Data from: Inter-locus sexually antagonistic coevolution creates indirect selection for increased recombination

The ubiquity of recombination in nature is a paradox because it breaks up combinations of alleles favored by natural selection. Theoretical work has shown that antagonistic coevolution between hosts and parasites can result in rapid fluctuations in epistasis, which can create a short-term advantage to recombination. Here we show that another kind of antagonistic coevolution, inter-locus sexually antagonistic coevolution (SAC), can also create indirect selection for modifiers that increase the rate of recombination, and that it can lead to very high levels of recombination at equilibrium. Recombination is favored because inter-locus SAC creates heterogeneity in the strength and direction of selection, both within and between generations, which maintains an excess of disadvantageous haplotypes in the population. This result is similar to and consistent with dynamics of fluctuating epistasis produced in models of host-parasite coevolution. However, the conditions under which inter-locus SAC provides an advantage to recombination are more permissive.

自然界中重组现象的普遍存在性看似是一个悖论——因为它会打破自然选择所青睐的等位基因组合。已有理论研究表明，宿主与寄生虫之间的拮抗协同进化（antagonistic coevolution）可导致上位性（epistasis）快速波动，从而为重组带来短期选择优势。本研究表明，另一类拮抗协同进化，即基因座间性拮抗协同进化（inter-locus sexually antagonistic coevolution，SAC），同样可对提升重组速率的修饰因子产生间接选择作用，并可使种群在平衡状态下达到极高的重组水平。重组之所以受到青睐，是因为基因座间性拮抗协同进化会在世代内部与世代之间造成选择强度与选择方向的异质性，进而使种群中维持着过量的有害单倍型（haplotype）。这一结果与宿主-寄生虫协同进化模型中产生的上位性波动动力学特征相似且一致。但基因座间性拮抗协同进化为重组带来选择优势的条件更为宽松。