Wilson Benjamin A, Pennings Pleuni S, Petrov Dmitri A
Department of Biology, Stanford University, California 94305
Department of Biology, San Francisco State University, California 94132.
Genetics. 2017 Apr;205(4):1573-1586. doi: 10.1534/genetics.116.191478. Epub 2017 Feb 17.
Evolutionary rescue occurs when a population that is declining in size because of an environmental change is rescued from extinction by genetic adaptation. Evolutionary rescue is an important phenomenon at the intersection of ecology and population genetics, and the study of evolutionary rescue is critical to understanding processes ranging from species conservation to the evolution of drug and pesticide resistance. While most population-genetic models of evolutionary rescue focus on estimating the probability of rescue, we focus on whether one or more adaptive lineages contribute to evolutionary rescue. We find that when evolutionary rescue is likely, it is often driven by soft selective sweeps where multiple adaptive mutations spread through the population simultaneously. We give full analytic results for the probability of evolutionary rescue and the probability that evolutionary rescue occurs via soft selective sweeps. We expect that these results will find utility in understanding the genetic signatures associated with various evolutionary rescue scenarios in large populations, such as the evolution of drug resistance in viral, bacterial, or eukaryotic pathogens.
当一个因环境变化而数量减少的种群通过基因适应从灭绝中被拯救出来时，就会发生进化救援。进化救援是生态学和种群遗传学交叉领域的一个重要现象，对进化救援的研究对于理解从物种保护到药物和抗药性进化等一系列过程至关重要。虽然大多数进化救援的种群遗传模型侧重于估计救援的概率，但我们关注的是一个或多个适应性谱系是否对进化救援有贡献。我们发现，当进化救援很可能发生时，它通常是由软选择性清除驱动的，即多个适应性突变同时在种群中传播。我们给出了进化救援概率以及进化救援通过软选择性清除发生的概率的完整分析结果。我们预计这些结果将有助于理解与大种群中各种进化救援情景相关的遗传特征，例如病毒、细菌或真核病原体中的抗药性进化。
