are those different wobbler species really competing for the same food?I don't think so.I think they're more like,you know,almost cooperating so that they don't have to compete.FEMALE PROFESSOR:Excellent!To the casual observer,the wobblers do seem to contradict Gause's hypothesis since they all live in the same place and eat the same types of insects.
But if you observe these birds more closely,the wobbler species are not really competing with one another for the exact same food at the exact same time.Mark,can you tell us what an ecological niche is?MALE STUDENT:The place where the plant or animal lives,you know,its habitat?FEMALE PROFESSOR:For example?MALE STUDENT:Uh,like the polar bear living in the Arctic,on the ice sheet. The Arctic is its niche,the habitat it's adapted to survive in.
FEMALE PROFESSOR:Okay.That's what most people think of....
But for biologists,the concept of a niche also includes the way an organism functions in its habitat,how it interacts with other plant and animal species,with the soil,the air,the water and so on.Okay,now let's put it all together:
if you have two similar species competing in the same niche,what's going to happen?Susan?FEMALE STUDENT:One will dominate the other and eventually eliminate it.FEMALE PROFESSOR:Okay.
So what could the weaker species do to improve its chances of survival?FEMALE STUDENT:Maybe just move to some other area,you know,away from the competitor?
FEMALE PROFESSOR:That's one possibility.But think of the scientific definition of a niche.Think about the wobblers.
Mark?MALE STUDENT:Maybe it could find some new way of functioning in its habitat so that it wouldn't have to compete with the dominant species.Keep the same habitat but not the exact same niche.FEMALE PROFESSOR:Yes,and there are many ways to do that.—the dominant species feeds in one part of the tree and you feed in another....
MALE STUDENT:If the dominant species needs lots of water,you develop the ability to survive on very little water?FEMALE PROFESSOR:You survive on what's left over.Water,food,nesting or breeding sites,...whatever.
二、Gause's Hypothesis托福聽(tīng)力中文翻譯:
旁白:在生物課上聽(tīng)一部分講座。
女教授:好吧。回到20世紀(jì)30年代,一位名叫G.F.高斯的生物學(xué)家首次提出了所謂的“高斯假說(shuō)”。
高斯說(shuō),每當(dāng)你有兩個(gè)相似的物種競(jìng)爭(zhēng)相同的有限資源時(shí),其中一個(gè)會(huì)有某種優(yōu)勢(shì),無(wú)論多么微小,最終都會(huì)使這個(gè)物種占據(jù)主導(dǎo)地位,最終排斥另一個(gè)物種,甚至導(dǎo)致它滅絕。這就是為什么高斯的假設(shè)被稱為“競(jìng)爭(zhēng)排斥原理”。高斯做了一些實(shí)驗(yàn)室實(shí)驗(yàn),比如把兩種草履蟲(chóng)放在同一個(gè)環(huán)境中,它們必須競(jìng)爭(zhēng)相同的食物。他發(fā)現(xiàn),隨著時(shí)間的推移,一個(gè)物種始終能夠?qū)⒘硪粋€(gè)物種趕出棲息地,將其從棲息地中消除,正如他的假設(shè)所預(yù)測(cè)的那樣?,F(xiàn)在,對(duì)高斯假設(shè)的早期批評(píng)之一是,“當(dāng)然,它在簡(jiǎn)單的實(shí)驗(yàn)室實(shí)驗(yàn)中起作用,在受控環(huán)境中只有兩個(gè)競(jìng)爭(zhēng)物種。但當(dāng)應(yīng)用于自然生態(tài)系統(tǒng)時(shí),該假設(shè)會(huì)分崩離析,因?yàn)槟抢锏那闆r更復(fù)雜?!?/p>
事實(shí)上,在現(xiàn)實(shí)世界中,有很多例子似乎與假設(shè)相矛盾 ;例如,在美國(guó)東北部新英格蘭的森林中,有一些小型鳴鳥(niǎo),叫做鶯。然而,這五種搖擺物種都設(shè)法共存-一個(gè)物種不存在優(yōu)勢(shì),也不存在另一個(gè)物種排斥。。。。
這怎么可能?
事實(shí)證明,一種搖擺的物種在最上面的樹(shù)枝上覓食,而其他物種則喜歡中間的樹(shù)枝,其他物種則向樹(shù)的底部覓食。此外,每種搖擺動(dòng)物在一年中的不同時(shí)間繁殖。這樣,鳥(niǎo)類喂食小雞時(shí)的食物需求高峰期因物種而異;
女教授:是的,馬克。
男學(xué)生:但這真的與高斯的假設(shè)相矛盾嗎?因?yàn)?,我的意思是,這些不同的搖擺動(dòng)物物種真的在爭(zhēng)奪相同的食物嗎?我不這么認(rèn)為。我認(rèn)為他們更像是,你知道,幾乎是合作,這樣他們就不必競(jìng)爭(zhēng)了。女教授:太好了!對(duì)于不經(jīng)意的觀察者來(lái)說(shuō),搖擺者似乎與高斯的假設(shè)相矛盾,因?yàn)樗麄兌忌钤谕粋€(gè)地方,吃同樣類型的昆蟲(chóng)。
但如果你更仔細(xì)地觀察這些鳥(niǎo)類,搖擺鳥(niǎo)物種并不是在同一時(shí)間為了同樣的食物而相互競(jìng)爭(zhēng)。馬克,你能告訴我們什么是生態(tài)位嗎?男學(xué)生:植物或動(dòng)物生活的地方,你知道,它的棲息地?女教授:比如說(shuō)?男學(xué)生:嗯,就像生活在北極的北極熊,在冰原上 ;北極是它的生態(tài)位,是它適應(yīng)生存的棲息地。
女教授:好的。這就是大多數(shù)人的想法。。。。
但對(duì)于生物學(xué)家來(lái)說(shuō),生態(tài)位的概念還包括生物體在其棲息地中的功能,以及它如何與其他植物和動(dòng)物物種、土壤、空氣、水等相互作用。好吧,現(xiàn)在讓我們把它們放在一起:
如果你有兩個(gè)相似的物種在同一生態(tài)位競(jìng)爭(zhēng),會(huì)發(fā)生什么?蘇珊?女學(xué)生:一個(gè)會(huì)支配另一個(gè),最終消除它。女教授:好的。
那么,弱小的物種可以做些什么來(lái)提高它們的生存機(jī)會(huì)呢?女學(xué)生:也許就搬到別的地方,你知道,遠(yuǎn)離競(jìng)爭(zhēng)對(duì)手?
女教授:這是一種可能性。但是想想生態(tài)位的科學(xué)定義。想想搖擺器。
做記號(hào)男學(xué)生:也許它可以在棲息地找到一些新的運(yùn)作方式,這樣它就不必與優(yōu)勢(shì)物種競(jìng)爭(zhēng)了。保持相同的棲息地,但不是完全相同的生態(tài)位。女教授:是的,有很多方法-優(yōu)勢(shì)物種在樹(shù)的一部分進(jìn)食,而你在另一部分進(jìn)食。。。。
男學(xué)生:如果占優(yōu)勢(shì)的物種需要大量的水,你會(huì)在很少的水里發(fā)展生存的能力嗎?女教授:你靠剩下的東西生存。水、食物、筑巢或繁殖地點(diǎn)等等。
三、Gause's Hypothesis托福聽(tīng)力問(wèn)題:
Q1:1.What is the main purpose of the lecture?
A.To explain why a species of warbler might become extinct
B.To discuss the evidence that led Gause to formulate his hypothesis
C.To examine a hypothesis about what happens when species compete
D.To identify factors that allow some species to dominate others
Q2:2.According to Gause's hypothesis,what happens when two similar species compete for limited resources in the same habitat?
A.Both species will develop new nutritional requirements.
B.Both species will change their behaviors.
C.One of the species will eliminate the other from the habitat.
D.One of the species will spread into a new habitat.
Q3:3.How do the five species of warbler described by the professor manage to coexist?Click on 2 answers
A.By using different materials to build their nests
B.By feeding in different sections of the tree
C.By eating different kinds of insects
D.By breeding at different times of the year
Q4:4.What is the professor's opinion about Gause's hypothesis?
A.She thinks that it has not been disproved.
B.She thinks it is contradicted by basic laboratory experiments.
C.She thinks that it cannot be adequately investigated.
D.She believes that it is contradicted by the competitive exclusion principle.
Q5:5.What does the professor imply about the relationship between an organism's niche and its habitat?
A.An organism's niche is exactly the same as its habitat.
B.An organism's niche is only partly defined by its habitat.
C.An organism's habitat is almost always more complex than its niche.
D.An organism can change its habitat but cannot change its niche.
Q6:6.Why does the professor says this:
A.To encourage other students to participate in the discussion.
B.To correct an error in the student's statement.
C.To encourage the student to answer more specifically.
D.To confirm that the student's answer is correct.
四、Gause's Hypothesis托福聽(tīng)力答案:
A1:正確答案:C
A2:正確答案:C
A3:正確答案:BC
A4:正確答案:A
A5:正確答案:B
A6:正確答案:D
>> 雅思 托福 免費(fèi)測(cè)試、量身規(guī)劃、讓英語(yǔ)學(xué)習(xí)不再困難<<