Question

changes in the gene pool can occur due to various mechanisms. in 1989, a large oil spill occurred in prince william sound, alaska, when the exxon valdez oil tanker ran aground. approximately 11 million gallons of oil were spilled and spread 1,300 miles along the alaskan coastline. the damage from the oil spill affected thousands of animals in the area, including killer whales, harbor seals, sea otters, fish, and sea birds. which mechanism most likely affected the gene pools of the organism populations in the areas around the oil spill?
o genetic drift
o gene flow
o gene mutation
o genetic variation

Explanation:

Genetic drift is a mechanism of evolution where allele frequencies in a population change due to random sampling of organisms. In the case of the oil spill, a large number of organisms (a non - random sample in terms of normal population dynamics) were killed. This sudden reduction in population size (a population bottleneck, which is a type of genetic drift) can lead to changes in the gene pool. Gene flow is the transfer of genetic material between populations. There is no indication of movement of organisms in or out of the affected area. Gene mutation is a change in the DNA sequence of a gene, and there is no mention of a mutagenic effect of the oil (other than killing) that would cause specific gene mutations. Genetic variation is a general term for the presence of variation in the genetic makeup of a population, not a mechanism of change in the gene pool like the ones listed.

Answer:

genetic drift