英语选修八小课文及翻译第二单元

Unit2 THE RETURN OF THE DINOSAURS? 恐龙的回归？The possibility of cloning fierce and extinct wild animals has always excited film makers. 克隆凶猛和灭绝的野生动物的可能性一直使电影制片商感到兴奋。And they are not the only ones! 然而他们并不是唯一对此感到兴奋的人。The popularity of films such as Jurassic Park, in which a scientist clones several kinds of extinct dinosaurs, proves how the idea struck a mixture of fear and excitement into peoples hearts. 在侏罗纪公园这部影片中，有一位科学家克隆了好几种不同的绝种恐龙。类似这样的电影很受欢迎，证明了这一想法使人们感到既兴奋又恐惧。But in fact we are a long way from being able to clone extinct animals. 但事实上，想要克隆绝种动物，我们还要很长的路程要走。Scientists are still experimenting with cloning mammals. 科学家们现在还在进行克隆哺乳动物实验，This is because the cloning of mammals is still a new science and its story only began seriously in the 1950s as this list shows:这是因为克隆哺乳动物仍然还是一门新的科学，它是从20世纪50年代才开始进行认真研究的，如下表所示：1950s cloning of frogs 1996 first clone of a mammal: Dolly the sheep 20世纪50年代：克隆青蛙 1966年：首次克隆哺乳动物(多莉)1970s research using the embryos of mice 2000 cow gave birth to a bison 20世纪70年代：用老鼠胚胎进行研究 2000年：母牛生野牛1979 work on embryos of sheep and mice 2001 Chinas first cloned twin calves 1979年：对羊和老鼠的胚胎进行研究 2001年：中国首次克隆出双胞胎小牛1981 first experimental clones of mice 2002 first cloned cats 1981年：首次对老鼠进行实验性的克隆 2002年：首次克隆猫1983 first experimental clones of cows 2005 first cloned dog 1983年：首次对母牛进行实验性的克隆 2001年：首次克隆狗From time to time people suggest that extinct animals like dinosaurs, can possibly be brought back to life through cloning. 不时地会有人提议，克隆技术将有可能使地球上已经消失的动物（如恐龙）复活。Unfortunately, with what we know now, this is either impossible or unsuitable. There are many reasons.不幸的是，据我们现在所知这是不可能的，也是不合适的。其原因有很多： The initial requirement is that you need perfect DNA (which gives information for how cells are to grow). 首先要求你有完好的DNA，以提供有关细胞将如何生长的信息。 All efforts of cloning an animal will be in vain if there is not enough diversity in the group to overcome illnesses. 如果某个动物群体没有足够的多样性以战胜疾病，那么克隆这种动物的所有努力都将是无用的。Diversity in a group means having animals with their genes arranged in different ways. 群体的多样性是指这群动物的基因要以不同的方式排列。The advantage is that if there is a new illness some of these animals may die, but others will survive and pass on the ability to resist that disease to the next generation. 其优点是，如果发生了某种新的疾病，这类动物中的一些可能会死去，而另外一些却能存活下来，并且把这种免疫力传给下一代。The great drawback to cloning a group of animals is that they would all have the same arrangement of genes and so might die of the same illness. Then none of them would be left to continue the species. 经过克隆的动物群体的最大缺点是：它们的基因排列有可能完全相同，因而它们有可能会死于同一种疾病，这样它们也可能一个也留不下来传种接代了。 It would be unfair to clone any extinct animals if they were to live in a zoo. 你如果克隆出任何绝种动物，而它们必须生活在动物园里那是不公平的。A suitable habitat would be needed for them to lead a natural life. 它们需要适当的栖息地过正常的野生生活。Based on what we know now, you cannot clone animals that have been extinct longer than 10,000 years. 就我们现在所知，你不可能克隆那些已经绝种了一万年以上的动物。Actually, dinosaurs