Dissertation Research: An investigation of isolating mechanisms between sister species in the genus Empidonax

对新物种形成过程的研究仍然是进化生物学研究的一个活跃领域。当生物群体之间的基因交换出现障碍时，新物种就形成了。当密切相关的物种在地理重叠的地区相互作用时，可以测试特定类型的障碍的强度。该项目研究了两种密切相关的北美鸣禽之间遗传交换的两个重要潜在障碍的强度。太平洋坡霸鹟和Cordilloughflyccatchers在栖息地的偏好不同，在大部分的范围和不同的歌曲，一个重要的特征，在配偶选择。它们共同出现在两个领域。在一个地区，基因交换相对普遍，而在另一个地区，基因交换受到限制。本研究将结合地理信息系统的生物气候分析、交配行为的实验测试和遗传分析，探讨栖息地偏好和交配行为的差异对基因交换的影响。本研究采用综合方法研究新物种形成的关键过程。两个具有不同进化动态的地理接触区域的存在提供了一个独特的机会来比较不同基因交流障碍的相对强度。了解调节密切相关物种之间基因交换的因素具有重要的保护意义，因为研究表明，稀有或受威胁物种与近亲之间的基因交换可能产生负面影响。外联活动将涉及K-12学生和本科生将作为研究计划的一部分进行指导。

Examination of the processes involved in the formation of new species remains an active area of investigation in evolutionary biology. New species form when barriers to the exchange of genes arise between groups of organisms. The strength of specific types of barriers can be tested when closely related species interact in areas of geographic overlap. This project examines the strength of two important potential barriers to genetic exchange between two closely related North American songbirds. Pacific-slope flycatchers and Cordilleran flycatchers differ in habitat preference across much of their ranges and differ in song, a trait important in mate choice. They co-occur in two areas. In one area, genetic exchange is relatively common, whereas in the other it is restricted. By combining GIS-based bioclimatic analysis and experimental tests of mating behavior with genetic analysis, this study will examine the effects of differences in habitat preference and mating behavior on the exchange of genes. This study utilizes an integrated approach to investigate key processes involved in the formation of new species. The existence of two areas of geographic contact with differing evolutionary dynamics presents a unique opportunity to compare the relative strengths of different barriers to gene exchange. Understanding the factors that regulate the exchange of genes between closely related species has important conservation implications, as research has demonstrated potentially negative consequences of genetic exchange between rare or threatened species and close relatives. Outreach activities will involve K-12 students and undergraduates will be mentored as part of the research plan.