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?

• genetic drift
• gene flow
• gene mutation
• genetic variation

Explanation:

The problem is about changes in gene pools due to an oil spill affecting populations. Genetic drift (specifically bottleneck effect) occurs when a population is drastically reduced, affecting gene pool frequencies. The oil spill likely caused a sharp population decline (bottleneck), so genetic drift is the mechanism. Gene flow involves migration, gene mutation is a random change (not directly from population reduction), and genetic variation is a general term, not a mechanism here.

Answer:

A. genetic drift