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

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 explanation for the greater percentage of orange hibiscus plants on the island that experienced a volcanic lava flow 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.

When the lava flow eliminated a large portion of the hibiscus population, the surviving plants became a small, isolated gene pool. This limited genetic diversity can lead to genetic drift, where certain traits (like flower color) may become more pronounced in the remaining population simply due to chance rather than natural selection. If, by chance, the surviving plants were predominantly orange-flowered, that trait would become more common in the future generations on that island.