A large population of mosquitos with a good fit to HW has al

A large population of mosquitos with a good fit to H-W has alleles A1 and A2 with p = 0.1 and q = 0.9. A changed environment then results in selection and a violation of H-W assumptions. The following survival fitness values (w) of the genotypes are observed: w(A1A1) = 0.85; w(A1A2) = 1; w(A2A2) = 0.75. Determine the allele frequencies and genotype frequencies in the offspring population after the first generation of selection. Assume equal reproductive success for all survivors.

Solution

p = 0.1 q = 0.9 then p2+2pq+q2 =1 (0.1)2+ 2 (0.1)(0.9) + (0.9)2 =1 0.01 +0.18+0.81 =1 genotypic frequency of A1A1 = 0.01 genotypic frequency of A1A2 = 0.18 genotypic frequency of A2A2 = 0.81 survival fitness..........w(A1A1) = 0.85; w(A1A2) = 1; w(A2A2) = 0.75 mean fitness..............(0.85x0.85x0.01)2+2( 0.85 x 0.75x0.18)+(0.75x 0.75x0.81) ......................................0.0072+ 0.2295+ 0.4556= 0.69 new frequency of A1A1 =(0.85x0.85x0.01)/0.69 = 0.01 new frequency of A1A2 = (0.85 x 0.75x0.18)/0.69 = 0.33 new frequency of A2A2 =(0.75x 0.75x0.81)/0.69 = 0.66