<P> Balancing selection refers to a number of selective processes by which multiple alleles (different versions of a gene) are actively maintained in the gene pool of a population at frequencies larger than expected from genetic drift alone . This can happen by various mechanisms, in particular, when the heterozygotes for the alleles under consideration have a higher fitness than the homozygote . In this way genetic polymorphism is conserved . </P> <P> Evidence for balancing selection can be found in the number of alleles in a population which are maintained above mutation rate frequencies . All modern research has shown that this significant genetic variation is ubiquitous in panmictic populations . </P>

Balancing selection is concerned with successful reproduction of