Question

enry was studying two populations of the same species of lizards. One population lived on an island and the other lived on the mainland. Both populations were affected by a hurricane that hit the island and the mainland with equal force. A year later, Henry was testing the gene frequency and saw a decrease in genetic variation in the island species, but not in the mainland species. Which best describes a conclusion he might have reached?
Gene flow greatly affects small populations, but large populations can recover.
Genetic drift greatly affects small populations, but large populations can recover.
Gene flow greatly affects large populations, but small populations can recover.
Genetic drift greatly affects large populations, but small populations can recover.

Answer 1

Genetic drift greatly affects small populations, but large populations can recover.

Explanation: The hurricane caused a population bottleneck on the island (a small population), so random changes in allele frequencies (genetic drift) reduced genetic variation. The larger mainland population was buffered against drift, so it retained more variation.