BIOL 3300 Study Guide - Linkage Disequilibrium, Frequency-Dependent Selection, Haplotype
Document Summary
G6pd on x chromosome: 100"s of alleles with most of them decreasing the efficiency of the enzyme, varying effects. Allele 202a, possible malarial resistance: 18% in 3 african populations, 230 males, 9 alleles with 11 point mutations. The map shows the frequency of deficient males across the world: as can be seen the most amount of males deficient of g6pd are found in african countries. There is selection for individuals that are carriers, positive selection increases the frequency of the disease. 3 outcomes if the mutation is neutral: high frequency (dark blue line), low frequency (aqua line), and disappears (red line) Of recent positive selection the allele has had a high frequency and high linkage equilibrium. Extended haplotype homozygosity (ehh) is a measure of linkage with specific haplotypes. Positive selection increases the frequency of the allele. If ab is missing in a population, ab and ab will have to undergo recombination to eventually bring back ab.
