The maintenance of the genetic variability of polygenic characters by heterozygous advantage.
D000704:Analysis of Variance; D014644:Genetic Variation; D006579:Heterozygote; D006720:Homozygote; D006823:Hybrid Vigor; D006824:Hybridization, Genetic; D008433:Mathematics; D009154:Mutation; D012641:Selection, Genetic