Why does genetic variance decrease within population and inc

Solution

Answer:

Genetic variation is the variation of genes and alleles both within and between populations. Genetic variation may result from mutation, migration, genetic drift and selection.

Within a population, genetic variation mainly results from mutation (permanent change in the DNA sequence), random mating and recombination during meiosis and fertilization in the population.

Genetic variation between populations increases as different populations are subjected to different environmental factors and selection pressures. So, genetic drift and natural selection are the two most important factors which results in variation between populations.

Genetic drift can lead to the formation of new alleles due to a sudden and abrupt change in the environmental conditions and can be different between populations. The alleles arising due to genetic drift is subjected to selection which results in its deletion from the population or may be the only allele present at a specific locus in the population.

Variation within populations may also occur due to spatial variation in the interacting animal communities.