what is genetic drift what is natural selection how do these

what is genetic drift? what is natural selection? how do these process independently contributes to change in genetic composition of a population?

which process, natural selection or genetic drift, is more likely to affect a population in the short term? long term?

what is conservation genetic? why is maintainaning genetic diversity in a population is important?

Solution

The basic mechanism of evolution is Natural selection along with mutation ,migration and genetic drift.

Allele frequency refers to the random change in the genetic make up of a population over a period of time.Both natural selection and genetic drift play an important role in establishing a successful population in course of evolution.

Genetic drift : Genetic drift refers to the random change in the allele frequency in a population and plays an important role in evolution if the allel involved plays a significant role in propagation and reproduction of the organism.In such cases the establishment of the population depends solely on the presence or absence of that particular allele and is referred to as the pervasive effect.This sometime leads to the genetic bottle necks which reduces the genetic variations in the new or subsequent populations .It is more pronounced in smaller populations as seen in African cheetahs,they are believed to have undergone several botlle necks which is threatening their existence.

If the alleles have no impact on the survival or reproduction of the organism it may eventually become rare in population or may be lost if it is not passed on to the off springs.They loss of allele permanently leads to variation and small populations are more affected than the larger ones.

Natural selection refers to the selection of individuals by the nature that establish successfully and reproduce and thus establishing themselves in the nature.these organisms have have genotypes that can survive and establish the favoured allele in course of time and bring about variation. The classic example is the establishment of brown beetles over green beetles.