Differences are as follows: Mutation is resposible for adding genetic variation within a species.Gene flow results in exchange of genetic material between populations as a result of which speciation is prevented.Genetic drift occurs when there occurs isoltion of species from one another.Genetic drift results in loss of genetic variation.Natural selection contributes highest towards speciation It favours the survival of the fittest organism in a particular environment.Non random mating includes inbreeding that increases the chances of homozygosity in a population specially recessive homozygous. Genetic variability : Mutation :Increases genetic variability. Gene flow :Increases genetic variability. Genetic drift : Decreases genetic variability. Natural selection :Increases genetic variability. Non random mating :Decreases genetic variability. Genetic divergence: Mutation :Decreases genetic divergence. Gene flow :Decreases genetic divergence. Genetic drift : Increases genetic divergence. Natural selection :Decreases genetic divergence. Non random mating :Increases genetic divergence. Solution Differences are as follows: Mutation is resposible for adding genetic variation within a species.Gene flow results in exchange of genetic material between populations as a result of which speciation is prevented.Genetic drift occurs when there occurs isoltion of species from one another.Genetic drift results in loss of genetic variation.Natural selection contributes highest towards speciation It favours the survival of the fittest organism in a particular environment.Non random mating includes inbreeding that increases the chances of homozygosity in a population specially recessive homozygous. Genetic variability : Mutation :Increases genetic variability. Gene flow :Increases genetic variability. Genetic drift : Decreases genetic variability. Natural selection :Increases genetic variability. Non random mating :Decreases genetic variability. Genetic divergence: Mutation :Decreases genetic divergence. Gene flow :Decreases genetic divergence. Genetic drift : Increases genetic divergence. Natural selection :Decreases genetic divergence. Non random mating :Increases genetic divergence..