Although parasites are known to have various effects on their hosts, we know little about their role in the assembly of diversifying host populations. Using an experimental bacterium (Pseudomonas fluorescens SBW25)-bacteriophage (ϕ2) system, we show that earlier parasite arrival significantly reduced the repeatability of host diversification. Earlier parasite arrival amplified the priority effects associated with the stochastic emergence of novel SBW25 phenotypes, translating into greater historical contingency in SBW25 diversification. Our results highlight the important role of parasite-host interactions in driving host adaptive radiation.

中文翻译：

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寄生虫较早到达会降低宿主适应性辐射的可重复性。

尽管已知寄生虫会对宿主产生各种影响，但我们对其寄生虫在多样化宿主种群中的作用知之甚少。使用实验性细菌（荧光假单胞菌SBW25）-噬菌体（ϕ2）系统，我们显示较早的寄生虫到达显着降低了宿主多样化的可重复性。较早的寄生虫到达放大了与新的SBW25表型随机出现有关的优先效应，从而转化为SBW25多样化的更大历史偶然性。我们的结果突出了寄生虫-宿主相互作用在驱动宿主适应性辐射中的重要作用。