Evolutionary and ecological genetics of fitness-related variation in wild animals

野生动物种群越来越多地受到新的和强大的选择压力的挑战，这些压力是由迅速和强烈的人为环境变化造成的，包括传染病的传播、外来和入侵物种的引入以及全球变暖。与此同时，人类活动正在迅速消除或破坏栖息地，导致种群数量下降，并限制种群间的基因交流。这些因素加在一起会限制种群的适应能力，降低个体的适应性，最终危及种群和物种的持久性。因此，了解调节自然种群适应度变化和适应性进化的生态和进化过程对维持生物多样性至关重要。在这里，我建议使用一个长期的，以个体为基础的研究在黑貂岛国家公园保护区，新斯科舍省，作为一个模型来测试各种新兴的假设，这些假设与野生动物的遗传基础和进化动力学有关。黑貂岛马项目以其他非常成功的基于个体的研究为蓝本，如在阿尔伯塔省的拉姆山（大角羊）和苏格兰的圣基尔达（索伊羊）的研究，在许多方面都是值得注意的。特别是，该系统允许研究大量多样的表型特征，这些特征被认为与适应性有关；孤立但庞大的人口（目前人口规模约为500人）提供了快速测试新想法所需的统计能力；而且，现成的马基因组工具为在自然条件下进行基于基因组的研究提供了一个出色的平台。自2008年以来，该研究每年夏天对近1150只已知个体进行各种与健康相关的特征测量，已经是世界上同类大型脊椎动物中规模最大的研究之一。我提出的研究分为四个短期目标，以实现我的主要职业目标，即提高我们对调节野生动物种群适应性变化和进化的生态和进化过程的理解。采用综合的、多学科的方法，结合野外生物学、分子生态学、寄生虫学、数量遗传学和基因组学，我将：1)对肠道细菌微生物群结构和功能变化的原因和后果进行大规模调查；II)研究复杂混合寄生虫感染的生态学和进化；III)表征适合度相关性状的基因组结构和适应进化；4)量化近交抑制，了解调节其强度和遗传结构的因素。这项研究将有助于建立一个国际公认的野生动物进化和生态遗传学研究项目，并为加拿大和国际上保护和管理野生动物和濒危物种提供所需的工具和知识。

Wildlife populations are increasingly challenged by new and strong selective pressures resulting from rapid and intense anthropogenic environmental change, including the spread of infectious diseases, introduction of exotic and invasive species, and global warming. Simultaneously, human activity is rapidly removing or fragmenting habitat, leading to population declines and restricting genetic exchange among populations. Together, these factors can limit the ability of populations to adapt, decrease individual fitness, and ultimately compromise the persistence of populations and species. Understanding the ecological and evolutionary processes modulating variation in fitness and adaptive evolution in natural populations is therefore critical for maintaining biodiversity. Here, I suggest using a long-term, individual-based study of feral horses at Sable Island National Park Reserve, Nova Scotia, as a model to test a variety of emerging hypotheses related to the genetic basis and evolutionary dynamics of fitness-related traits in wild animals. The Sable Island horse project, modelled on other highly successful individual-based studies such as those at Ram Mountain in Alberta (bighorn sheep) and St-Kilda in Scotland (Soay sheep), is remarkable in a number of ways. In particular, the system allows for the study of a large and diverse array of phenotypic traits putatively linked to fitness; the isolated but large population (current population size ~500) provides statistical power needed to rapidly test new ideas; and readily available equine genomic tools makes for an outstanding platform to conduct genomic-based research under natural conditions. With almost 1,150 known individuals measured at a variety of fitness-related traits each summer since 2008, the study is already one of the world's largest of its kind for a large vertebrate. My proposed research is divided into four short-term objectives contributing to my principal career goal of improving our understanding of the ecological and evolutionary processes modulating variation in fitness and adaptive evolution in wildlife populations. Using an integrative, multi-disciplinary approach combining field biology, molecular ecology, parasitology, quantitative genetics, and genomics, I will: I) Conduct a large-scale investigation of the causes and consequences of variation in gut bacterial microbiome structure and function; II) Study the ecology and evolution of complex mixed parasitic infections; III) Characterize the genomic architecture of fitness-related traits and adaptive evolution; and IV) Quantify inbreeding depression and understand the factors modulating its intensity and genetic architecture. The proposed research will contribute to developing an internationally recognized research program in evolutionary and ecological genetics of wild animals, and provide tools and knowledge needed for conserving and managing wildlife and endangered species in Canada and internationally.