Fitzpatrick Sarah W, Gerberich Jill C, Angeloni Lisa M, Bailey Larissa L, Broder Emily D, Torres-Dowdall Julian, Handelsman Corey A, López-Sepulcre Andrés, Reznick David N, Ghalambor Cameron K, Chris Funk W
Kellogg Biological Station Department of Integrative Biology Michigan State University Hickory Corners MI USA; Department of Biology Colorado State University Fort Collins CO USA.
Department of Biology Colorado State University Fort Collins CO USA.
Evol Appl. 2016 Feb 4;9(7):879-91. doi: 10.1111/eva.12356. eCollection 2016 Aug.
Genetic rescue, an increase in population growth owing to the infusion of new alleles, can aid the persistence of small populations. Its use as a management tool is limited by a lack of empirical data geared toward 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 conditions. Within both recipient populations, we found substantial and long-term increases in population size that could be attributed to high survival and recruitment caused by immigration and gene flow from the introduction sites. Our results suggest that low levels of gene flow, even from a divergent ecotype, can provide a substantial demographic boost to small populations, which may allow them to withstand environmental stochasticity.
基因拯救，即由于新等位基因的注入而导致种群增长增加，有助于小种群的存续。其作为一种管理工具的应用受到限制，因为缺乏用于预测基因流动对局部适应和种群统计学影响的实证数据。实验性迁移提供了一个监测基因流动对种群统计学后果的理想机会。在本研究中，我们利用两次特立尼达孔雀鱼的实验性引入来测试基因流动对下游本地种群的影响。我们对本地种群的孔雀鱼进行个体标记，以监测基因流动前3个月和基因流动后26个月的种群动态。我们对在最初17个月内捕获的所有个体进行微卫星位点基因分型，以根据其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。我们的研究记录了在完全自然条件下多代的种群统计学和基因拯救情况。在两个接受种群中，我们都发现种群规模有显著且长期的增加，这可归因于来自引入地点的移民和基因流动所导致的高存活率和繁殖率。我们的结果表明，即使是来自不同生态型的低水平基因流动，也可以为小种群提供显著的种群统计学提升，这可能使它们能够抵御环境随机性。
