Phylogenetics, biogeography, and evolution of fishes

我的研究计划的总体目标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强大的工具来理解分类学和物种多样性，地理和古地理对分布和多样性的影响，栖息地类型之间变化的宏观进化后果，以及适应性进化变化。在这里提出的工作中，我的研究小组将使用尖端基因组分析来调查北美和南美经历了从海洋栖息地到淡水栖息地的进化过渡的谱系。在北美，我们将重建深水/四角海豚复合体的进化史，这是一个占据着深水和寒冷水生栖息地的谱系。深水雕像分布在加拿大最深的淡水湖中，从安大略湖到大熊湖，被称为冰川残留物，因为它可能起源于冰川将海水推入大陆地区。它的近亲是分布在北极各地的海生四角海豚。有几个种群似乎入侵了加拿大北极群岛的淡水湖，但他们的祖先尚不清楚。为了阐明这些物种和种群之间的关系，我们将从斯卡宾基因组中收集数据，并推断谱系历史。我们将评估冰川作用在决定海洋和淡水生境之间的分布和驱动过渡方面的作用，并将确定与淡水入侵相关的分子变化。在南美洲，我们将研究美洲比目鱼(Achiridae)，这是一群主要生活在海洋，但包括亚马逊河淡水物种的比目鱼，使它们成为研究海洋和淡水栖息地之间过渡演变的极佳模式系统。为了重建角果类的进化史，我们将建立一个基于&gt；2000基因序列的系统发育树。我们将利用系统发生学来测试古地理事件是如何推动栖息地转变的，以及这些转变是否改变了谱系和形态多样化。我们还将研究涉及渗透调节和视觉适应新环境的基因的进化。这项研究将阐明主要栖息地转变的进化原因和后果。这项工作对理解群落聚集、物种多样性的大规模模式以及地理事件(包括冰川、海平面变化和山脉建设)如何影响生物多样性具有重要意义。确定与海洋和淡水生境有关的基因与水产养殖和渔业生物学有关。了解加拿大鱼类的进化历史和种群结构对管理和保护很重要。北极气候变暖的持续影响使得了解北方鱼类和水生生态系统的生物学成为优先事项。

The overall goal of my research program is to investigate evolutionary patterns and processes of biodiversity in fishes. I use phylogenetic trees as powerful tools to understand taxonomy and species diversity, the effects of geography and paleogeography on distributions and diversity, macroevolutionary consequences of shifts between habitat types, and adaptive evolutionary change. In the work proposed here, my research group will use cutting-edge genomic analyses to investigate lineages that underwent evolutionary transitions from marine to freshwater habitats in both North and South America. In North America, we will reconstruct the evolutionary history of the deepwater/fourhorn sculpin complex, a lineage that occupies deep and cold aquatic habitats. The deepwater sculpin is distributed in the deepest freshwater lakes of Canada, from Lake Ontario to Great Bear Lake, and is called a glacial relict because it likely originated when glaciers pushed marine waters into continental areas. Its closest relative is the marine fourhorn sculpin, distributed across the Arctic. Several populations of the fourhorn sculpin appear to have invaded freshwater lakes of the Canadian Arctic Archipelago, but their ancestry is unclear. To elucidate the relationships among these species and populations, we will collect data from sculpin genomes and infer lineage history. We will assess the role of glaciation in determining distributions and driving transitions between marine and freshwater habitats, and we will identify molecular changes associated with the invasion of freshwater. In South America, we will investigate American soles (Achiridae), a group of flatfishes that are mainly marine, but include freshwater species in the Amazon river, making them an excellent model system for studying the evolution of transitions between marine and freshwater habitats. To reconstruct the evolutionary history of achirids, we will build a phylogenetic tree based on sequences from >2000 genes. We will use the phylogeny to test how paleogeographic events drove habitat transitions and whether these transitions altered lineage and morphological diversification. We will also examine the evolution of genes involved in osmoregulation and visual adaptation to new environments. This research will illuminate the evolutionary causes and consequences of major habitat transitions. The work has implications for understanding community assembly, largescale patterns of species diversity, and how geographic events, including glaciation, sea level changes, and mountain building, affect biodiversity. Determining the genes associated with marine and freshwater habitats has relevance for aquaculture and fisheries biology. Understanding the evolutionary history and population structure of Canadian fishes is important for management and conservation. The ongoing effects of climate warming in the Arctic make understanding the biology of northern fishes and aquatic ecosystems a priority.