Figure 1. Two mechanisms of generation of mutants in diploids.

Mutation (red bar) in a gene (blue rectangle) occurring with frequency “m” will lead to a phenotypic change in diploid, either by a concomitant loss of heterozygosity (by recombination with frequency “r”) or deletion (“d”) or chromosome information loss/inactivation (“l”). The frequency of such events “f” should be the product of the frequencies of each independent event. Mutations can also occur independently in both alleles of a diploid but at different sites, and their frequency should be the square of “m”.