Codes and data from: The effect of habitat choice on evolutionary rescue in subdivided populations

Evolutionary rescue is the process by which a population, in response to an environmental change, successfully avoids extinction through adaptation. In spatially structured environments, dispersal can affect the probability of rescue. Here, we model an environment consisting of patches that degrade one after another, and we investigate the probability of rescue by a mutant adapted to the degraded habitat. We focus on the effects of dispersal and of immigration biases. We find that the probability of evolutionary rescue can undergo up to three regions: (i) starting from low dispersal rates, it increases with dispersal; (ii) at intermediate dispersal rates, it decreases; (iii) finally, at large dispersal rates, the probability of rescue increases again with dispersal, except if mutants are too counter-selected in not-yet-degraded patches. The probability of rescue is generally highest when mutant and wild-type individuals preferentially immigrate into patches that have already undergone e...进化拯救（Evolutionary rescue）指种群应对环境变化时，通过适应性演化成功避免灭绝的过程。在空间结构化环境中，扩散（dispersal）会影响进化拯救的发生概率。本研究构建了依次发生退化的生境斑块（patches）模型，探究适应退化生境的突变型种群实现进化拯救的概率。本研究重点关注扩散以及迁入偏向对进化拯救概率的影响。我们发现，进化拯救概率可呈现至多三类区域特征：(i) 当扩散速率较低时，拯救概率随扩散提升而升高；(ii) 当扩散速率处于中等水平时，拯救概率随扩散提升而降低；(iii) 最终当扩散速率较高时，拯救概率会随扩散再次升高，除非突变型在未退化斑块中遭遇过强的负选择。通常而言，当突变型与野生型个体优先迁入已发生退化的生境斑块时，进化拯救概率达到最高