In Drosophila melanogaster the phenotype curly wings is due

In Drosophila melanogaster, the phenotype \"curly wings\" is due to a dominant allele Cy that is lethal when homozygous. A population is established with an initial frequency of Cy equal to 0.168. Calculate the expected frequency in the next generation, assuming: a. that the relative fitness (w) of +/+ and CyJ + are both 1.0 b. that the relative fitness (w) of +/+ is 1.0 and Cy/+ is 0.5

Solution

(A)

- p = 0.168

w₁₁ = 1 and w₂₂ =1

w\' = p²w₁₁+ 2pqW_12+q²w₂₂

= 0.168²*1 + 2*0.168*0.168*1 + 0.168² *1

= 0.02 + 0.33 + 0.02

= 0.37

p\' = p(pw₁₁ + pw₂₂) / w\'

= 0.168(0.168*1 + 0.168*1) / 0.37

= 0.168(0.336) / 0.37

= 0.152

(B)

p = 0.168

w₁₁ = 1.0 and w₂₂ = 0.5

w\' = p²w₁₁+ 2pqW_{12 + q²}w₂₂

_{= 0.168}2 _{* 1 + 2*0.168*0.168*0.5 + 0.168² *0.5}

  _{= 0.02 + 0.02 + 0.01}

  _{= 0.05}

p\' = p(pw₁₁ + pw₂₂) / w\'

= 0.168(0.168*1 + 0.168*0.5) / 0.05

= 0.168(0.168 + 0.084) / 0.05

= 0.84