Phylogenetics, biogeography, and evolution of fishes

我的研究计划的中心重点是调查鱼类生物多样性的进化模式和过程。我使用系统发育树作为宝贵的工具来理解分类学和物种多样性，地理和古地理对谱系多样性的影响，栖息地类型之间变化的宏观进化后果，以及新的解剖系统中的适应性进化变化。在这里提出的工作中，我的研究小组将推断两类鱼的系统发育关系：鼓鱼(石斑鱼科)和新热带电刀鱼(裸鱼形目)。这些类群的系统发育树将形成一个基础，以了解水生栖息地转变的进化，以及电作为感觉方式的进化。 鼓鱼是一种全球分布的鱼类家族，主要是海洋鱼类，但也包括北美、南美洲和亚洲特有的淡水物种。这些鱼类是研究海洋和淡水栖息地之间过渡演变的一个很好的模式系统。为了重建Drum的进化史，我们将使用靶向序列捕获和下一代DNA测序来构建系统发育树，以采集大约1000个基因。我们将利用系统发生学来检验关于海洋到淡水栖息地的转变如何改变谱系和形态多样化模式的假说。我们还将利用收集的大量DNA序列数据来研究涉及渗透调节和视觉适应新环境的基因的进化。这项研究将阐明栖息地之间的过渡如何影响大空间和时间尺度的进化。 电刀鱼是新热带鱼类的一个目，利用电力进行通讯和导航。由于它们的电信号易于量化和分析，体操形式是神经生物学和行为学研究的重要模型系统。然而，裸子植物物种之间的进化关系却鲜为人知。我的实验室将通过使用定向序列捕获来重建这一组的系统发育关系。利用过去十年积累的大量通信信号数据库，我们将检验这样一个假设，即为避免错配而进行的自然选择推动了信号分歧的进化。使用序列捕获产生的遗传数据，我们将检查与电信号产生相关的基因的进化速度和模式。这项工作将阐明通讯信号是如何进化的，并为对这一重要鱼类群体的各种长期研究提供一个框架。 这项研究将为本科生和研究生提供生物多样性、分子系统学和进化生物学方面的培训，并将有助于了解进化模式和过程的基础知识。

The central focus of my research program is to investigate evolutionary patterns and processes of biodiversity in fishes. I use phylogenetic trees as invaluable tools for understanding taxonomy and species diversity, the effects of geography and paleogeography on lineage diversity, macroevolutionary consequences of shifts between habitat types, and adaptive evolutionary change in novel anatomical systems. In the work proposed here, my research group will infer phylogenetic relationships for two groups of fishes: the drum (Sciaenidae) and the Neotropical electric knifefishes (Gymnotiformes). Phylogenetic trees for these groups will form a basis for understanding the evolution of aquatic habitat transitions, and the evolution of electricity as a sensory modality. The drum (Sciaendiae) are a globally-distributed family of fishes that are mainly marine, but include endemic freshwater species in North America, South America, and Asia. These fishes are an excellent model system for studying the evolution of transitions between marine and freshwater habitats. To reconstruct the evolutionary history of drum, we will build a phylogenetic tree using targeted sequence capture and next-generation DNA sequencing to sample approximately 1000 genes. We will use the phylogeny to test hypotheses about how marine to freshwater habitat transitions alter lineage and morphological diversification patterns. We will also leverage the large amounts of collected DNA sequence data to examine the evolution of genes involved in osmoregulation and visual adaptation to new environments. This research will illuminate how transitions between habitats affect evolution at large spatial and temporal scales. The electric knifefishes (Gymnotiformes) are an order of neotropical fishes that use electricity for communication and navigation. Because their electric sigals are amenable to quantification and analysis, gymnotiforms are an important model system for neurobiology and behavioural studies. However, evolutionary relationships among gymnotiform species are poorly understood. My lab will reconstruct the phylogenetic relationships of this group by using targeted sequence capture. Using a large library of communication signal data accumulated over the past decade, we will test the hypothesis that natural selection to avoid mismating drives evolution of signal divergence. Using genetic data produced by sequence capture, we will examine rates and patterns of evolution in genes associated with electric signal production. This work will clarify how communication signals evolve, and provide a framework for a variety of long-term studies on this important group of fishes. This research will provide training for undergraduate and graduate students in biodiversity, molecular systematics, and evolutionary biology, and will contribute to fundamental knowledge of evolutionary patterns and processes.