间接选择与当地适应复合修饰符。草图当地存在的复合改性剂的发展如何适应(为了说明,R基因导致最大重组,和R基因指定0重组)。在迁移之前(步骤1),考虑两个栖息地与单倍体的个体。在左边,A和B等位基因是在两个不同位点的喜爱,右边的a和b等位基因是青睐。为了简化说明,我们认为有益的等位基因是固定的。迁移后的栖息地(步骤(2)和m = 1/2,移民所示红色),强大的LD选择的位点之间的生成:在每个栖息地有AB和AB但没有AB和AB单。然后随机交配和减数分裂发生(步骤3)。在每个栖息地,可以区分的分组人口全面重组等位基因和0 R重组等位基因(组四个人左右,职责)。在前者,LD之间选择的位点已经大大减少了(插图为零,事实上甚至全在每个减数分裂重组只有半LD),而在后者保持完好无损。重要的是,在这一步骤中r复合修饰符变得极端AB和AB单呈正相关。 Note also that in each habitat, variance in fitness is greater in the subpopulation with the r allele. Finally, selection occurs (favoring A and B on the left and a and b on the right, very strongly on the illustration) and takes the r allele along because of the linkage disequilibrium generated at the previous step (the overall frequency of r has risen from 1/2 to 2/3 in the illustration). Note that the case illustrated involves positive epistasis (only the extreme genotypes AB and ab survive, on the left and right, resp.). However, the r allele is favoured even if epistasis is zero, because selection is more efficient in subpopulations carrying the r allele since variance in fitness is greater in these subpopulations.