What are two ways that variation can be described?​

For a given population, there are three sources of variation: mutation, recombination, and immigration of genes.Variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation)

Explanation:

it will increase due to the time span