23_EvolutioninPopulations2a3_forupload

23_EvolutioninPopulations2a3_forupload - The Evolution of...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: The Evolution of Populations Can be extended to more than two alleles Two alleles - (p + q) 2 = 1 Three alleles - (p + q + r) 2 = 1 And X linked alleles Extensions of the Hardy-Weinberg Theorem Hardy Weinberg for sex-linked genes females males AA Aa aa p 2 2pq q 2 A a p q Problem: If the allele frequency of a recessive disease is 0.02, what proportion of the population will have the disease? X a X a X a So the disease frequency among females is 4 per 10,000, the same as with an autosomal gene. Fifty times more frequent in males than in females. Genot ypes A 1 A 1 A 1 A 2 A 1 A 3 A 2 A 2 A 2 A 3 A 3 A 3 Genot ype Frequencies P 11 P 12 P 13 P 22 P 23 P 33 p(A 1 ) = fr equency(A 1 ) = P 11 + 0.5 P 12 + 0 .5 P 13 p(A 2 ) = fr equency(A 2 ) = P 22 + 0.5 P 12 + 0 .5 P 23 p(A 3 ) = fr equency(A 3 ) = P 33 + 0.5 P 13 + 0 .5 P 23 p(A i ) = fr equency(A i ) = P ii + 0 .5 Sum k j,i j (P ij ) Hardy Weinberg equilibrium for m ultiple alleles: For a gene with m ultiple alleles, labeled A 1 , A 2 , ... ,A k , with frequencies p 1 , p 2 , ... , p k , the expected HWP for the homozygote A 1 A 1 is (p 1 ) 2 , and, for the heterozygote A 1 A 2 is 2p 1 p 2 , etc. The total frequency of expected homozygotes under HWP is F = p i 2 , and heterozygotes is H = 1 - F, termed the gene diversity index ....
View Full Document

Page1 / 23

23_EvolutioninPopulations2a3_forupload - The Evolution of...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online