Question

2. (10pts) In an area on the East coast of Africa with minimal medical facilities the fitness of HbA/HbA = 0.3, of HbA / Hbs = 1.0, and of Hbs/ HbS is 0.2. The frequencies of the three genotypes in this population in the current generation before selection are: HbA/HbA HbA/Hbs. HbS/Hbs. 0.71 0.22 0.07 a. What are the frequencies of the A and S alleles in this population? b. What will be the frequencies of the alleles in this population after selection? c. What will be the genotype frequencies (before selection) in the next generation?

Answer 1

a. In case of this,the frequency of the alleles has to find out using the before selection criteria. Therefore the frequency of the allele A will be equal to2*.71+0.22/3 = 0.546

Frequency of allele S =(0.14+0.22)/3 = 0.12

b. Considering the situation of the after selection the condition will be

Frequency of allele A = 2*0.3+1.0/3=0.6+1.0/3 = 0.533

Frequency of allele S = 2*0.2+1.0/3= 0.4+1/3 = 0.466

C. The frequency criteria after the selection will be similar to the condition which has been mentioned in the answer b for the next generation and the frequency ratio will match accordingly.