Explain5 marksStandard
A mainland population of a bird species has two alleles for feather colour: B (brown) and b (white). The frequency of the B allele is 0.7 and the frequency of the b allele is 0.3. A small group of 10 birds from this mainland population is carried by a storm to a remote island. On the island, the birds find abundant food and no predators. The allele frequencies in this small group happen to be: B = 0.9 and b = 0.1.
Explain how the founder effect causes the allele frequencies in the island population to differ from the mainland population.