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DSST Anthropology as a Discipline 2

Your answer explanation boas was a leading opponent

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Your Answer: Explanation Boas was a leading opponent of the evolutionists, who he believed made too many assumptions based on too little data. Boas stressed the need to conduct anthropological research based only on facts and to distrust any expectations. Question 23 of 55 Genetic drift is another mechanism by which evolutionary changes may occur. It can be defined as the apparently random variation of certain gene frequencies under special conditions of small population size or of isolation or both. Also called the Sewall Wright effect and non-Darwinian evolution, it has been the subject of considerable controversy. Your Answer: Explanation Genetic drift is used to refer to various random processes that affect gene frequencies in small, relatively isolated populations. It is also known as the Sewall Wright effect. One variety of genetic drift occurs when a small population recently derived from a larger one expands in relative isolation. Called the founder effect, this process might occur, for example, if a family with ten children--all of whom exhibit a particular rare, but neutral, trait--moved to a tiny country hamlet. If all members of the family remained in the hamlet, married, and produced children who also stayed there and produced more children, and if the hamlet remained isolated from the outside world, the trait might become relatively common among residents of the area in a few generations. Question 24 of 55 The near absence of Blood Type B in the American Indian has been attributed to genetic drift . Your Answer: Explanation However, B-type blood reaches its highest frequency in some Mongoloid groups thought to be ancestral to the early inhabitants of the New World. Question 25 of 55 An allele is an alternate form of a gene at a given locus (location on a chromosome). Your Answer: Explanation Alternate forms of a gene are known as alleles. For example, given the gene for eye color, blue eyes, hazel eyes, and brown eyes are some of the alleles for that gene. A chromosome is an X-shaped collection of genes, and a locus is a specific position on that chromosome. Certain genes are always found on a certain chromosome (Humans have
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23 pairs of chromosomes) at a certain locus. Another example of alleles--the gene for ABO blood group has three alleles, A, B, and O. Question 26 of 55 Allele Frequency is the commonness of a particular allele in a given population, stated as a number, from 0 to 1, or as a percentage, from 0 to 100. Your Answer: Question 27 of 55 Genotypic Variations are caused by differences in number or structure of chromosomes or by differences in the genes carried by the chromosomes. Your Answer: Explanation Eye color, body form, and disease resistance are genotypic variations. As you recall, a person's genotype is the set of genes they carry. Typically differences in genotype are simply because one person has a unique set of alleles for his various traits given to him by his parents. Other possible differences, which are out of the ordinary, are having a different number or structure of chromosomes (instead of the ordinary 23 pairs of chromosomes).
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