A group of well-separated islands in the Pacific Ocean has a population of hibiscus plants that produce either orange or white flowers. On one of the islands, most of the hibiscus plants were killed a few years ago by a volcanic lava flow. Why is there a greater percentage of orange hibiscus plants on this island than on the other islands? (SC.912.L.15.13)

Question

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1 point
Cross pollination across the islands without the lava flow caused the percentage of orange flowers to dramatically change on these islands over time.
The hibiscus plants on the island that had the lava flow suffered from a higher mutation rate than plants on to other islands, causing a difference in the populations.
The limited population size after the lava flow resulted in a limited gene pool, causing genetic drift in future generations of hibiscus plants on this island.
Orange flowering hibiscus plants were better adapted to survive lava flows, so white hibiscus were naturally selected out of the population of the island.

Answer 1

The correct answer is: The limited population size after the lava flow resulted in a limited gene pool, causing genetic drift in future generations of hibiscus plants on this island.

This situation describes the concept of genetic drift, which can occur in populations that experience a bottleneck effect (such as the severe reduction of the hibiscus plant population due to the lava flow). With fewer plants left, the genetic diversity of the population is reduced, and the traits represented in the surviving plants can shift over generations due to random chance rather than natural selection. This can lead to a higher percentage of orange hibiscus plants if they were more numerous in the surviving population.