Answer:
0.09
Explanation:
<h3><u>Before selection</u></h3>
Total number in population = 1000
Genotype frequencies
Genotype frequency of BB = 500/1000 = 0.5
Genotype frequency of Bb = 250/1000 = 0.25
Genotype frequency of bb = 250/1000 = 0.25
Allele frequencies
Allele frequency of B = BB genotype frequency + half of the Bb genotype frequency = 0.5 + (0.25/2) = 0.625
Allele frequency of b = bb genotype frequency + half of the Bb genotype frequency = 0.25 + (0.25/2) = 0.375
<h3><u>After selection</u></h3>
We are told that after selection, the genotype frequency of bb is changed as they become 50% less fit. This means the frequency of bb individuals changes from 250 to 125 individuals (50% reduction).
Now the total number of individuals is 500 + 125 + 250 = 875.
Genotype frequencies
Genotype frequency of BB = 500/875 = 0.57
Genotype frequency of Bb = 250/875 = 0.29
Genotype frequency of bb = 125/875 = 0.14
Allele frequencies
Allele frequency of B = BB genotype frequency + half of the Bb genotype frequency = 0.57 + (0.29/2) = 0.715
Allele frequency of b = bb genotype frequency + half of the Bb genotype frequency = 0.14 + (0.29/2) = 0.285
<h3><u>Change in frequency of B after 1 generation</u></h3>
0.715 - 0.625 = 0.09
