Data from: Coevolutionary dynamics of polyandry and sex-linked meiotic drive

Segregation distorters located on sex chromosomes are predicted to sweep to fixation and cause extinction via a shortage of one sex, but in nature they are often found at low, stable frequencies. One potential resolution to this long-standing puzzle involves female multiple mating (polyandry). Because many meiotic drivers severely reduce the sperm competitive ability of their male carriers, females are predicted to evolve more frequent polyandry and thereby promote sperm competition when a meiotic driver invades. Consequently, the driving chromosome's relative fitness should decline, halting or reversing its spread. We used formal modeling to show that this initially appealing hypothesis cannot resolve the puzzle alone: other selective pressures (e.g. low fitness of drive homozygotes) are required to establish a stable meiotic drive polymorphism. However, polyandry and meiotic drive can strongly affect one another's frequency, and polyandrous populations may be resistant to the invasion of rare drive mutants.位于性染色体上的分离驱动因子（Segregation distorters）理论上会快速扩散并达到固定状态，并因引发性比失衡而导致种群灭绝，但在自然环境中，这类因子往往仅以较低的频率稳定存在。针对这一长期存在的演化谜题，一个潜在的解决方案涉及雌性多次交配行为（polyandry）。由于多数减数分裂驱动因子（meiotic drive）会显著降低其携带雄性的精子竞争能力，理论上雌性会演化出更频繁的一妻多夫行为，从而在减数分裂驱动因子入侵种群时促进精子竞争。如此一来，驱动染色体的相对适合度（relative fitness）便会下降，进而阻止甚至逆转其扩散进程。我们通过严谨的建模分析表明，这一乍看颇具吸引力的假说无法单独解决该谜题：还需要其他选择压力（例如驱动纯合子的低适合度）才能建立稳定的减数分裂驱动多态性（polymorphism）。不过，一妻多夫行为与减数分裂驱动可对彼此的频率产生强烈影响，且实行一妻多夫的种群或可抵御稀有驱动突变体的入侵。