Data from: Hill-Robertson interference maintained by red queen dynamics favours the evolution of sex

Although it is well established theoretically that selective interference among mutations (Hill-Robertson interference) favours meiotic recombination, genome-wide mean rates of mutation and strengths of selection appear too low to support this as the mechanism favouring recombination in nature. A possible solution to this discrepancy between theory and observation is that selection is at least intermittently very strong due to the antagonistic coevolution between a host and its parasites. The Red Queen theory posits that such coevolution generates fitness epistasis among loci, which generates negative linkage disequilibrium among beneficial mutations, which in turn favours recombination. This theory has received only limited support. However, Red Queen dynamics without epistasis may provide the ecological conditions that maintain strong and frequent selective interference in finite populations that indirectly selects for recombination. This hypothesis is developed here through the simulation of Red Queen dynamics. This approach required the development of a method to calculate the exact frequencies of multi-locus haplotypes after recombination. Simulations show that recombination is favoured by the moderately weak selection of many loci involved in the interaction between a host and its parasites, which results in substitution rates that are compatible with empirical estimates. The model also reproduces the previously reported rapid increase in the rate of outcrossing in Caenorhabditis elegans coevolving with a bacterial pathogen.尽管理论研究已充分证实，突变间的选择干扰（Hill-Robertson interference）会促进减数分裂重组，但全基因组范围内的平均突变率与选择强度似乎过低，无法支撑该理论作为自然界中重组偏好性的驱动机制。针对这一理论与观测结果间的矛盾，一个可能的解决方案是：宿主与其寄生虫之间的拮抗协同进化，会使选择强度至少在间歇性时段内处于极高水平。红皇后理论（Red Queen theory）提出，这类协同进化会在不同基因座间产生适合度上位性（fitness epistasis），进而在有益突变间形成负连锁不平衡（negative linkage disequilibrium），最终推动重组的发生。但该理论仅获得了有限的实证支持。然而，不具备上位性的红皇后动态（Red Queen dynamics），或许能够提供维持有限种群内高强度、高频选择干扰的生态条件，进而间接推动重组的演化偏好。本文通过模拟红皇后动态，对这一假说展开了研究。该研究路径需要开发一种可精准计算重组后多基因座单倍型频率的方法。模拟结果显示，宿主与寄生虫互作所涉及的众多基因座所受的中等强度弱选择，会倾向于促进重组，由此产生的替代速率与实证估算结果相符。该模型还重现了此前报道的、与细菌病原体协同进化的秀丽隐杆线虫（Caenorhabditis elegans）的异交率快速上升现象。