Genetic variation is a fact that a biological system – individual and population – is different over space. It is the base of the genetic variability of different biological systems in space.Genetic variation is based on the variation in alleles of genes in a gene pool.It occurs both within and among populations, supported by individual carriers of the variant genes. Genetic variation is brought about by random mutation, which is a permanent change in the chemical structure of a gene.utations are likely to be rare and most mutations are neutral or deleterious, but in some instances the new alleles can be favored by natural selection. Polyploidy is an example of chromosomal mutation. Polyploidy is a condition wherein organisms have three or more sets of genetic variation (3n or more).