Gene flow from an adaptively divergent source causes rescue through genetic and demographic factors in two wild populations of Trinidadian guppies

Genetic rescue, an increase in population growth owing to the infusion of new alleles, can aid the persistence of small populations, but its use as a management tool is limited by a lack of empirical data geared towards predicting effects of gene flow on local adaptation and demography. Experimental translocations provide an ideal opportunity to monitor the demographic consequences of gene flow. In this study we take advantage of two experimental introductions of Trinidadian guppies to test the effects of gene flow on downstream native populations. We individually marked guppies from the native populations to monitor population dynamics for 3 months before and 26 months after gene flow. We genotyped all individuals caught during the first 17 months at microsatellite loci to classify individuals by their genetic ancestry: native, immigrant, F1 hybrid, F2 hybrid, or backcross. Our study documents a combination of demographic and genetic rescue over multiple generations under fully natural...

遗传拯救（Genetic rescue）指通过引入新等位基因以提升种群增长速率，可助力小型种群存续，但其作为种群管理工具的应用受限于缺乏用于预测基因流对本地适应及种群统计学影响的实证数据。实验性易位为监测基因流的种群统计学后果提供了理想契机。本研究借助两次特立尼达孔雀鱼（Trinidadian guppies）的实验性引入，以检验基因流对下游本地种群的影响。我们对本地种群的个体进行标记，在基因流发生前的3个月以及基因流发生后的26个月内监测种群动态。我们对前17个月捕获的所有个体开展微卫星位点（microsatellite loci）基因分型，依据遗传血统对个体进行分类：本地个体、移民个体、F1杂种、F2杂种或回交个体。本研究记录了多代自然条件下遗传拯救与种群拯救的组合效应……