A population of finches lives on an island some distance from the mainland, where another population of finches of the same species resides. In both populations, the size of the birds' beaks is influenced by two alleles at the beak locus, B and b. On the island, the frequency of the B allele is 0.9, and the frequency of the b allele is 0.1. On the mainland, both alleles are equally frequent (0.5).
a. If the genotypes at the beak locus have the following fitnesses on the island: wBB = 1, wBb = 0.95, wbb = 0.9, what is the change in the frequency of the B allele on the island in one generation due to natural selection?
b. What will be the change in the frequency of the B allele on the island in one generation as a combined result of migration and natural selection?
c. If the migration rate from the mainland to the island is 0.05 (meaning that 5% of individuals in the island population migrate in from the mainland every generation), what is the change in the frequency of the B allele in one generation due to migration? Assume there is no migration from the island back to the mainland.
A population of finches lives on an island some distance from the mainland, where another population of finches of the same species resides. In both populations, the size of the birds' beaks is influenced by two alleles at the beak locus, B and b. On the island, the frequency of the B allele is 0.9, and the frequency of the b allele is 0.1. On the mainland, both alleles are equally frequent (0.5).
a. If the genotypes at the beak locus have the following fitnesses on the island: wBB = 1, wBb = 0.95, wbb = 0.9, what is the change in the frequency of the B allele on the island in one generation due to natural selection?
b. What will be the change in the frequency of the B allele on the island in one generation as a combined result of migration and natural selection?
c. If the migration rate from the mainland to the island is 0.05 (meaning that 5% of individuals in the island population migrate in from the mainland every generation), what is the change in the frequency of the B allele in one generation due to migration? Assume there is no migration from the island back to the mainland.
