Rare extreme “black swan” disturbances can impact ecosystems in many ways, such as destroying habitats, depleting resources, and causing high mortality. In rivers, for instance, exceptional floods that occur infrequently (e.g., so‐called “50‐year floods”) can strongly impact the abundance of fishes and other aquatic organisms. Beyond such ecological effects, these floods could also impact intraspecific diversity by elevating genetic drift or dispersal and by imposing strong selection, which could then influence the population's ability to recover from disturbance. And yet, natural systems might be resistant (show little change) or resilient (show rapid recovery) even to rare extreme events – perhaps as a result of selection due to past events. We considered these possibilities in two rivers where native guppies experienced two extreme floods – one in 2005 and another in 2016. For each river, we selected four sites and used archived “historical” samples to compare levels of genetic and phenotypic diversity before vs. after floods. Genetic diversity was represented by 33 neutral microsatellite markers, and phenotypic diversity was represented by body length and male melanic (black) colour. We found that genetic diversity and population structure was mostly “resistant” to even these extreme floods; whereas the larger impacts on phenotypic diversity were short‐lived, suggesting additional “resilience”. We discuss the determinants of these two outcomes for guppies facing floods, and then consider the general implications for the resistance and resilience of intraspecific variation to black swan disturbances.

中文翻译：

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遗传和表型多样性对“黑天鹅”洪水事件的抵抗力和复原力：孔雀鱼历史样本的回顾性分析

罕见的极端“黑天鹅”干扰会以多种方式影响生态系统，例如破坏栖息地，消耗资源并造成高死亡率。例如，在河流中，很少发生的罕见洪水（例如所谓的“ 50年洪水”）会严重影响鱼类和其他水生生物的数量。除了这种生态影响之外，这些洪水还可能通过提高遗传漂移或扩散以及强加选择来影响物种内的多样性，进而影响种群从干扰中恢复的能力。然而，即使对于罕见的极端事件，自然系统也可能具有抵抗力（几乎没有变化）或有弹性（表明快速恢复）–可能是由于过去事件导致的选择。我们考虑了两条河流中本地孔雀鱼经历两次极端洪水的可能性-一次是在2005年，另一次是在2016年。对于每条河流，我们选择了四个地点，并使用存档的“历史”样本比较了之前和之后的遗传和表型多样性水平洪水。遗传多样性由33个中性微卫星标记代表，表型多样性由体长和雄性黑色（黑色）颜色代表。我们发现，即使在这些极端洪灾中，遗传多样性和种群结构也大多“抵抗”了我们。而对表型多样性的更大影响是短暂的，这表明了额外的“复原力”。我们讨论了面对洪水的孔雀鱼这两个结果的决定因素，