CAREER: Teaching Modern Biodiversity Science from Fieldwork to Phylogeny: Diversity, Systematics, & Evolution of Ecologically Promiscuous Aquatic Beetles

生活在淡水和陆地栖息地的动物面临着截然不同的生理和形态挑战，包括它们如何呼吸、移动、进食和繁殖。虽然动物，特别是昆虫，在它们的进化史上多次在这些极端栖息地之间转换，但人们对这些主要的水陆过渡是如何发生的，以及它们如何影响物种的多样性和分布，知之甚少。这项研究将集中在一个昆虫群上，它包含了从开阔水域到陆地落叶层的广泛栖息地的物种。通过重建这一谱系的进化史，研究人员将研究它在何时、何地以及如何跨越水陆边界进化，并将这一群体作为模型来理解其他生物如何经历主要的栖息地转移。了解昆虫如何经历重大的生态转变，以及这些转变的影响，可以提高我们对动物如何应对不断变化的气候和环境的理解。这项研究的更广泛影响包括培养了两名生物多样性科学方面的博士生。开设生物多样性监测与评估本科课程，教授测量地理距离上物种丰富度和更替的理论、方法和实践。本课程将包括与东道国机构一起在苏里南和圭亚那进行实地考察。本研究将使用食水甲虫（鞘翅目：亲水甲虫科）作为模型，在多个进化尺度上研究栖息地的变化：枝、种和种群。食水甲虫是一个包括水生和陆地生态位之间许多独立过渡的谱系。研究人员将(1)推断500个物种的分子系统发育，以确定栖息地转移的数量、时间和位置，并测试栖息地类型之间多样化率的相关变化；(2)通过对chasmogenus -类群的物种水平分类修订，包括对大约50个新物种的描述，再加上形态学-分子系统发育，研究与栖息地变化相关的精细尺度形态进化。(3)利用RAD-seq方法对3个独立支系中具有不同生态位的12个物种的遗传结构进行了研究，揭示了生境相关和谱系特异性对共分布种群的影响。综合起来，这些方法将提供新的见解，了解从最近到数亿年前，水陆转换如何改变了过去的进化轨迹，并告知生物体如何应对未来栖息地的变化。

Animals living in freshwater and terrestrial habitats are presented with dramatically different physiological and morphological challenges, including how they breathe, move, feed, and reproduce. While animals, particularly insects, have shifted between these habitat extremes many times over their evolutionary history, little is known of how these major aquatic-terrestrial transitions occur or how they affect the diversity and distribution of species. This research will focus on an insect group that contains species with a wide range of habitats from open waters to terrestrial leaf litter. By reconstructing the evolutionary history of this lineage, the researchers will examine when, where, and how it has evolved across the aquatic-terrestrial boundary, and use the group as a model to understand how other organisms may have undergone major habitat shifts. Understanding how insects undergo major ecological transitions and what implications these transitions have can improve our understanding of how animals respond to changing climates and altered environments. The broader impacts of this research include the training of two PhD students in the biodiversity sciences. A new undergraduate course in biodiversity monitoring and assessment will be developed to teach the theory, methods, and practice of measuring species richness and turnover over geographic distances. This course will include fieldwork in Suriname and Guyana in conjunction with host country institutions. This research will use water scavenger beetles (Coleoptera: Hydrophilidae), a lineage that encompasses many independent transitions between aquatic and terrestrial niches, as a model to examine habitat shifts at multiple evolutionary scales: clades, species, and populations. Researchers will (1) infer a 500-species molecular phylogeny to identify the number, timing, and placement of habitat shifts and test for associated changes in diversification rate between habitat types, (2) examine the fine-scale morphological evolution associated with changing habitats through a species-level taxonomic revision of the Chasmogenus-group, including the description of approximately 50 new species, coupled with a morphological-molecular phylogeny, and (3) disentangle habitat-associated from lineage-specific effects on co-distributed populations by using RAD-seq methods to examine the genetic structure of 12 species with diverse ecological niches across three independent clades. Taken together, these approaches will provide new insights into how aquatic-terrestrial shifts have altered past evolutionary trajectories from the recent to hundreds of millions of years before present, and inform how organisms may respond to changing habitats in the future.