Gene selection of mendel’s rules

Abstract

Evolutionarily stable strategies are examined for genes affecting equal segregation and independent assortment. When a preferentially segregating allele incurs a cost of eliminating the other allele, it can invade a population only if some of the cost is reallocated to offspring containing the overrepresented allele. Different autosomal genes in one individual may have conflicting fitnesses whenever they do not invariably segregate into the same offspring. Evolutionarily stable strategies are examined for the rest of the genome to “cohabit” with two alleles, α1, and α2, which are adapted to different circumstances and thereby provide unique opportunities for their carriers. The ESS for genes which are not linked to such an ecologically maintained polymorphism is for α1, and α2 to segregate from α1, α2 heterozygotes in the ratio of their unique opportunities. Additional considerations usually operate to select positively for equal segregation, however. First, the combined effects of linked series of genes with distinct opportunities and linkage to invariably harmful alleles may cause the opportunities for heterozygous blocks of genes to average out towards equality. Second, genes which are linked with a and in linkage equilibrium with its alleles, and genes which cannot detect whether α1, or α2 offer more opportunities, have a risk-averting ESS when they cohabit equally with α1, and α2. Their cohabitation strategies generate selection for equal segregation and independent assortment. © 1984 The Genetical Society of Great Britain.