Question

The population of the wolves living in a particular area has been greatly reduced due to a natural disaster. Which of the following best describes the impact of the disaster on the gene pool of their population?

• A. Gene flow
• B. Bottleneck effect
• C. Founder effect
• D. Gene migration

Answer 1

The correct option is B Bottleneck effect

Natural disasters like earthquakes, cyclones, floods may greatly reduce the size of the population by killing the individuals randomly and leaving behind a small, random assortment of survivors.
The gene pool of the small surviving population is often not a representative of the gene pool of the original population and some alleles may be missing entirely. This situation with reduced genetic variability is called the bottleneck effect. Bottleneck effect is an extreme example of genetic drift.

Genetic drift refers to the mechanism of evolution in which the gene frequencies of a population change due to a chance event. The effects of genetic drift are the strongest in small populations. There is a chance of certain traits being eliminated from a population due to genetic drift.

Another example of genetic drift is the founder effect.

When a few individuals become isolated from a larger population, this isolated group may establish a new colony, whose allele frequencies may differ from the original population; this is called the founder effect. The members of the isolated group are called as founders of the new population.

Gene flow/gene migration is the introduction of genes from one population to another. It results in the members of two different populations interbreeding and sharing alleles among themselves.