Question

What is genetic drift ? How it contributes to the formation of new species.

Answer 1

The genetic drift  is the process in which genetic composition of a population changes, it is the process of changing due to random events rather than natural. Changes in frequencies over time.  

Drift is basically observed in small populations and results in changes that need to be adaptive.

Answer 2

Genetic drift is a process in which allele frequencies within a population change by chance alone as a result of sampling error from generation. Genetic drift is a random process that can lead to large changes in populations over a short period of time.

Genetic drift occurs in small population where the variations (mutations) that occur are random, sudden and non directional. Genetic drift results in speciation. If few individuals of a species are isolated from the rest of population due to some catastrophic event then genetic drift will occur in these few members making them adaptable for the new environmental conditions. Few mutations will be fixed and others will be lost resulting in a new species.