DISSERTATION RESEARCH: A large-scale, multilocus, coalescent-based analysis of ecological zonation and population differentiation in Andean birds

覆盖在南美洲热带山脉上的潮湿森林维持着世界上最高多样性的鸟类物种之一。这个巨大的鸟类群分布在不同的海拔地区，沿着安第斯山脉狭窄的云雾林地带沿着，从玻利维亚到委内瑞拉。来自该栖息地的鸟类的地理分布被低海拔的干旱山谷分割，这是种群间杂交的障碍。这些山谷造成的隔离有可能促进鸟类种群的遗传和表型分化，并可能最终导致新物种的形成。在冰川时代气候变化导致森林沿着山坡上下移动的过程中，这种多样性可能得到了加强。例如，在冰川期最寒冷的时期，山地森林向山下移动了几百米，在山谷屏障之间架起了差距，促进了以前孤立的种群的接触。这些想法是通过大规模的比较分析人口分化的遗传学。将在安第斯山脉两个大山谷的斜坡上研究大约250种鸟类。五个物种将是一个更深入的遗传分析的主题，以推断与栖息地运动相关的历史因素。这项调查不仅将提供新的见解的机制，推动多样化，但也将增加我们的知识，生物多样性的保护。此外，它还将加强对哥伦比亚和委内瑞拉女大学生的生物学培训。这位研究生正在指导两篇学生论文，并向大学和国家公园的工作人员做了演讲。

The humid forests that cover the tropical mountains of South America sustain one of the highest diversity of bird species in the world. This huge avifauna is packed in different elevation zones and stretches along the narrow strip of cloud forest of the Andes, from Bolivia to Venezuela. The geographic distributions of the birds from this habitat are fragmented by low-elevation dry valleys, which function as barriers to interbreeding between populations. The isolation imposed by these valleys has the potential to promote the genetic and phenotypic divergence of bird populations, and may ultimately result in the formation of new species. This diversification could have been intensified during the forest movements up and down the mountain slopes that resulted from climatic changes in the glacial age. For example, in the coldest periods of the glaciations, montane forests moved downslope several hundred meters bridging the gap across valley barriers and facilitating the contact of formerly isolated populations. These ideas are addressed by means of a large-scale comparative analysis of the genetics of population divergence. Approximately 250 species of birds will be studied in the slopes of two large valleys in the Andes. Five species will be the subjects of a more intensive genetic analysis to infer historical factors associated with habitat movements. This investigation not only will provide new insights into the mechanisms driving diversification, but also will increase our knowledge of biodiversity for its conservation. Furthermore it will enhance training in biology to undergraduate female students in Colombia and Venezuela. The graduate student is mentoring two student theses and has made presentations to university and national park staff.