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?

Question

Quizplus · Accepted Answer

The high radiation levels caused by the nuclear accident likely increased the mutation rate in rodent populations. As a result, the increased genetic variation may have allowed some individuals to survive and reproduce in the new environment. This can lead to "adaptive evolution", which is the process by which populations evolve in response to environmental changes. While mutations may cause changes in rodent physiology over time, it is more likely that the increased genetic variation led to increased abilities to adapt to the environment. Additionally, genetic drift and decreased fitness are possible outcomes of mutations, but there is no evidence to suggest that this occurred in the Chernobyl rodent populations. Finally, it is unlikely that new alleles became fixed in the population as a result of the accident since genetic variation would have been increased.

In 1986, a Nuclear Power Accident in Chernobyl, USSR (Now