Question

Write a note on "Genetic drift".

Answer 1

i. Any alteration in allele frequency in the natural population by pure chance is called genetic drift.
ii. For example, elimination of a particular allele from a population due to events like accidental death prior to mating of an organism.
iii. Genetic drift occurs when the sole possessor of a particular allele is removed from the population.
iv. It is also called Sewall Wright effect.

Answer 2

Answer:

(1) Genetic drift is random, directionless fluctuation that takes place in allele frequency.

(2) It occurs by pure chance, in small sized population.

(3) Genetic drift becomes an evolutional factor as it can change the gene frequency.

(4) Sewll wright has given this concept and hence it is also known as Sewall wright effect.

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

(6) Some time, a few individuals become isolated from the large population and they produce new population in new geographical area.

(7) Genetic drift is also called founders' effect because original drifted population becomes founders in the new area. E.g. Non-adaptive character of huge horns in Antelope is tixed due to genetic drift.