Molecular phylogeny and speciation in a regional fauna

我的研究计划的中心目标是了解生物多样性的起源和持久性在多个空间和时间尺度-从特定遗传位点的等位基因变异到物种在地理尺度上的组合，以及跨越几代人到数百万年的分歧。我的研究计划的长期主题是：（i）文件的进化分歧的模式内和物种之间，（ii）测试有关的起源和这种变化的持续性和过程的相关性，如自然选择，杂交和vicariance的假设，和（iii）将这些知识应用到生物多样性的保护。我研究北美西北部和北极的淡水和海洋鱼类，并将生态学和遗传学方法结合起来，以解决有机体和进化生物学中也具有重要保护应用的这些中心问题。我的研究提出了一些问题，如：什么是物种之间的相互关系在一个分支和什么样的地理过程（例如，地质构造、海平面变化、气候变化）塑造了现存的多样性？当物种接触时，它们会杂交吗？如果是的话，杂交的频率和命运能告诉我们什么关于驱动物种形成的地理，生态和遗传过程？什么样的生境特征影响同种种群适应性和中性变异的程度和模式？该提案的关键主题是研究接触的物种，以测试有关杂交的全基因组范围和生殖隔离的遗传基础的假设。我利用两种红点鲑，S。alpinus（北极红点鲑）和S.产于阿拉斯加西部的马尔马（多莉瓦登）。我将建立在我们详细的核DNA微卫星分析，通过使用基因组测序方法来更好地确定基因组的范围和特定区域，以区分这些物种在面对基因流，展示这些物种之间的接触和杂交。这项工作还将探讨假设的生活史字符位移利用多个异域和同域种群的两个物种，表达了全方位的淡水居民和溯河产卵（searun）的生活史的发生。我的研究的意义和新奇包括：（1）了解一个基本的未知的进化（生物多样性的起源和持久性），（ii）提供急需的培训，在加拿大的生物多样性研究，（iii）说明栖息地和生物多样性持久性之间的密切联系，保护评估和行动的关键，和（iv）提供一些重点（i）-（iii）在北方地区，这是相对不足，在加拿大环境变化的风险越来越大。

The central goal of my research program is to understand the origins and persistence of biodiversity at multiple spatial and temporal scales - from allelic variation at specific genetic loci to the assemblage of species at a biogeographic scale, and divergences spanning a few generations to millions of years. The long-term themes of my research program are to: (i) document the patterns of evolutionary divergence within and among species, (ii) test hypotheses concerning the origins and persistence of this variation and the relevance of processes such natural selection, hybridization, and vicariance, and (iii) to apply this knowledge to the conservation of biodiversity. I study freshwater and marine fishes in northwestern North America and the Arctic and integrate methods in ecology and genetics to address these central inquiries in organismal and evolutionary biology that also have important conservation applications. My research poses questions such as: what are the interrelationships amongst species within a clade and what biogeographic processes (e.g., tectonics, sea level changes, climate change) have shaped extant diversity? When species come into contact, do they hybridize and if so, what can the frequency and fate of hybrids tell us about the geographic, ecological and genetic processes driving speciation? What habitat features influence the extent and patterns of adaptive and neutral variation among conspecific populations? The key theme of this proposal examines species that come into contact to test hypotheses concerning the genome-wide extent of hybridization and the genetic basis of reproductive isolation. I exploit the occurrence of multiple areas of contact between two species of Salvelinus, S. alpinus (Arctic char) and S. malma (Dolly Varden) in western Alaska. I will build on our detailed nuclear DNA microsatellite analyses demonstrating contact and hybridization between these species by using genomic sequencing approaches to better pinpoint the extent and specific regions of the genome that distinguish these species in the face of gene flow. This work will also explore the hypothesis of life history character displacement by exploiting the occurrence of multiple allopatric and sympatric populations of both species which express the full range of freshwater resident and anadromous (searun) life histories. The significance and novelty of my research includes:(1) understanding a fundamental unknown in evolution (the origins and persistence of biodiversity),(ii) providing much needed training in biodiversity research in Canada, (iii) illustrating the intimate connection between habitat and biodiversity persistence critical for conservation assessment and action, and (iv) providing some emphasis for (i)-(iii) in northern areas which are relatively understudied and at increasing risk in Canada from environmental change.