Unit 7

Research into Population Genetics

Background Information Luca Cavalli-Sforza: Cavalli-Sforza, born in Genoa, Italy, was

educated at the University of Pavia where he gained his MD in 1944. After working on bacterial genetics at Cambridge (1948 － 1950) and Milan (1950 －1957) he has held chairs in genetics at Parma (1958－ 1962) and Pavia (1962 － 1970). In 1970 he was appointed professor of genetics at the University of Stanford, California, a position he held until his retirement in 1992. Cavalli-Sforza has specialized mainly in the genetics of human populations, producing

with Walter Bodmer a comprehensive survey of the subject in their Genetics, Evolution and Man (1976). He has also done much to show how genetic data from present human racial groups could be used to reconstruct their past separations. This reconstruction, based on the analysis of 58 genes, yields a bifurcated evolutionary tree with Caucasian and African races in one branch and Orientals, Oceanians, and Amerinds in the other.

Background Information:

Columbus:

Christopher Columbus, an Italian-born master navigator (born in Genoa, Italy in 1451 and died at Valladolid, Spain in 1506) who sailed in the service of Spain, is commonly described as the discoverer of the New World—America. His four transatlantic voyages (1492-1493, 1493-1496, 1498-1500, and 1502-1504) opened the way for European exploration, exploitation, and colonization of the Americas.

Columbus’s real greatness lies in the fact that

having found the West Indies — making major

errors in his navigational computations and

location in doing so — he was able to find his way

back to Europe and return to the India. It is as a

result of Columbus’ “discovery” that the New

World became part of the European world.

Background Information

The human genetic map:

Our bodies are comprised of trillions of microscopic units called cells. Cells in turn are built up from many specific types of molecules, both large and small. The large molecules or macromolecules include polysaccharides, nucleic acids and proteins. Proteins are the workhorses of our cells. There are about 40,000 different types of proteins in our bodies. Each protein is present in many, many copies.

An adult, for example, carries about a billion trillion hemoglobin molecules. The flow of genetic information is from DNA to RNA to Protein. Each protein is a linear polymer of a specific sequence of 20 different amino acids. DNA is also a linear polymer comprised of 4 types of nucleotides. The sequence of amino acids in each protein is encoded by a segment of DNA called a gene. Three consecutive nucleotides in a gene encode a single amino acid in the corresponding protein. The genetic code is universal among all living things.

Background Information: Khoisan:

Khoisan is the name by which the lighter

skinned indigenous peoples of southern Africa, the Khoi (Hottentots) and the San (Bushmen) are known. These people were the earliest inhabitants of Africa and dominated the sub-continent for millennia before the appearance of the Nguni and other black peoples. There were probably about 120,000 living in South Africa around 1500.

Background Information Basques: The Basques are a people who live in a small

region (about the size of Rhode Island in the United States) that straddles the border of Spain and France from the sea in the west into the Pyrenees in the east. This area is called Euskal Herria (comprising seven provinces, historically: Araba, Bizkaia, Gipuzkoa, and Navarra on the Spanish side; Laburdi, Zuberoa, and Behe-Nafarroa on the French side).

There are about 660,000, according to the 1991 census. Fewer than 80,000 of these are on the French side of the frontier which runs through the Basque Country, the rest on the Spanish side. Basques speak a language called euskara, but today only about 25% of the population is fluent in that tongue. Even so, the word for a Basque person, euskaldun, means “possessor of the Basque language”. The Basque population is distinguished physically by a high incidence of Rh Negative factor in the blood.

No one knows exactly where the Basques came

from. Some say they lived in that area since Cro-

Magnon man first roamed Europe. Estimates of how

long they have lived there vary from 10,000 to

75,000 years. Some say they are descended from

the original Iberians. More fanciful theories exist, as

well. One is that the Basques are the descendents

of the survivors of Atlantis.

Text Structure Analysis:

Part I (Para. 1-2):

The book The History and Geography of

Human Genes proves that the “races”

are alike under the skin and creates the

first genetic map of the world, the

closest thing we have to a global family

tree.

Part II (Para. 3-4):

It took decades and pains for scientists to

collect the information needed to draw the

family tree.

Part III (Para. 5-9):

The book’s four remarkable discoveries:1)A color map of genetic variation has Africa at

one end of the range and Australia at the other;

2)Africa was the birthplace of humanity; 3)the genetic maps show the origins of

populations; and 4)genetic information is also the latest raw

material of the medical industry.

Part IV (Para. 10):

Apart from scientific purposes of the research, its social objective is to weaken conventional notions of race that cause racial prejudice.

As the most extensive survey to date on how humans vary at the level of their genes, the book The History and Geography of Human Genes made two remarkable contributions to science: There is no scientific basis for the genetic superiority of one race over any other one; and it creates the first genetic map of the world. In the process of collecting information for the book, however, scientists encountered great difficulties. The ultimate goal of their work is to remove racial prejudice.

Summary of the Text:

Words and Expressions

extensive to date nothing less than migrate be confined to as of in effect assume adapt to indicate shed light on conventional

The baby was put through extensive tests during a 10-day stay.

他们让这个婴儿住院 10 天接受了全面的检查。

The function of the victories in providing the regime with even more extensive popular backing seems undeniable.

这些胜利为该政权提供了更为广泛的支持，这一点似乎是不可否认的。

1. extensive: a. including or dealing with a wide range of information （ Para. 1 ）

2. to date: until now (Para. 1)

To date, research has focused on cell multiplication.

迄今为止，研究已经集中到细胞繁殖上。

There is no evidence, to date, that making people belt up turns them into worse drivers.

至今仍没有迹象表明司机们系安全带会影响驾驶。

3. nothing less than: exactly the same as (Para. 2)

You’re nothing less than a murderer. 你简直是一个杀人犯！

The present trend is nothing less than alarming.

当前这种趋势确实令人担心。

4. migrate: move from one place to another (Para. 2)

Mexican farm workers migrate into the U.S. each year to find work at harvest time.

墨西哥农场工人每年有大批外出去美国，希望能在丰收季节找到工作。

In September these birds migrate 2,000 miles south to a warmer climate.

九月，这些鸟向气候温暖的南方迁徙 2000 英里。

5. be confined to: be restricted or kept within certain limits or time (Para. 3)

So far, fighting has been confined to the capital.

到目前为止，战斗仍没有超出首都的范围。

Disasters of this sort were confined to neither traditionally flooded land nor the winter months.

这种灾难不只发生在洪水泛滥的地区，也不只发生在冬季。

6. as of: starting from (Para. 3)

As of the first of July, all back seat passengers must wear seat belts.

从 7 月 1 日起，所有后座上的乘客必须系安全带。

The new timetable will come into effect as of January 2003.

新的时间表将从 2003 年 1 月起生效。

7. in effect: in fact (Para. 3)

What the management is saying, in effect, is that they are going to stop recruiting new staff.

管理层的实际意思是，他们将停止招聘新员工。

In effect, your sister is making a fool of you. 事实上，你妹妹在愚弄你。

8. assume: think or accept that sth. is true but without proof of it (Para. 5)

If you are rude to other people, your child will assume that this kind of behavior is acceptable.

如果你对别人不礼貌，你的孩子就会认为这样做是可以的。

In other academic areas it is assumed that the teacher knows more than the student.

在其他学术领域，人们都想当然地认为老师总是比学生知道的多。

9. adapt to: change in order to deal more successfully with a new situation (Para. 4)

In deeper waters, dwells an astonishing range of creatures adapting well to great pressures, extreme darkness, and a food supply only available there.

在深水区居住着种类惊人庞大的生物，它们能适应巨大的压力，极度的黑暗和有限的食物。

Old buildings and streets, well cared for and adapted to today’s needs, vastly enhance the quality of life.

古老的建筑和街道被很好地维护和调整以适应今天的需要，这大大地提高了我们的生活质量。

10. indicate: v. be a sign of; show that sth. is possible or likely (Para. 9)

These responses indicate that there is a general feeling of dissatisfaction among voters of all age groups.

这些回应表明，各个年龄层的投票者都有一种普遍的不满情绪。

Mr. Meacher indicated that a Labour government would be likely set up new industrial courts.

米彻先生表示，工党政府将可能成立新的工业法庭！

11. shed light on: make a problem easier to understand (Para. 7)

Scientists working in the Gobi desert have shed new light on the life of dinosaurs.

在戈壁滩上工作的科学家们对恐龙的生活有了新的认识。

The research is expected to shed light on the social consequences of cities’ changing economic roles.

这一研究希望弄清城市不断变化的经济角色所带来的社会影响。

12. conventional: a. following what is traditional or considered to be normal (Para. 10)

The house was built with conventional materials.

这房子是用传统的材料建造的。

They are a conventional family. 他们是一个传统的家庭。

Questions for Discussion:

1. How did the researchers obtain the

information to write their book?

2. What two scientific aims does the book have?

Writing: A Letter of Self-recommendation (自荐信 )

1.阐明你欲深造的专业2. 阐述你的学业背景……3. 表明在此深造的目的和理由

写作模式（ 1 ）

1) With four years of my college life devoted entirely to…, I am thrilled to find myself particularly interested in... 2) To make an outstanding researcher of me in this field, however, I am very conscious of my inadequacy in… and so strongly motivated to pursue a master’s degree in the Department of… at your University.

写作模式（ 2 ）

3) Fully aware of the importance of solid academic foundation to my professional pursuit, I committed myself, from the very beginning, to the acquisition of basic knowledge. 4) An obvious indication of my diligence was the fact that… 5) While at the stage of major courses, I could integrate the fragments of my insight from each lecture or book into a better understanding of the area

进一步阐述 )

写作模式（ 3 ） of... 6) The deeper I immersed myself into the ocean of…, in fact, the greater my

enthusiasm grew for… 7) So, I seized on every chance, including…, to… and to… 8) And meanwhile I never slackened my efforts in… 9) I always cling to the motto that any success in life rests with…

写作模式（ 4 ） 10) What I have done so far, however, is just

the first step on my way to being… 11) To my great delight, the Department of… of your University, high ranked in the world and rich with academic climate, can render me better able to… 12) Thus, I have every reason to believe that my… and your…, complete with my firm commitment to…, will turn my ambition into reality.