Unit 7 Book 4
Research into Population Genetics
Objectives:
Students will be able to
1. grasp the main idea of the text and the devices to develop the main idea;
2. be familiar with the useful words and phrases;
3. master the writing skill of supporting a statement by listing examples;
4. know the reading skill of scanning.
Tasks
1. Understanding the contents of the whole text;
2. Knowing the organization of the text and its main ideas;
3. Understanding some difficult sentences;
4. Remembering the newwords and expressions
6. Writing
- Background Information
1. 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.
2. Luca Cavalli-Sforza
Born in Genoa, Italy and educated at the University of Pavia, Italy, Cavalli-Sforza is a distinguished professor of genetics at the University of Stanford, California; he has specialized mainly in the genetics of human populations.
3. Columbus
Christopher Columbus, an Italian-born master navigator who sailed in the service of Spain, is commonly described as the discoverer of the New World –America. 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 Indies. It is as the result of Columbus’s “discovery” that New World became part of the European world.
4. 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.
5. Basques
The Basques are a people who live in a smallregion that straddles the border of Spain and France from the sea in the west into the Pyrenees in the east. 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.
- Answer the following questions.
1. What does The history and Geography of Human Genes conclude?
The ‘races” are remarkably alike under the skin and the variation among individuals is much greater than the differences among groups.
2. Where did the scientists find the information to draw a global family tree?
The information needed to draw that tree is found in human blood.
3. What two scientific aims does the book have?
It tells us the origins of populations and offers the latest raw material of the medical industry.
4. What is the ultimate aim of the book?
The ultimate aim is to weaken conventional notions of race that cause racial prejudice.
III. Text Analysis: Main Idea and Structure
1. What is the text mainly about?
This reading passage is concentrated on the latest research development in population genetics.
2. How is the text organized?
The passage can be broadly divided into 5 main parts: the theoretical significance of The History and Geography of Human Genes, the contribution of the book, the difficulties encountered in the process of conducting the research, the major contributions of the first genetic map and the conclusion (the social value of the search).
Part One (Para. 1) The author makes it clear that there is no scientific basis for theories pushing the genetic superiority of any one population over another according to the book, The History and Geography of Human Genes. It is a book containing a remarkable collection of more than 50 years of research in population genetics.
Part two (Para. 2) dealing with the exceptional work in the book: the creation of the genetic map of the world that traced the routes of early humans’ migration to find the closest thing we have to a global family tree.
Part three (Para. 3~~4) This part moves a bit backward to the work that is behind the scene. This can be taken as an inserted part, which tells us that the creative results came from the hard work over the years.
Par Four (Para. 5~~9) This is the major part of the essay, which lists 4 major contributions of the first genetic map of the world.
Part Five (Para. 10) The research mission is not just scientific but social as well. The study’s ultimate aim is to “weaken conventional notions of race” that cause racial prejudice.
IV. Expressions
1. to date: until now
eg. To date, research has focused on the most obvious feature of living things: cell multiplication.
Considerable evidence shows that, to date, those who have been successful through industrialization and urbanization have not been an independent, dynamic and progressive force in Latin America.
2. nothing less than: exactly the same as
eg. A co-educational school offers children nothing less than a true version of society in miniature.
His experience is nothing less than magical and I am moved to tears.
3. serve as: fulfill the purpose of (sth.)
eg. The judge said that the fine would serve as a warning to other motorists who drove without due care and attention.
In the absence of anything better the box would serve as a table.
4. be confined to: be restricted or kept within certain limits or time
eg. Disasters of this sort were confined to neither traditionally flooded land nor the winter months.
So far, fighting has been confined to the capital city.
5. as of/from: (used when a new rule, system, or situation will start) starting from
eg. As of the first of July, all back passengers must wear seat belts.
The new timetable will come into effect as of January 2008.
6. in effect: in fact
eg. What the management is saying, in effect, is that they are going to stop recruiting new staff.
In effect, the security of major professions was undermined for ever.
7. adapt to: change one’s behavior or sth. in order to deal more successfully with a new situation
eg. In deeper water, dwells an astonishing range of creatures adapting well to great pressure, extreme darkness, and a supply only available there.
Old buildings and streets, well cared for and adapted to today’s needs, vastly enhance the quality of life.
8. in combination with: together with; in conjunction with
eg. By using persuasion in combination with threats, she achieved great political success.
The artist uses photographs in combination with solid objects to produce this strange effect.
9. shed/throw light on: make a problem, etc. easier to understand
eg. But a better understanding of how it works could also shed light on other questions concerning the development of sensory nerve cells.
Scientists working in the Gobi desert have shed new light on the life of dinosaurs.
10. be descended from; have as an ancestor
eg. She always claimed her family was descended from the ancient Kings of Egypt.
The University of Edinburgh’s famous dropout, Charles Darwin, pointed out that human beings are descended fro, animals.
11. not just…but…as well: not only…but also
eg. The government radio not just reported the demonstration, but announced it in advance as well.
Some parents are not just concerned with safety but skeptical of the educational value of such strips as well.
V. Difficult sentences
1. It stands as the most extensive survey to date on how humans vary at the level of their genes. (Para. 1)
Meaning: The book marks itself out as a survey that has so far obtained the fullest information on human evaluation.
2. The book’s firm conclusion: once the genes for surface features such as skin color and height are discounted, the “races” are remarkably alike under the skin. (Para. 1)
Meaning: The book firmly concludes that if the genes for superficial characteristics such as skin color and height are disregarded, all human races are fundamentally alike.
3. In fact, there is no scientific basis for theories pushing the genetic superiority of any one population over another. (Para. 1)
Meaning: Actually, theories suggesting that one race of people is superior to another have no scientific basis.
4. Result: the closet thing we have to a global family tree. (Para. 2)
Meaning: As a result, we’ve got something extremely close to a global family tree—how the world populations are related to each other.
5. The information needed to draw that tree is found in human blood: various proteins that serve as markers to reveal a person’s genetic makeup. (Para. 3)
Meaning: It’s found that the different proteins in human blood provide the necessary information to draw that global family tree, for they can tell us about a person’s genetic structure.
6. And to ensure the populations were “pure”, the study was confined to groups that were in their present locations as of 1492, before the first major movements from Europe began – in effect, a genetic photo of the world when Columbus sailed for America. (Para. 3)
Meaning: And to make sure the survey participants were not mixed with outsiders, the study was limited to districts where people had been living since 1492 and were not affected by the first major movements from Europe due to Columbus’s discovery of America. In fact, what the scientists drew was a map of the world in 1492.
7. One of them jumps right off the book’s cover: a color map of the world’s genetic variation has Africa at one end of the range and Australia at the other. (Para. 5)
Meaning: One of the discoveries was right on the book’s cover, a color map of the world’s genetic change, showing that Australians are most distant from the Africans in genes.
8. But their genes tell a different story. (Para. 5)
Meaning: But the genes from Australians and Africans prove the wide assumption wrong.
9. The genetic map also shed light on the origins of populations that have long puzzled scientists. (Para. 7)
Meaning: The genetic maps also contribute to scientists’ new understanding of where some particular groups of people came from, which they’ve been working very hard to solve.
10. But their genes beg to differ. (Para. 7)
Meaning: But their genes tell a different story.
11. The study’s ultimate aim, he says, is to “weaken conventional notions of race” that cause racial prejudice. (Para. 10)
Meaning: He says that the study’s final and most important goal is to prove unconvincing the traditional views of race which only lead to unfair judgment.
VI. Reading Skill
Scanning
Broadly defined, to scan is to read quickly in order to locate or find the place in a piece of writing where a particular item of information is given and to take in that item of information. This kind of reading involves no reading in any detail of large sections of the piece of writing.
The steps involved in scanning are the following:
- Decide exactly what information you are looking for, and think about the form it may take.
- Decide where you need to look to find the information you want.
- Move your eyes as quickly as possible down the page until you find the information you need. Read it carefully.
- When you find what you need, do not read further.
VII. Writing
Listing is a very common writing technique. But some writers would list several items and then go into a bit details to support what has been argued by examples.
Topic; sticking to high moral standards is easier said than done.
Examples:
- a young British car manager, finish, the courses on business ethics, sell hundreds of cars
- the negotiation, without any real results, be at one’s wits end
- the answer, a popular novel, a check of $20,000
- this man examine, its contents, “Young man, I hear London is in its best in May?”
- quick-witted, “My company in London will be most honored to welcome your visit!”
- approve the deal, in London