One of the original Amish colonies rose from a ship of colonists that came from Europe. The ship’s captain, who had polydactyly, a rare dominant trait, was one of the original colonists. Today, we see a much higher frequency of polydactyly in the Amish population. This is an example of:
a. natural selection
b. genetic drift
c. founder effect
d. b and c
The correct answer is d. b and c.
This scenario is an example of both genetic drift and the founder effect. The founder effect occurs when a new population is established by a small group of individuals, which can lead to a higher frequency of certain traits, such as polydactyly in this case. Genetic drift also plays a role as the allele frequencies in the small founding population may differ from those in the larger source population.