KeystoUnitEight讲解

1、Unit Eight参考译文基因、环境与双胞胎1 遗传与环境究竟哪一个影响更大呢 ? 在相当大的程度上， 一个人生来具有的潜力将决定 他一生的作为。 因此遗传即命运，是命中注定的东西。然而， 基因并不是在真空中发挥作用 的；一旦我们开始认识到基因在个人发展中所起的作用， 我们就会明白， 没有与其相互作用 的环境，就不可能有任何个人的发展。没有一个特点是完全由环境或者完全由基因造成的。2 遗传和环境的相对影响在同卵双胞胎中最易观察到。大多数的同卵双胞胎是在一起抚养 长大的， 因而无论在外表还是行为上都惊人地相像。 这些实例证明， 若在同样的环境中抚养 成长，具有相同基因的个体就会以几乎同样的方式

2、对环境作出反应。 但这些例子并不能说明 如果把这些同卵双胞胎分开抚养会发生什么情况。3 对分开抚养的同卵双胞胎已进行了许多研究。被研究的这些双胞胎都生活在美国，成长 的自然环境几乎相同，并且具有几乎相同的营养史。因而，正如所料，他们在外表、身高和 体重上极其相似。也有例外：一对双胞胎中的一个患了相当严重的疾病而另一个却没生病。 但是总体而言， 同卵双胞胎， 甚至从婴儿时就分离的同卵双胞胎， 在心理和身体上会如此相 似，给每个人留下了深刻的印象。4 在对从一出生就分离的 19 对双胞胎的研究中，研究者发现，其中约三分之二的双胞胎 之间的差异与一起长大的双胞胎之间的差异一样不明显。 这有力地说明了

3、基因的影响力和环 境作用的局限性。 然而， 必须记住的是， 尽管被研究的同卵双胞胎生活在不同家庭里且相距 甚远， 但总体而言， 那些家庭的环境基本上没有什么差异。 通常都会千方百计地将每个孩子 安置在和他自己原来的家庭背景类似的家庭里， 因而发现这些双胞胎成长中有不少相似之处 就不足为奇了。 但是在那些分开抚养的双胞胎的生长环境有较大差异的实例中， 双胞胎之间 的差异就很大。下面的例子说明了在对比度很大的环境中成长的同卵双胞胎的情况。5 格莱迪丝和海伦出生于俄亥俄州的一个小镇，在大约 18 个月时被分开抚养。她们直到28 岁才再次相遇。海伦被领养了两次。她最初的养父母靠不住，两年后海伦又被送回

4、到孤 儿院。 过了几个月， 她再一次被住在密歇根东南部的一对农场主夫妇领养。 此后 25 年她一 直住在那里。 她的第二个养母尽管本身没受过什么教育， 却下决心要让海伦得到良好的教育。 海伦最终大学毕业，教了 12 年书， 26 岁结婚，并有了一个女儿。6 格莱迪丝被加拿大的一个列车乘务员及其妻子领养。她读三年级的那一年，全家搬到了 加拿大落基山脉一带一个相当偏僻的地方， 那儿没有学校， 格莱迪丝的正式教育也就此结束， 直到全家搬到安大略省后才得以继续。于是格莱迪丝就呆在家里干家务，一直到她 17 岁， 随后在一家针织厂工作。 19 岁那年她去了底特律，找到一份工作， 21 岁时结了婚。7 海

5、伦在儿童和成年时期都一直比格莱迪丝健康，但除了这一点以及各自所受的教育不同 之外，她们的生活环境十分相似。她们的体重、身高、发色和牙齿都十分相似。她们之间的 区别显然与她们各自的家庭生活和社交生活不同有关。8 海伦自信、举止得体、充分利用了她外表的优势，在社交中也显得有修养，很从容。格 莱迪丝则害羞、 忸怩、 沉默寡言， 缺乏迷人或优雅的风度。 一位研究她们的科学家说： “这 两个双胞胎之间的悬殊差异真可谓是大学教育的颇有说服力的广告。 ”9 考虑到她们环境方面的经历的本质不同，海伦和格莱迪丝之间的差异也就不足为怪了。 由于心理特点在很大程度上取决于经历， 可想而知心理特点也反映经历。 另一方

6、面， 那些不 易受环境影响的特点更有可能在同卵双胞胎中表现出高度的相似性。 尽管基因十分重要， 但 是基因本身决不能完全决定任何一个特点。 我们的能力会达到什么程度由基因注定， 而我们 真正做了什么则主要由环境决定。ExercisesPost-ReadingReading Comprehension 1 1 Introduction (Para. 1) No characteristic is caused exclusively by either environment or genes.2 Research on the relative effects of heredity and

7、environment (Paras. 2-8).A Studies on identical twins raised together (Para. 2) Findings: They are remarkably alike in both appearance and behavior.Implication: Individuals with the same genes, when raised in the same environment, will respond to it in much the same way.B Studies on identical twins

8、raised apart in similar environments (Paras. 3-4) Findings: They exhibited great psychological and physical likenesses.Implication: This does not inform us of the power of genes and the limitation of the effect of the environment.C Studies on identical twins raised apart in contrasting environments

9、(Paras. 5-8)Findings of a case study on Gladys and Helen:Their similarities: Their weight, height, hair color, and teeth were very similar.Their differences in personality: Helen was confident, graceful, made the most of her personal appearance, and showed considerable polish and ease in social rela

10、tionships; while Gladys was shy, self-conscious, quiet and without charming or graceful manners.Implication: Genes alone are never absolutely responsible for any trait.3 Conclusion (Para. 9)What we can do is set by the genes, but what we actually do is largely determined by the environment.2 1 F 2 F

11、 3 F 4 F 5 T 6 T 7 F 8 T Vocabulary1 1 C 2 A 3 C 4 C 5 A 6 B 7 B 8 B2 1 resemble 2 alike 3 Like 4 similar 5 same 6 Identical, same, alike3 1 absolutely 2 eventually 3 obviously 4 Similarly5 remarkably 6 approximately 7 exclusively 8 actually Translation1 There are nearly 24 reported sets of twins in

12、 the town, of which nearly 12 are identical twins.2 “ Wea re well aware of this danger and won tb lindly accept what people say ”s, tated Mr. Malcom.3 I still remember when I first met you on the lake side; what you gave me, all that you gave me.4 When she came to writing her college project, she fo

13、und other material; this would enable her to enjoy more fully the work.5 As soon as the 15 minutes rest is over, you must start the next exercise to make the exerciseprogram more effective.6 Without their working as volunteers, we would never be able to provide any service for those who need it.7 Pe

14、ars are treated in much the same way as some other kinds of fruit but are never wrapped.8 A similar meeting held at the beginning of the year, attended by 60 people including teachers, nurses and doctors, was very successful according to the report.After-Class Reading参考译文科学再次关注双胞胎1 如果你对双胞胎感兴趣的话，那么双胞

15、胎镇会使你着迷。2 从 1976 年起的每个夏天，这个位于俄亥俄州克里夫兰郊外的小镇都会挤满众多的双胞 胎。去年夏天，有 2,356 对双胞胎从世界各地来到这里，参加并观看游行、焰火、魔术表 演、五公里赛跑以及一百多项比赛：评选出年纪最大的、年纪最小的、最像的、最不像的， 以及两人相加笑起来嘴咧得最大的双胞胎。3 你要是去过那儿的话，你可能会注意到有很多科学家也参加了这个盛会。有些科学家是 来寻找引起疾病的缘由例如皮肤病、 癌症、心脏病。 另外一些科学家则对双胞胎自身的 感受感兴趣。 但是在所有的科学家中， 从事最重要的也是最有争议的工作的是这样 一些科学家， 他们专门研究先天遗传和后天培养这

16、个由来已久的问题， 即研究有关我们是如 何成为现在这个样子的。4 为什么我们有些人精通数学或擅长写作，而另外一些人则在艺术或篮球上出类拔萃？是 什么造成了我们在智力、 才能和品味上的差异？这些主要是由我们从父母那里继承来的基因 （先天遗传）决定的吗？同我们的生活经历（后天培养） ，也就是我们成长的社会环境又 有多大关系呢？5 如果你是一个对这个问题感兴趣的科学家，你难道不想研究一下同卵双胞胎吗？想想看 吧，从同一受精卵发育出来了两个人。也就是说， 两个人有完全相同的基因。同卵双胞胎之 间存在的任何不同都只能是他们成长环境不同的结果。 但是你能说他们之间的任何相同点都 是基因相同的缘故吗？6 也

17、不一定。记住，大多数双胞胎都有相似的成长环境同样的房子，同样的饮食，同 样的亲戚等等。 研究分开在不同环境下抚养的同卵双胞胎， 或许是你能准确衡量先天遗传和 后天培养所起的作用的唯一办法。7 在过去的 10 年间，由心理学家小托马斯 J. 布沙尔带领的一组科学家研究了大约65 对分开抚养的同卵双胞胎。他们还研究了大约 45 对分开抚养的异卵双胞胎。8 科学家们把每对双胞胎带到明尼苏达大学进行为期一周、深入细致的检测。小组里的医 生和牙医们给这些双胞胎进行了全面的体检。他们记录了双胞胎的身高、体重、眼睛颜色、 耳朵的形状和头围。9 同时，心理学家们还对双胞胎进行了智商和性格测试。为了测试性格，心

18、理学家们设法 测定了双胞胎们对事情担忧的程度， 他们是谨慎型的还是鲁莽型的， 以及他们的创造力如何。 他们根据双胞胎们对一些陈述的回答来衡量这些方面以及其他一些性格特征， 这些陈述包括 “我很少鲁莽行事” , “木柴燃烧的火焰激发我的想象力”等。一周结束时，每个双胞胎 都回答了大约 15,000 个问题。10 布沙尔小组对分开抚养的双胞胎之间的相似之处感到非常吃惊。 例如他们的手势和姿势 经常惊人地相似。 在照片上， 很多双胞胎摆出的姿势几乎一模一样。 有些同卵双胞胎还发现 他们的生活方式极其相似。11 “吉姆兄弟” 是布沙尔研究的第一对同卵双胞胎， 他们出生四周后就被不同的家庭领养。 他们都

19、在俄亥俄州长大， 彼此相隔 45 英里。当他们在 39 岁重逢时， 发现了一系列惊人的 相同之处： 两个人都叫吉姆，都开同一型号的蓝色雪佛兰，都喜欢做木工， 都有啃手指甲的 习惯，养的狗都叫“ Toy ” 。两个人都有傍晚头痛的毛病，都是在 18 岁时开始的。12 吉姆兄弟之间所发现的相同点在明尼苏达小组研究的双胞胎身上普遍存在。 有些对明尼 苏达研究工作持批评态度的人说“这些巧合没什么可奇怪的” 。他们认为每个人的生活里 都有很多的细节， 因此必然会有巧合。 而且， 对于异地抚养的同卵双胞胎之间发现的任何一个巧合， 持怀疑态度者都能指出大量未被发现的不同点。同一对双胞胎可能有不同型号的电视机

20、，支持不同的足球队。但不同点是不会被报道的，因为它们不会使人吃惊。13 但是除了巧合之外， 明尼苏达的科学家们收集并分析了有关双胞胎的健康、 智力和个性 方面的大量数据。布沙尔认为，有关异地抚养的同卵双胞胎的数据清楚地显示，先天遗传， 即我们所继承的基因，对我们的生活有显著的影响。该小组发现，这些同卵双胞胎在身高、 指纹和心率等生理特征方面极其相似。 成年的同卵双胞胎还往往有相似的病史， 例如同时得 了青光眼。14 明尼苏达小组报告说智力似乎也更受基因的影响而不是环境。 虽然由不同的家庭抚养长 大，布沙尔小组研究的同卵双胞胎在成人智力测验中所得的分数完全相同或几乎相同。15 但是最令人吃惊的是

21、， 明尼苏达小组发现基因对于个性的形成起着重要作用。 例如， 基 因会决定我们是否尊重传统、 循规蹈矩， 还是会成为坚定的离经叛道者。 根据布沙尔的看法， 你与生俱来的基因对你是否自信、 快乐、乐观或者对世界上的事是否持消极态度有很大影响。 明尼苏达小组的一位心理学家南希 西格尔说： “这项研究令人信服地表明：基因影响 人们行为的每个方面。 ”16 另一些科学家不同意这个说法。 他们质问， 既然对智力的定义就多种多样， 你们又怎么 能够去研究智力是否是遗传的呢？他们认为同样的问题也存在于其他的性格特征中。17 布沙尔本人表示了这样的观点：即使是他所研究过的最相似的双胞胎也是彼此不同的。 因此即

22、便基因对我们的生活有很大的影响， 它们也不是唯一起影响作用的因素。 我们的日常 经历也有助于塑造我们。18 你知道这意味着什么：为了考试，你还得学习！PART 3 Further Development1 Vocabulary Review1 B 2 A 3 A 4 A 5 B 6 B 7 B 8 C 9 B 10 A 11 B 12 CExplanations of the italicized words1 A likely to develop into a particular type of person or thing in the futureB a natural abili

23、ty or quality that could develop to make sb. / sth. very goodC the possibility that sth. will develop in a particular way, or have a particular effect2 A show clearly that sth. is true or that it existsB show or describe how to do sth. or how sth. worksC protest or support sth. in public with a lot

24、of other people3 A make sth. stay the same; keepB strongly express your belief that sth. is trueC keep a machine, building, etc. in good condition by checking and repairing it regularly4 A relating to the body rather than the mindB relating to real objects that you can touch, see, or feelC according

25、 to the laws of nature5 A start to deal with or think about sth. in a particular wayB take sb. else s child into your home and legally become its parentC formally approve a proposal, amendment, etc., especially by voting6 A a comment you madeB say sth., especially about sth. you have just noticedC s

26、th. that you say when you express an opinion or say what you have noticed7 A give back or show an image of; mirrorB show or be a sign of a particular situation or feelingC think carefully about sth.8 A an action, especially an official one, that is intended to deal with a particular problemB find th

27、e size, length, or amount of sth., using standard unitsC judge the importance, value, or true nature of sth.9 A receive a particular amount of money for the work that one doesB get sth. as a result of your efforts or your behaviorC earn our keep: a phrase meaning“ do jobs in return for being given a

28、 home and food10 A not very great, big, or expensiveB (a girl) avoid doing or wearing anything that might cause men to have sexual feelings toward her C not proud11 A show sth. in a public place so that people can go to see itB clearly show a particular quality, emotion, or abilityC sth. put on publ

29、ic display12 A lay open to danger or harmB show sth. that is usually covered or hiddenC make it possible for sb. to experience new ideas, ways of life, etc.2 What Do You Know?STEP ONE1 CDNA is short for deoxyribonucleic acid (de-oxy-ri-bo-nu-cle-ic acid). DNA is a chemical in every cell of your body

30、. It is shaped like a long, twisted ladder. This shape is called a double helix.2 CDNA is found in all living things. This amazing chemical tells each cell what to do and determines what an organism will look like.3 CScientists are still debating how nature and nurture work together to make you who

31、you are, but most agree that both play a role.4 BScientists used to think that humans have about 100,000 genes. Recently, it was discovered that we have about 10,000 to 20,000. We carry two copies of every gene, one copy from each parent.5 CMany things, such as what you eat, can affect how tall you

32、ll grow. Even if you have talent,making art takes practice. But eye color is a trait passed on through genes.6 BBefore Dolly, scientists used different techniques to clone animals. Dolly was the first animal to be cloned from a cell of an adult mammal.7 CBelieve it or not, humans and chimps have a l

33、ot of DNA in common! But as you can see, even small differences in genetic codes can make big differences in what an organism looks like.8 BYou can t telyl blooking at a fruit fly and a human, but they have a lot of similar DNA. In fact, scientists study the fruit fly genes to help advance medical k

34、nowledge.9 BThe human genome has a lot of DNA that carries no information and is not active genetically. It s still a mystery to scientists why this DNA is there and what it does.10 CAlthough they can have very different personalities, identical twins are often difficult to tell apart physically. Bu

35、t the fingerprints of each are unique.STEP TWOSampleEvery day you hear people talking about DNA, but what do you know about DNA and how it is related to our life? Let me tell you briefly.DNA is the short form of deoxyribonucleic acid. It is a chemical in every cell of our body, in the shape of a dou

36、ble helix. DNA is found in all living things. This amazing chemical tells each cell what to do and determines what an organism will look like. Scientists used to think that humans had about 100,000 genes. Recently, it was discovered that we have between 10,000 to 20,000 human protein-coding genes. W

37、e carry two copies of every gene, one copy from each parent. Living beings depend on genes, as they specify all proteins and functional RNA chains. Genes hold the information to build and maintain an organismgense tcice ltlrsa aitns dto p oafsfspring.All organisms have many genes corresponding to va

38、rious biological traits, some of which are immediately visible, such as eye color, or number of limbs, and some of which are not, such as blood type or increased risk for specific diseases, or the thousands of basic biological processes that comprise life. Genes, to a large extent, decide who we are

39、, what we look like, and what we can do, but, of course, the environment we live in also plays a part.Believe it or not, humans and chimps, the closest living relatives to humans, have a lot of DNA in common (about 98%)! But as you can see, even small differences in genetic codes can make big differ

40、ences in what an organism looks like.Presently, only the function of a few percent of the DNA is known, the rest has been believed tobe useless garbage, commonly called “Junk DNA” increasingevidence indicating that this DNA is not“roles, which means that this so- called “-nconding DNA the “ codingD

41、NA”, in important ways. However, the DNA.by molecular biologists. There is nowjunk ” at all. It has been found to have various regulatory ” influences the behavior of the genes, knowledge is still incomplete about thisAnd there is little knowledge about the relationship between non-coding DNA and th

42、e DNA of genes. I believe scientists will tell us more with the furthering of their research.Teaching tipsStrategies for giving a speechPART ONEThroughout history people have used public speaking as a vital means of communication. Pericles, the Greek leader, said more than 2,500 years ago,“One who f

43、orms a judgment on any point butcannot explain it clearly might as well never have thought at all on the subject.” The samtoday. The ability to clearly and effectively communicate your thoughts and ideas is important in both your personal and professional life. Personally, it can help you develop de

44、eper and more fulfilling relationships of all types. Professionally, it can help you stand out among yourcolleaguesand attain positions of leadership and influence.The following are some basic concepts of a speech:Organization:BeginningObjectives? Get the attention and interest of your audience;? Re

45、veal the topic of your speech;? Establish your credibility (you are qualified to speak on a given topic) and good will;? Preview the body of the speech.Devices? Relate the topic to your audience;? State the importance of your topic;? Startle the audience with an arresting and intriguing statement;?

46、Arouse the curiosity of the audience;? Question the audience;? Begin with a quotation;? Tell a story;Body Main Points? Number of main points: make a few main points stand out and be remembered;? Strategic order of main points: chronological order, spatial order, causal order, problem-solution order,

47、 topical order, etc. Ending Purposes? Signal the end of the speech;? Reinforce the central idea.(To be continued)Ending Devices? Summarize your speech;? End with a quotation;? Make a dramatic statement;? Refer to the introduction;Supporting evidence:Examples TypesBrief examples? A brief example may

48、be used to introduce a topic.? You can pile them one upon the other until youcreate the desired impression.Extended examplesA story, narrative, or anecdote developed at some length to illustrate a point.Hypothetical examplesAn example that describes an imaginary or fictitious situation.Statistics? U

49、se representative statistics;? Choose statistics from a reliable source;? Use correct statistical measures.Testimony Types1? Expert testimony;? Peer testimony: first-hand experience on the topic.2? Direct quoting;? Paraphrasing: expressing by using different words, especially in order to make it sho

50、rter or clearer.Presenting the speech:Language Use language accurately and appropriately.DeliveryVoice Volume, pitch, rate, pauses, vocal variety, articulation, etc.BodyPersonal appearance, movement, gestures and postures, eye contact, etc.VisualaidsTips? K eep visual aids simple;? Make sure visual

51、aids are large enough;? Use a limited number of slides;? Display visual aids only when discussing them;? Talk to your audience, not to your visual aids;? Explain visual aid s clearly and concisely.(Continued)PART TWOFind two sample speeches, one to inform and the other to persuade, and 1) analyze th

52、e scripts together with the students in terms of the organization and the supporting evidence used; 2) watch the speeches to see how the speakers present the speeches.PART THREEAsk the students to work in groups, with each group preparing a speech, either an informative speech or a persuasive speech

53、. Each group chooses one representative to deliver it to the whole class. Then invite comments from the whole class, using the concepts presented in PART ONE. 3 Relating Your Own ExperienceSample1 Both my parents were occupied with working so I was raised by my grandparents. They were kind to me. Th

54、ey talked to me a lot, especially my grandmother. They told me about their personal experiences, and what it was like when they were young and when my parents were children.2 My parents told me many stories and most of them were famous legends. The story that impressed me most was about a courageous

55、 orphan. Every day, he would go out to cultivate his land. One day when he came home, he found a delicious meal on the table. This happened several times. In order to find out who was cooking for him, the young man hid behind the door. He discovered that it was the oyster fairy who had been sent to

56、take care of him. From then on, the good fairy and the orphan lived happily together.3 Yes, but I also enjoyed doing things with them. While doing things with them, we not only talked a lot, I also learned a lot of practical skills.4 I think it helped to cultivate my morality. I am honest and hardwo

57、rking. I think they made me strong and courageous.?1 Yes, my parents talked to me a lot, especially my father. They believed that boys should be with their fathers more to be manly. As you can imagine, my father often taught me how to behave like a man. He also told me stories about brave men, about

58、 the universe, and about his college life. When we were together, he often treated me as his equal, rather than a kid. I really enjoyed that.2 My father graduated from an army institute so he told me a lot of stories about his college life, quite different from what we re having now. There is one story that really impressed me, andevery time I recall it, I can t help laughing. Students in an army institute ha