Population demographic history and evolutionary rescue: influence of a bottleneck event

Rapid environmental change presents a significant challenge to the persistence of natural populations. Rapid adaptation that restores positive growth rate, enabling populations in decline following severe environmental change to avoid extinction, is called evolutionary rescue. Numerous studies have shown evolutionary rescue can indeed prevent extinction. Here, we extend those results by considering the demographic history of populations. To evaluate how demographic history influences evolutionary rescue, we created 84 populations of red flour beetle, Tribolium castaneum, with three classes of demographic history: diverse populations that did not experience a bottleneck, and populations that experienced either an intermediate or a strong bottleneck. We subjected these populations to a new and challenging environment for six discrete generations and tracked extinction and population size. Populations that did not experience a bottleneck in their demographic history avoided extinction entirely, while more than 20% of populations that experienced an intermediate or strong bottleneck went extinct. Similarly, among the extant populations at the end of the experiment, adaptation increased fitness in the novel environment the most for populations that had not experienced a bottleneck in their history. Taken together, these results highlight the importance of considering the demographic history of populations to make useful and effective conservation decisions and management strategies for populations experiencing environmental change that pushes them towards extinction. ### Competing Interest Statement The authors have declared no competing interest.