Question

In 1986, a nuclear power accident in Chernobyl, USSR (now Ukraine), led to high radiation levels for miles surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and evolutionary biologists have been studying rodent populations in the Chernobyl area ever since. Based on your understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations following the accident?
Mutation led to increased genetic variation.
Mutation caused genetic drift and decreased fitness.
Mutation caused the fixation of new alleles.
Mutations caused major changes in rodent physiology over time.

Answer 1

Answer:

The correct option is A. Mutation led to increased genetic variation.

Explanation:

Mutations are caused when there occurs a change in DNA segments of an organism. Mutations may be natural or due to environmental factors. If the changes are caused in the non-functional DNA then no possible phenotypic effects will be seen. But if mutations occur in the functional DNA, then changes in the genetic, as well as the phenotypic makeup will be seen. These changes will lead to an increase in the genetic variation of the species.

Answer 2

Answer:

Option A

Mutation led to increased genetic variation.

Explanation:

From the definition of mutation, it’s a sudden change in the deoxyribonucleic acid (DNA) which tends to alter the genetic message carried by that gene. Mutation is caused by a mutagen where for the case of Chernobyl, USSR (now Ukraine), the mutagen was radiation. Consequently, variations would occur in organisms that inhabited that area. However, it’s important to note that mutation can’t fix new alleles. Neither will mutation cause genetic drift and decreased fitness nor cause changes only in the physiology of an organism as depicted by the other choices. Finally, it’s important to recognize that mutations can increase genetic variation hence option A is the correct answer for this incidence.