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Study of the origins and distribution of human populations used to be based on archaeological and fossil evidence. A number of techniques developed since the 1950s, however, have placed the study of these subjects on a sounder and more objective footing. The best information on early population movements is
now being obtained from the “archaeology of the living body”, the clues to be found in genetic material.
Recent work on the problem of when people first entered the Americas is an example of the value of these new techniques. North-east Asia and Siberia have long been accepted as the launching ground for the first human colonisers of the New World. But was there one major wave of migration across the Bering
Strait into the Americas, or several? And when did this event, or events, take place? In recent years, new clues have come from research into genetics, including the distribution of genetic markers in modern Native Americans.
An important project, led by the biological anthropologist Robert Williams, focused on the variants (called GM allotypes) of one particular protein – immunoglobin G – found in the fluid portion of human blood. All proteins “drift”, or produce variants, over the generations, and members of an interbreeding
human population will share a set of such variants. Thus, by comparing the GM allotypes of two different populations (e.g. two Indian tribes), one can establish their genetic “distance”, which itself can be calibrated to give an indication of the length of time since these populations last interbred.
Williams and his colleagues sampled the blood of over 5,000 American Indians in western North America during a twenty-year period. They found that their GM allotypes could be divided into two groups, one of which also corresponded to the genetic typing of Central and South American Indians. Other tests showed that the Eskimo and Aleut formed a third group. From this evidence it was deduced that there had been three major waves of migration across the Bering Strait. The first, Paleo Indian, was more than 15,000 years ago was ancestral to all Central and South American Indians. The second wave, about 14,000-12,000 years ago, brought Na-Dene hunters, ancestors of the Navajo and Apache who migrated south from Canada about 600 to 7000 years ago. The third wave, perhaps 10,000 or 9,000 years ago, saw the migration from
North-east Asia of groups ancestral to the modern Eskimo and Aleut.
Question 21: Which of the following best serves as the title of the passage?
A. When the migration in America happened.
B. The relationship between population movements and genetics.
C. Distribution of human population in America.
D. The evidences of genetics in America.
Question 22: Where did scientists find out the information on early population movements?
A. From human distribution
B. From archeological documents of living creatures.
C. From fossil evidence
D. From genetic material of the living body
Question 23: According to Robert Williams, Gm allotypes of immunoglobin G in human blood show one person belongs to an interbreeding human population_______?
A. Because of a similar set of variants.
B. Because the protein, immunoglobin G, produces variants.
C. When a population establishes genetic distance.
D. When the populations interbred.
Question 24: The word “indication” paragraph 3 is closest in meaning to_________?
A. discussion B. statement C. suggestion D. idea
Question 25: When did Robert William start to do research on blood samples of American Indians?
A. 9,000 years ago B. 600 years ago C. 5,000 years ago D. 20 years ago
Question 26: Which of the following is NOT mentioned in paragraph 4?
A. Williams had another research in Arizona.
B. Williams found out major waves of immigration.
C. Williams showed the milestones of each wave.
D. Williams studied the ancestors of Eskimo and Aleut.
Question 27: The word “their” paragraph 4 refers to________?
A. William and his colleagues B. American Indians
C. Blood samples D. Two populations
Question 21: Which of the following best serves as the title of the passage?
A. When the migration in America happened.
B. The relationship between population movements and genetics.
C. Distribution of human population in America.
D. The evidences of genetics in America.
Question 22: Where did scientists find out the information on early population movements?
A. From human distribution
B. From archeological documents of living creatures.
C. From fossil evidence
D. From genetic material of the living body
Question 23: According to Robert Williams, Gm allotypes of immunoglobin G in human blood show one person belongs to an interbreeding human population_______?
A. Because of a similar set of variants.
B. Because the protein, immunoglobin G, produces variants.
C. When a population establishes genetic distance.
D. When the populations interbred.
Question 24: The word “indication” paragraph 3 is closest in meaning to_________?
A. discussion B. statement C. suggestion D. idea
Question 25: When did Robert William start to do research on blood samples of American Indians?
A. 9,000 years ago B. 600 years ago C. 5,000 years ago D. 20 years ago
Question 26: Which of the following is NOT mentioned in paragraph 4?
A. Williams had another research in Arizona.
B. Williams found out major waves of immigration.
C. Williams showed the milestones of each wave.
D. Williams studied the ancestors of Eskimo and Aleut.
Question 27: The word “their” paragraph 4 refers to________?
A. William and his colleagues B. American Indians
C. Blood samples D. Two populations