Question

Assume that there are 12 mice living on an island. Now, there is a flood because of which most of the mice population is wiped out, and only 4 mice survive. This results in a sharp lowering of the population's gene pool. Such a phenomenon is known as

• A. Gene flow
• B. Genetic drift
• C. Founder effect
• D. Bottleneck effect

Answer 1

The correct option is D Bottleneck effect

Gene flow is the transfer of genes or alleles from one population to another. Genetic drift refers to the change in the frequency of alleles in a population due to chance events. It could either happen due to founder effect or bottleneck effect. Founder effect is an ecological phenomenon that occurs when a few members of an original population colonise a new location away from the old location. Bottleneck effect is an ecological phenomenon in which there occurs a sharp lowering of a population's gene pool, mostly because of natural disasters. In the situation described here, on the island occupied by the population of mice, the flood occurred, resulting in a drastic decline in the population's gene pool. Therefore it is an example of bottleneck effect.