Data from: Antagonistic coevolution accelerates the evolution of reproductive isolation in Tribolium castaneum

The evolution of reproductive isolation among populations is often the result of selective forces. Among those, parasites exert strong selection on host populations and can thus also potentially drive reproductive isolation. This hypothesis has yet to be explicitly tested and, here, we set up a multigenerational coevolution experiment to explore this possibility. Five lines of Tribolium castaneum were allowed to coevolve with their natural parasite, Nosema whitei; five paired lines of identical origin were maintained in the absence of parasites. After 17 generations, we measured resistance within and reproductive isolation between all lines. Host lines from the coevolution treatment had considerable higher levels of resistance against N. whitei than their paired host lines which were maintained in the absence of parasites. Reproductive isolation was greater in the coevolved selection regime and correlated with phenotypic differentiation in parasite resistance between coevolved host lines. This suggests the presence of a selection-driven genetic correlation between offspring number and resistance. Our results show that parasites can be a driving force in the evolution of reproductive isolation, and thus potentially speciation.种群间生殖隔离（reproductive isolation）的演化通常是选择压力作用的结果。其中，寄生虫对宿主种群施加强烈的选择压力，因此也可能推动生殖隔离的演化。这一假说尚未得到明确验证，本研究因此设置多代协同进化实验以探究该可能性。我们将5组赤拟谷盗（Tribolium castaneum）种群与其天然寄生虫白氏微孢子虫（Nosema whitei）进行协同培养；另外5组起源完全一致的平行对照种群则在无寄生虫的环境中维持培养。经过17代培养后，我们对所有种群的种群内部抗性水平，以及各群体间的生殖隔离程度进行了测定。相较于无寄生虫环境中维持的平行对照宿主种群，经协同进化处理的宿主种群对白氏微孢子虫的抗性水平显著更高。协同进化选择处理组的生殖隔离程度更高，且与协同进化宿主种群间的寄生虫抗性表型分化显著相关。这表明子代数量与抗性之间存在由选择驱动的遗传相关。本研究结果证实，寄生虫可作为生殖隔离演化的驱动力，进而可能推动物种形成。