Question

henry 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.

Explanation:

Genetic drift is more impactful on small populations. Island populations are typically smaller than mainland ones. The hurricane likely caused a bottleneck effect (a form of genetic drift) in the small - sized island lizard population, reducing genetic variation. Mainland populations, being larger, are less affected by genetic drift and can maintain genetic variation. Gene flow (movement of genes between populations) is not relevant here as the question focuses on the effect of the hurricane within each population (island and mainland), not between them.

Answer:

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