剑桥雅思15Test2阅读Passage2原文及翻译

每年年中左右，国内“雅思图”都要翘首期盼一件重要大事的来临:雅思真题的发布。无论是备考初期、后期,甚至已经考过雅思的学生，也无论是学生还是老师,都会密切关注新题的发布。今年6月初,《剑15》如约而至、作为国内雅思培训的领军机构，新航道也时间为考生们带来了这太《剑桥雅思真题全解15:学术类》(以下简称《剑15全解》)。

本次我们盛情邀请了新航道全国冬分校最的学科带头人来组织编写这本《剑15全解》。其中，对于以客观选择题为主的听力与阅读部分，仍然请各校团队进行解题思路方面的指导;对于以主观题为主的写作与口语部分，我们则邀请了官方认证考官撰写地道的高分范文，作为官方范文之外的补充。下文中详细整理了剑桥雅思15Test2阅读Passage2原文及翻译，一起来看一下吧！

剑桥15电子版本，请扫描二维码，暗号“优化+剑桥15全解”，会有老师联系并发送资料。

1剑桥雅思15Test2阅读Passage2原文

You should spend about 20 minutes on Questions 14-26, which are based on Reading Passage 2 below.

Should we try to bring extinct species back to life?

AThe passenger pigeon was a legendary species. Flying in vast numbers across North America, with potentially many millions within a single flock, their migration was once one of nature's great spectacles. Sadly, the passenger pigeon's existence came to an end on 1 September 1914, when the last living specimen died at Cincinnati Zoo. Geneticist Ben Novak is lead researcher on an ambitious project which now aims to bring the bird back to life through a process known as 'de-extinction'. The basic premise involves using cloning technology to turn the DNA of extinct animals into a fertilised embryo, which is carried by the nearest relative still in existence - in this case, the abundant band-tailed pigeon - before being born as a living, breathing animal. Passenger pigeons are one of the pioneering species in this field, but they are far from the only ones on which this cutting-edge technology is being trialled.

BIn Australia, the thylacine, more commonly known as the Tasmanian tiger, is another extinct creature which genetic scientists are striving to bring back to life. 'There is no carnivore now in Tasmania that fills the niche which thylacines once occupied,' explains Michael Archer of the University of New South Wales. He points out that in the decades since the thylacine went extinct, there has been a spread in a 'dangerously debilitating' facial tumour syndrome which threatens the existence of the Tasmanian devils, the island's other notorious resident. Thylacines would have prevented this spread because they would have killed significant numbers of Tasmanian devils. 'If that contagious cancer had popped up previously, it would have burned out in whatever region it started. The return of thylacines to Tasmania could help to ensure that devils are never again subjected to risks of this kind.'

CIf extinct species can be brought back to life, can humanity begin to correct the damage it has caused to the natural world over the past few millennia? 'The idea of de-extinction is that we can reverse this process, bringing species that no longer exist back to life,' says Beth Shapiro of University of California Santa Cruz's Genomics Institute. 'I don't think that we can do this. There is no way to bring back something that is 100 per cent identical to a species that went extinct a long time ago.' A more practical approach for long-extinct species is to take the DNA of existing species as a template, ready for the insertion of strands of extinct animal DNA to create something new; a hybrid, based on the living species, but which looks and/or acts like the animal which died out.

DThis complicated process and questionable outcome begs the question: what is the actual point of this technology? 'For us, the goal has always been replacing the extinct species with a suitable replacement,' explains Novak. 'When it comes to breeding, band-tailed pigeons scatter and make maybe one or two nests per hectare, whereas passenger pigeons were very social and would make 10,000 or more nests in one hectare.' Since the disappearance of this key species, ecosystems in the eastern US have suffered, as the lack of disturbance caused by thousands of passenger pigeons wrecking trees and branches means there has been minimal need for regrowth. This has left forests stagnant and therefore unwelcoming to the plants and animals which evolved to help regenerate the forest after a disturbance. According to Novak, a hybridised band-tailed pigeon, with the added nesting habits of a passenger pigeon, could, in theory, re-establish that forest disturbance, thereby creating a habitat necessary for a great many other native species to thrive.

EAnother popular candidate for this technology is the woolly mammoth. George Church, professor at Harvard Medical School and leader of the Woolly Mammoth Revival Project, has been focusing on cold resistance, the main way in which the extinct woolly mammoth and its nearest living relative, the Asian elephant, differ. By pinpointing which genetic traits made it possible for mammoths to survive the icy climate of the tundra, the project's goal is to return mammoths, or a mammoth-like species, to the area. 'My highest priority would be preserving the endangered Asian elephant,' says Church, 'expanding their range to the huge ecosystem of the tundra. Necessary adaptations would include smaller ears, thicker hair, and extra insulating fat, all for the purpose of reducing heat loss in the tundra, and all traits found in the now extinct woolly mammoth.' This repopulation of the tundra and boreal forests of Eurasia and North America with large mammals could also be a useful factor in reducing carbon emissions - elephants punch holes through snow and knock down trees, which encourages grass growth. This grass growth would reduce temperatures, and mitigate emissions from melting permafrost.

FWhile the prospect of bringing extinct animals back to life might capture imaginations, it is, of course, far easier to try to save an existing species which is merely threatened with extinction. 'Many of the technologies that people have in mind when they think about de-extinction can be used as a form of "genetic rescue",' explains Shapiro. She prefers to focus the debate on how this emerging technology could be used to fully understand why various species went extinct in the first place, and therefore how we could use it to make genetic modifications which could prevent mass extinctions in the future. 'I would also say there's an incredible moral hazard to not do anything at all; she continues. "We know that what we are doing today is not enough, and we have to be willing to take some calculated and measured risks.'

Questions 14-17

Reading Passage 2 has six paragraphs, A-F.

Which paragraph contains the following information?

Write the correct letter, A-F, in boxes 14-17 on your answer sheet.

NB You may use any letter more than once.

14 a reference to how further disappearance of multiple species could be avoided

15 explanation of a way of reproducing an extinct animal using the DNA of only that species

16 reference to a habitat which has suffered following the extinction of a species

17 mention of the exact point at which a particular species became extinct

Questions 18-22

Complete the summary below.

Choose NO MORE THAN TWO WORDS from the passage for each answer.

Write your answers in boxes 18-22 on your answer sheet.

The woolly mammoth revival project

Professor George Church and his team are trying to identify the

18………….. which enabled mammoths to live in the tundra. The findings could help preserve the mammoth's close relative, the endangered Asian elephant.

According to Church, introducing Asian elephants to the tundra would involve certain physical adaptations to minimise 19………….. .To survive in the tundra, the species would need to have the mammoth-like features of thicker hair, 20………….. of a reduced size and more 21………….. .

Repopulating the tundra with mammoths or Asian elephant/mammoth hybrids would also have an impact on the environment, which could help to reduce temperatures and decrease 22………….. .

Questions 23-26

Look at the following statements (Questions 23-26) and the list of people below.

Match each statement with the correct person, A, B or C.

Write the correct letter, A, B or C, in boxes 23-26 on your answer sheet.

23 Reintroducing an extinct species to its original habitat could improve the health of a particular species living there.

24 It is important to concentrate on the causes of an animal's extinction.

25 A species brought back from extinction could have an important beneficial impact on the vegetation of its habitat.

26 Our current efforts at preserving biodiversity are insufficient.

List of People

A Ben Novak

B Michael Archer

C Beth Shapiro

2剑桥雅思15Test2阅读Passage2原文翻译

我们应该让灭绝的物种复活吗?

A 旅鸽是一个有着传奇色彩的物种。它们常常成群结队地飞越北美，每一群中可能有数百万只，它们的迁徙曾是大自然中的一大奇观。遗憾的是，旅鸽在1914年9月1日灭绝了，那天，最后一只活着的旅鸽在辛辛那提动物园死亡。遗传学家Ben Novak是一个宏大项目的首席研究员，该项目旨在通过一种被称为“去灭绝”的过程使这一鸟类重获新生。该过程的基本假设是利用克隆技术将已灭绝动物的DNA转化为受精胚胎，再由其现存的近亲(在旅鸽的例子中就是现存数量众多的斑尾鸽)携带，然后就会作为一只活生生的、会呼吸的动物出生了。旅鸽是这一领域中的先驱物种之一，但它们绝不是用来试验这项技术的物种。

B 在澳大利亚，袋狼，通常被称为塔斯马尼亚虎，是基因科学家们正在努力复活的另一柿已灭绝生物。新南成尔士大学的Michael Archer解释说：“在塔斯马尼亚岛，现在还没有含内动物能够填补袋狼曾经占据的生态位。”他指出，袋狼灭绝后的几十年里，种会“使生物极度衰弱”的面部肿瘤综合征的传播威胁到了袋獾的生存，而袋獾是岛上另一个臭名昭著的物种。袋狼本可以阻止这种疾病的传播，因为它们会杀掉大量的袋獾(以阻断传播)。他说：“如果这种传染性恶性肿瘤在之前就出现了，那么它可能已经在开始的地区消失了。所以袋狼回到塔斯马尼亚岛会有助于确保袋獾不再遭受这种风险。”

C 如果灭绝的物种可以重获新生，那人类就能开始修正他们在过去几千年里对自然界造成的破坏了吗?加州大学圣克鲁斯分校基因组研究所的Beth Shapiro说：“‘去灭绝’的理念是我们可以通过让不再存在的物种复活来逆转这个过程。但我不认为我们能做到这一点。我们不可能带回与很久之前就已经灭绝的物种百分之百相同的生命。”对于灭绝已久的物种来说，一个更实际的方法是将现有物种的DNA作为模板，在其中插入灭绝动物的DNA链创造出新的生命——一种以现存物种为基础的杂交动物，但其外表和或行为会与该灭绝动物的很相似。

D 这个复杂的过程和未必可靠的结果引出了一个问题：这项技术的实际意义是什么? Novak解释说：“对我们来说，我们的目标一直都是找到一个合适的物种来替代已灭绝的物种。当斑尾鸽繁殖的时候，它们在每公顷范围内可能会分散筑一到两个巢，而旅鸽是比较喜欢群居的，它们在每公顷范围内可能会筑一万个或者更多的巢。”自从这个重要的物种消失后，美国东部的生态系统就受到了影响，因为缺少成千上万的旅鸽毁坏树木和树枝而对森林造成的干扰，就意味着森林对再生长的需求很低。这使得森林的生态结构停滞不前，因此也就不需要其他进化而来的动植物帮助受到干扰后的森林再生了。据Novak所说，一只杂交的斑尾鸽会带有旅鸽的筑巢习性，理论上就可以恢复对森林的干扰，从而为许多其他当地物种的繁衍创造一个必要的栖息地。

E 这项技术的另一个热门候选物种是猛犸象。哈佛医学院教授兼猛犸象复活计划的负责人George Church一直在重点研究猛犸象的抗寒体质，这是已灭绝的猛犸象和它现存的近亲亚洲象之间的主要区别。该项目的目标是通过确定使猛犸象能够在冰原的寒冷气候中生存下来的基因特征，来让猛犸象或一种类似于猛犸象的物种重返该地区。Church说：“我目前的首要任务是保护濒危的亚洲象，将它们的活动范围扩大到冰原庞大的生态系统中。为此它们要经历一些必要的演化，包括为了减少它们在冰原的热量流失，而进化出更小的耳朵、更厚的皮毛、额外的隔绝寒冷的脂肪层，以及在现已灭绝的猛犸象身上发现的所有特征。”在欧亚大陆和北美的冻土地带和北方森林中，这种大型哺乳动物的重生也可能会是减少碳排放量的一个有利因素-大象在雪地上打洞并撞倒树木，从而促进草类的生长。而草类生长会降低温度，并减少冻土层消融时所产生的排放物。

F 复活灭绝动物的想法引人遐思，但显然，试图拯救一个目前只是面临着灭绝威胁的现存物种要容易得多。Shapiro解释说：“许多人们在思考“去灭绝”的时候想到的技术都可以用于“基因拯救”。”她更倾向于将争论的焦点首先集中在如何利用这种新兴技术来充分理解各种物种灭绝的原因，以及如何利用它来进行基因改造，以防止未来出现大规模的灭绝。她接着说：“我还想说，什么都不做是极不道德的。我们知道现在做得还不够，就算有一些计算得出的、衡量得到的风险，我们也要愿意承担。”