Answer:
The genotype, A1A2, will become fixed in the population.
Explanation:
Balancing Selection is a process that can be achieved in many ways, most of the times, when the heterozygotes for the alleles being analyzed have a better fitness than the homozygote. More importantly, bàlancing selection explain the different ways of selective processes by which various alleles, that is, different types of a gene are constantly maintained in the gene pool of a population at rate higher than the usual from genetic drift alone.
Using calculation to understand better
The Hardy-Weinberg principle can be used in this case to calculate genotype frequencies from allele frequences.
From assumption A1 and A2 are two alleles at the same locus,
p is the frequency of allele A 0.5 =< p =< 1
q is the frequency of allele A2 0.5 =< q =< 1,
and p + q = 1
where the distribution of allele frequencies is the same in men and women, i.e.:
Male(p,q) female (p,q)
if they procreate : (p + q)2 = p2 + 2pq + q2 = 1
where:
p2 = frequency of the A1 A1 genotype <-- HOMOZYGOTE
2pq = frequency of the A1 A2 genotype <-- HETEROZYGOTE
q2 = frequency of the A2 A2 genotyp <-- HOMOZYGOTE
these frequencies remain constant in successive generations.
The Allele frequency in the 10th generation
A1A1 A1A2 A2A2
1st Generation p2 2pq q2
10th Generation F(A1) = W+ Y/2 = p2 +1/2 (2pq) = p (p+q) = p
F(A2) = Z + H/2 = q2 +1/2 (2pq) = q (p+q) = q
The result is that, there is no change in allele frequencies:
in the 1st/current generation, we have p and q
in the 10th generation, we have p and q
Note: The frequencies of genotypes F(G) be called W, Y, and Z
with 0 =< [D,H,R] = < 1
and D + H + R = 1
The frequencies of alleles F(A) be called p, and q
with 0 =< [p,q] =< 1
and p+q = 1
The Hardy–Weinberg principle, otherwise known as the Hardy–Weinberg equilibrium, model, theorem, or law, "states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences."
