Dissertation Research: Investigating genomic signatures of speciation in tropical montane kingfishers (Aves: Halcyonidae)

本研究将利用基因组数据来研究导致两种山翠鸟从一个共同祖先分化的进化机制。这两种密切相关的鸟类都生活在巴布亚新几内亚的高地;一种出现在低海拔地区，另一种出现在高海拔地区。科学家们早就知道，像巴布亚新几内亚这样的热带山脉，其植物和动物的种类比基于其小的总面积而预期的要多得多。然而，一个基本的未回答的问题是，随机或适应性的进化过程是否更重要，在产生这种增加的生物多样性。这项研究将使用数学模型和从野外和博物馆标本中收集的DNA序列数据来测试这两个物种进化分歧的替代解释。确定新物种进化的过程对于理解地球上生命的历史和预测环境的复杂性和变化如何导致新的生物多样性非常重要。研究结果可为山地鸟类的保护管理提供重要参考。此外，该项目还包括建立公共博物馆展览和其他教育宣传活动。具有不同海拔范围的姐妹物种为理解进化过程与地理和环境复杂性之间的相互作用提供了一个强大的系统。该项目将探索Syma属森林翠鸟（鸟类：Halcyonidae）的全基因组分化的模式和驱动因素，这是一个年轻的物种，在巴布亚新几内亚与parapatric低地和高地分布。研究人员将从野外收集的样本和自然历史博物馆的藏品中生成单核苷酸多态性数据和全基因组DNA序列。利用这些数据，他们将描述两个物种的地理分布模式，推断人口统计学历史，估计系统发育关系，进行物种划界，并评估中性和适应性进化过程的相对贡献。结合起来，这些分析将提供一个测试的假设，由于破坏性的自然选择跨越海拔梯度的Syma生态物种形成。这项研究还将揭示有关热带山地系统物种丰富度不成比例的进化机制的重要线索。

This study will use genomic data to investigate the evolutionary mechanisms that led to the divergence of two Mountain Kingfisher species from a single common ancestor. Both of these two closely related bird species live in the highlands of Papua New Guinea; one species occurs at lower elevations, the other occurs at higher elevations. Scientists have long known that tropical mountain ranges, like these in Papua New Guinea, have many more species of plants and animals than expected based on their small total area. However, a fundamental unanswered question is whether random or adaptive evolutionary processes are more important in generating this increased biological diversity. This study will use mathematical models and DNA sequence data collected from field and museum specimens to test alternate explanations for the evolutionary divergence of these two species. Identifying the processes responsible for the evolution of new species is important for understanding the history of life on Earth and for predicting how environmental complexity and change leads to new biological diversity. Results of this work are expected to provide important insights for conservation management of montane bird species. In addition, the project includes creation of public museum displays and other educational outreach activities. Sister species with differing elevational ranges present a powerful system for understanding the interplay between evolutionary processes and geographic and environmental complexity. This project will explore patterns and drivers of whole genomic differentiation in Syma genus forest kingfishers (Aves: Halcyonidae), a young species pair with parapatric lowland and highland distributions in Papua New Guinea. The researchers will generate single nucleotide polymorphism data and whole genome DNA sequences from samples collected in the field and from natural history museum collections. Using these data they will describe phylogeographic patterns and infer demographic history in both species, estimate phylogenetic relationships and conduct species delimitation, and assess the relative contribution of neutral and adaptive evolutionary processes. In combination, these analyses will provide a test of a hypothesis of ecological speciation in Syma due to disruptive natural selection across an elevational gradient. The research will additionally reveal important clues regarding the evolutionary mechanisms responsible for disproportionate species richness in tropical montane systems.