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Danielle 26 - Homework Required Problems 26.1 26.2 26.3...

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Homework Required Problems: 26.1, 26.2, 26.3, 26.4, 26.6, 26.11, 26.13, 26.14 (skip part b), 26.17, 26.19, 26.20, 26.21, 26.23, 26.29. (There will be more problems from Ch. 9 later). Due March 26/28.
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Chapter 26. Population & Evolutionary Genetics Charles Darwin: Theory of evolution by natural selection, but no theory of heredity. Sewall Wright, R.A. Fisher, J.B.S. Haldane: Population genetics, and the New Evolutionary Synthesis. In populations, there are many different alleles of many different genes. We can see the variation! So, where do new alleles come from? -Rare mutations , occurring at random. -Mutations can be loss-of-function or gain-of-function.
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Allele Frequency Allele frequency – is the proportion of all copies of a gene in a population that are of a given allele type. Because each individual in a population has 2 copies of each gene, the total number of gene copies is two times the number of individuals in the population. Both homozygotes and heterozygotes contribute to the frequency of an allele, but homozygotes contribute twice the frequency of a particular allele, while heterozygotes contribute only once.
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Allele frequencies in populations: Counting alleles- AA homozygote Aa heterozygote aa homozygote 2 A alleles 2 a alleles 1 A and 1 a allele Sample population (10 individuals): # of A alleles = 2 (7AA) + 2 Aa = 16 # of a alleles = 2 (1aa) + 2Aa = 4 20 total alleles Aa AA AA AA AA aa AA Aa AA AA
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Let p = frequency of A in population Let q = frequency of a in population p = 16/20 = 0.8 = frequency of A gametes in population q= 4/20 = 0.2 = frequency of a gametes in population Note: p + q = 1 Therefore, p = 1-q and q = 1-p. So, if you know one you can calculate the other.
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Fig. 26.1 Expected frequencies of genotypes in large, random mating population p 2 + 2 pq + q 2 = 1 0.8 0.8 0.64 0.2 0.2 0.16 0.16 0.04 Expect: AA = p² = 0.64 Aa = 2pq = 0.32 Aa = q² = 0.04
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Will the allele frequencies change in the next generation?
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