Hastings A
Genetics. 1985 Jan;109(1):215-28. doi: 10.1093/genetics/109.1.215.
The equilibrium structure of two-locus, two-allele models with very large selfing rates is found using perturbation techniques. For free recombination, r = 1/2, the following results hold. If the heterozygotes do not have at least an approximate 30% advantage in fitness relative to homozygotes, a stable equilibrium with all alleles present is possible only if all of the homozygote fitnesses differ at most by approximately the outcrossing rate, t, and all stable polymorphic equilibria have disequilibrium values, D, that are at most on the order of the outcrossing rate. Once the heterozygote fitnesses are above the threshold, there are stable equilibria possible with D near its maximum possible value. The results show that the observed disequilibria in highly selfed plant populations are not likely to result from selection leading to an equilibrium.
利用微扰技术找到了自交率非常高的两位点、两等位基因模型的平衡结构。对于自由重组，r = 1/2，有以下结果。如果杂合子相对于纯合子在适合度上没有至少约30%的优势，那么只有当所有纯合子适合度的差异至多约为异交率t，且所有稳定的多态平衡的不平衡值D至多约为异交率的量级时，所有等位基因都存在的稳定平衡才有可能。一旦杂合子适合度高于阈值，就有可能存在D接近其最大可能值的稳定平衡。结果表明，在高度自交的植物种群中观察到的不平衡不太可能是由导致平衡的选择引起的。
