Experimental and theoretical studies have highlighted the impact of gene flow on the probability of evolutionary rescue in structured habitats. Mathematical modelling and simulations of evolutionary rescue in spatially or otherwise structured populations showed that intermediate migration rates can often maximize the probability of rescue in gradually or abruptly deteriorating habitats. These theoretical results corroborate the positive effect of gene flow on evolutionary rescue that has been identified in experimental yeast populations. The observations that gene flow can facilitate adaptation are in seeming conflict with traditional population genetics results that show that gene flow usually hampers (local) adaptation. Identifying conditions for when gene flow facilitates survival chances of populations rather than reducing them remains a key unresolved theoretical question. We here present a simple analytically tractable model for evolutionary rescue in a two-deme model with gene flow. Our main result is a simple condition for when migration facilitates evolutionary rescue, as opposed as no migration. We further investigate the roles of asymmetries in gene flow and/or carrying capacities, and the effects of density regulation and local growth rates on evolutionary rescue. This article is protected by copyright. All rights reserved.

中文翻译：

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基因流动何时促进进化拯救？

实验和理论研究强调了基因流对结构化栖息地进化拯救概率的影响。空间或其他结构种群中进化救援的数学建模和模拟表明，中等迁移率通常可以最大限度地提高逐渐或突然恶化的栖息地的救援概率。这些理论结果证实了基因流动对实验酵母种群中已确定的进化拯救的积极影响。基因流动可以促进适应的观察结果似乎与传统的种群遗传学结果相冲突，后者表明基因流动通常会阻碍（局部）适应。确定基因流动何时促进种群生存机会而不是减少它们的条件仍然是一个关键的未解决的理论问题。我们在这里提出了一个简单的分析易处理模型，用于在具有基因流的二元模型中进行进化拯救。我们的主要结果是一个简单的条件，即迁移有利于进化拯救，而不是没有迁移。我们进一步研究了不对称在基因流动和/或携带能力中的作用，以及密度调节和局部增长率对进化拯救的影响。本文受版权保护。版权所有。与没有迁移相反。我们进一步研究了不对称在基因流动和/或携带能力中的作用，以及密度调节和局部增长率对进化拯救的影响。本文受版权保护。版权所有。与没有迁移相反。我们进一步研究了不对称在基因流动和/或携带能力中的作用，以及密度调节和局部增长率对进化拯救的影响。本文受版权保护。版权所有。