NEET BIOLOGY

Detailed explanation-1: -The founder effect is a severe case of population bottleneck and happens when a few individuals migrate out of a population to establish a new subpopulation. Random genetic drift accompanies such founder effect, to severely reduce the genetic variation that exists in the original population.

Detailed explanation-2: -Demographic bottlenecks generally reduce genetic diversity through more intense genetic drift, but their net effect may vary along the genome due to the random nature of genetic drift and to local effects of recombination, mutation, and selection.

Detailed explanation-3: -Once it begins, genetic drift will continue until the involved allele is either lost by a population or is the only allele present at a particular gene locus within a population. Both possibilities decrease the genetic diversity of a population.

Detailed explanation-4: -Genetic drift can have major effects when a population is sharply reduced in size by a natural disaster (bottleneck effect) or when a small group splits off from the main population to found a colony (founder effect).

Detailed explanation-5: -Populations generate genetic variation over time, which can be specifically reduced by selection or stochastically reduced by genetic bottlenecks. After a bottleneck, a limited number of randomly selected individuals create a founding population, resulting in genetic drift.