Question

Short answer question.

Write a note on Genetic drift.

Answer 1

1. Any alternation in allele frequency in the natural population by chance, is called genetic drift. e.g. Elimination of a particular allele from a population due to events like accidental death prior to mating of an organism.

2. The concept of genetic drift was first given by Sewall Wright and is hence also called the Sewall Wright effect.

3. Genetic drifts are random or directionless.

4. The effect of genetic drift is more significant in small population than in large populations.

5. Due to genetic drift, some alleles of a population are lost or reduced by chance, and some others may be increased.

6. Sometimes, a few individuals become isolated from the large population, and they produce a new population in a new geographical area. The allele frequency of the new population becomes different. The original drifted population (i.e. colonizing ancestor/ pioneer) becomes ‘founders’ and the effect is called the founder effect.

7. A bottleneck effect is seen when much of a population is killed due to a natural disaster and only a few remaining individuals are left to begin a new population.