CAREER: The Influence of Gene Flow on Inbreeding Depression and Local Adaptation: Replicated Experiments in Isolated Wild Populations

大多数物种是由在某种程度上交换基因的多个种群组成的。这种遗传物质的交换对种群的持久性有积极的还是消极的影响，这是进化生物学中一个长期但仍未解决的问题。这一问题在栖息地碎片化的背景下具有保护意义。栖息地碎片化是许多物种自然种群的主要威胁，因为它阻碍了遗传交流和隔离种群。与世隔绝的小种群经常遭受遗传多样性丧失、近亲交配增加以及适应新环境条件的能力下降的痛苦。该项目的目标是通过实验在孤立的天然鲑鱼种群中诱导基因交换，以此作为了解基因流影响的窗口。这项工作将有助于解决进化生物学中长期存在的问题，并将有助于为保护和管理提供信息。人们对利用动物或植物的战略性转移来帮助拯救与世隔绝的种群免于灭绝有很大兴趣。然而，对基因交换可能产生的负面后果的担忧限制了这种管理方法的应用。这项研究的教育部分将向管理专业人员和蒙大拿州的所有教育级别的学生传授遗传原理在保护中的应用。该项目将测试基因流入美国东部和西部孤立鲑鱼种群的实验脉冲的成本和收益。在第一个研究系统中，从远交移民到近亲交配受体群体的实验基因流动被预测通过减缓近亲交配而产生积极的适应度效应。在第二个研究系统中，从近亲交配的移民到近亲交配的受体种群的实验性基因流动被预测为对健康的影响可以忽略不计，因为近亲交配的移民不会掩盖近交受体种群中的有害等位基因。这项工作将在两个研究系统中检查在有机体和基因组水平上基因流动可能产生的负面影响。该项目还将使用创新的教育方法，增加现有野生动物专业人员、目前在美国领先的野生动物生物学项目中注册为本科生的未来专业人员以及蒙大拿州农村中学生对遗传原理的了解。

Most species are comprised of multiple populations that exchange genes to some extent. Whether this exchange of genetic material has positive or negative effects on population persistence is a longstanding but still unresolved issue in evolutionary biology. This issue has conservation relevance in the context of habitat fragmentation. Habitat fragmentation is a major threat to natural populations of many species because it prevents genetic exchange and isolates populations. Small and isolated populations often suffer from a loss of genetic diversity, increased inbreeding, and a reduced ability to adapt to new environmental conditions. The goal of this project is to experimentally induce genetic exchange in isolated natural trout populations as a window into understanding the effects of gene flow. This work will help resolve longstanding questions in evolutionary biology and will help to inform conservation and management. There is substantial interest in using strategic translocations of animals or plants to help save isolated populations from extinction. However, concerns about the possible negative consequences of genetic exchange have limited the application of this management approach. The educational components of this research will teach management professionals and Montana students, at all educational levels, about the application of genetic principles to conservation. This project will test the costs and benefits of experimental pulses of gene flow into isolated populations of trout in both the eastern and western United States. In the first study system, experimental gene flow from outbred immigrants into inbred recipient populations is predicted to have a positive fitness effect through the alleviation of inbreeding. In the second study system, experimental gene flow from inbred immigrants into inbred recipient populations is predicted to have negligible fitness effects because inbred immigrants will not mask deleterious alleles in inbred recipient populations. The work will examine the possible negative effects of gene flow at organismal and genome levels in both study systems. The project will also use innovative educational approaches to increase knowledge of genetic principles in current wildlife professionals, future professionals currently enrolled as undergraduates in the nation's leading Wildlife Biology program, and rural Montana middle school children.