lec_5_cond_13

So the change is substantial but slow δ p change in

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So the change is SUBSTANTIAL but SLOW Δ p = Change in p If evolution is so slow, then how did Δ CCR5 rise to a frequency of 9% in Northern Europe? Recent evidence indicates that another virus also uses the CCR5 receptor to enter cells the virus that causes smallpox, so 100’s of years of past adaptation to smallpox may have lead to the high frequency of Δ CCR5 in N. Europeans. We do not yet know for certain, but Very Important to do study questions from this lecture material p = 0.1 p ’ = .123 24 0.05 0.1 0.15 0.2 0.25 0.3 Row 1 0 1 0.1 0.2 0.3 Generation 0 1 2 3 4 5 W is the average ftness oF an allele in the gene pool and it also is the average ftness oF an individual in the population = average population ftness Frequency of Δ CCR5 ( p ) 4 years with 2-week life cycle But only W CCR5/ Δ CCR5 = W 12 = W* 12 / W* MAX = 1.8/2 = 0.9 W Δ CCR5/ Δ CCR5 = W = W* / W* MAX = 2/2 = 1.0 W CCR5/CCR5 = W 22 = W* 22 / W* MAX = 1.4/2 = 0.7 0.1 0.5 1.0 100 0 (2500 years)
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population one individual W = individual ftness = Darwinian ftness average W for all A 1 A 1 average W For all A 2 A 2 average W For all A 1 A 2 W * 11 W * 12 W * 22 divide by largest W * ij W 11 W 12 W 22 relative ftness oF each genotype ( W ij ) relative ftness oF each allele ( W i ) W 1 = p W 11 +qW 12 W 2 =qW 22 + p W 12 Note that each W i is a weighted average A2 p A1A2 Heterozygotes A2A2 Homozygotes q Homozygotes Heterozygotes A1 p q A1A1 A1A2 note: no subscripts note: 2 subscripts note: 1 subscript note: 2 subscripts Summary of Ftness measures 24B
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So the change is SUBSTANTIAL but SLOW Δ p Change in p If...

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