Evolution of High Latitude Birds

高纬度鸟类的进化

• 批准号: RGPIN-2014-03851
• 负责人: Burg, Theresa
• 金额: $ 2.48万
• 依托单位: University of Lethbridge
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610686
• 关键词: Evolution; Latitude; Birds

The evolution of high latitude species is linked to both historical and contemporary environmental changes. One way to understand the historical processes influencing the species’ distribution is through the use of molecular markers. These markers retain information on historical events in addition to contemporary processes. Northern North America contains several areas of secondary contact between populations from different Pleistocene refugia that were isolated for thousands of years. My current research program uses a comparative approach to investigate population genetic structure. By understanding how past climate changes and landscape features have shaped contemporary populations, we can better understand their population dynamics, and metapopulation functioning and perhaps predict how they will respond to future climate change. In addition, we can gain further insights into ecological diversification by focusing on closely related sympatric species. My long term goals focus on the role of landscape features and historical range shifts on population level processes and patterns of population connectivity. My research has revealed contrasting genetic patterns in some co-distributed species with similar life history patterns and habitat requirements. Some of the patterns correspond to known physical barriers, but others do not and warrant further study to determine the barriers to dispersal. The patterns of postglacial colonization for my study species are now better understood as a direct result of my research. The short term goals of my research program are to study: 1) micro- and macro-geographic population structure in species with mixed migration strategies, and 2) intra- and inter-specific contact zones to examine microgeographic landscape genetics. The combination of short term projects also allows us to study the speciation process. For example, what is the influence of migratory behaviour on intraspecific gene flow or more specifically do resident populations have higher levels of population structure than migratory populations of the same species? In the last few years, major advances in genetic analyses have occurred allowing researchers to answer questions that were not possible even a decade ago. GIS technologies and Bayesian analyses now allow me to create historical range maps for individual species using paleoclimate data and compare these to our genetic data. Combining the newer and more powerful analyses with traditional markers and a larger number of species will allow us to better understand evolutionary processes. Using genetic tools, I will determine if geographic variation is the result of restricted gene flow or other ecological factors. By employing a combination of mitochondrial (mtDNA) and nuclear (microsatellite and single nucleotide polymorphisms (SNPs)) loci, I will be able to obtain a more complete and accurate picture of rangewide gene flow and fine scale population genetic structure. By examining fine scale differences in western North America species, such as purple finch, and adding data on species with mixed migration strategies, we will gain a better understanding of how gene flow is occurring as a result of behavioural and ecological differences. Furthermore by comparing data from different classes of highly variable markers and the different species occupying similar geographic areas, we can assess whether or not there is a common genetic signature on the patterns of variation and population structure.

高纬度物种的进化与历史和当代环境变化有关。了解影响物种分布的历史过程的一种方法是使用分子标记。这些标记除了当代进程之外还保留了历史事件的信息。北美洲北部包含几个来自不同更新世避难所的种群之间二次接触的区域，这些避难所被隔离了数千年。我目前的研究项目使用比较方法来研究群体遗传结构。通过了解过去的气候变化和景观特征如何塑造当代人口，我们可以更好地了解他们的人口动态和集合人口功能，或许还可以预测他们将如何应对未来的气候变化。此外，我们可以通过关注密切相关的同域物种来进一步了解生态多样性。 我的长期目标侧重于景观特征和历史范围变化对人口水平过程和人口连通模式的作用。我的研究揭示了一些具有相似生活史模式和栖息地要求的共同分布物种的截然不同的遗传模式。有些模式对应于已知的物理障碍，但其他模式则不然，需要进一步研究以确定扩散障碍。作为我的研究的直接结果，我的研究物种的冰河后殖民模式现在得到了更好的理解。我的研究计划的短期目标是研究：1）具有混合迁徙策略的物种的微观和宏观地理种群结构，2）种内和种间接触区，以检查微观地理景观遗传学。短期项目的结合也使我们能够研究物种形成过程。例如，迁徙行为对种内基因流的影响是什么，或者更具体地说，同一物种的常住种群是否比迁徙种群具有更高水平的种群结构？ 在过去的几年里，基因分析领域取得了重大进展，使研究人员能够回答十年前不可能的问题。 GIS 技术和贝叶斯分析现在允许我使用古气候数据为各个物种创建历史范围图，并将其与我们的遗传数据进行比较。将更新、更强大的分析与传统标记和更多物种相结合将使我们能够更好地了解进化过程。使用遗传工具，我将确定地理变异是否是基因流动受限或其他生态因素的结果。通过采用线粒体（mtDNA）和核（微卫星和单核苷酸多态性（SNP））基因座的组合，我将能够获得更完整和准确的大范围基因流和精细群体遗传结构的图像。 通过研究北美洲西部物种（例如紫雀）的精细尺度差异，并添加具有混合迁徙策略的物种数据，我们将更好地了解行为和生态差异如何导致基因流动。此外，通过比较不同类别的高度可变标记和占据相似地理区域的不同物种的数据，我们可以评估变异模式和种群结构是否存在共同的遗传特征。