Question

In a population of beetles, there are green and brown colorations that occur with equal frequency. After a forest fire, only 20 beetles remain. 18 of them are green and 2 of them are brown. What describes this change in frequencies?

A) Founder effect provided a new distribution of phenotype frequencies
B) Gene flow occurred, as the 20 beetles migrated from a distant location.
C) A population bottleneck occurred, altering the resulting allele frequencies.
D) Natural selection selected for phenotypes that blended with green leaves, which did not burn.

Answer 1

Answer: C

Explanation: A population bottleneck occurred, altering the resulting allele frequencies. Since a catastrophic fire affected the original population, many of the beetles were killed off. The resulting population that is left to reproduce has a different allele frequency. This is known as the bottleneck effect, and is a type of genetic drift. Allele frequency and phenotype frequency changes are random and are not due to selective pressures.

Answer 2

C. a population bottleneck occurred, altering the resulting allele frequencies

Step-by-step explanation:

A population bottleneck occurred, altering the resulting allele frequencies. Since a catastrophic fire affected the original population, many of the beetles were killed off. The resulting population that is left to reproduce has a different allele frequency. This is known as the bottleneck effect, and is a type of genetic drift. Allele frequency and phenotype frequency changes are random and are not due to selective pressures.