Question

question 22 of 25
which is an example of genetic drift?
a. disruptive selection divides a population into two new species.
b. selective breeding creates a new species of dog.
c. the allele frequency of a population changes due to a bottleneck effect.
d. a mutation spreads rapidly through a small population.

Explanation:

Genetic drift is a mechanism of evolution where allele frequencies in a population change due to random sampling (chance events). The bottleneck effect is a type of genetic drift. In a bottleneck, a large population is drastically reduced (e.g., due to a natural disaster), and the surviving population's allele frequencies may be different from the original population just by chance.

• Option A (disruptive selection) is a type of natural selection, not genetic drift.
• Option B (selective breeding) is an artificial process, not genetic drift.
• Option D (a mutation spreading) is related to mutation (a source of genetic variation) but not specifically genetic drift. Genetic drift is about random changes in allele frequencies, and the bottleneck effect (as in option C) is a classic example of genetic drift.

Answer:

C. The allele frequency of a population changes due to a bottleneck effect.