DISSERTATION RESEARCH: Speciation, niche divergence, and character displacement at multiple scales in Lasiopogon robber flies (Diptera: Asilidae)

当物种之间的相互作用可能限制潜在的重叠时，群落中不同的生态位是如何填充的？掠蝇属的掠蝇是一种分布广泛的昆虫捕食者，它们在许多环境中捕食，如沙丘、海滩、小径、河边和山艾树景观。栖息习惯或季节性出现时间等特化为重叠范围的物种提供了一种减少竞争的方法。这个项目的目标是比较北美洲60个Lasiopogon物种在地理范围、生态位和形态上的多样化模式和相似性，不仅揭示特定物种分裂的时间和地点，而且揭示区域群落（即与谁一起进化）如何影响这种多样化。了解区域和局部尺度的适应过程将有助于揭示环境因素和物种之间的相互作用如何维持和促进生物多样性，为物种对变化环境的潜在反应提供经验教训。这项研究将促进对一种多样化但尚未得到充分研究的昆虫群体（盗蝇）的分类学专业知识和培训。此外，由于许多Lasiopogon物种具有高度专业化的栖息地需求，本研究将为研究城市扩张、人工灌溉和气候变化导致的群落变化提供数据。培养一名本科生，从事无蚊科分类与生物多样性研究、分布与生态信息研究。这项研究的结果将在一般和特定分类群的网站上分享。物种生态位是它们与群落其他成员相互作用及其系统发育历史的结晶。本研究将通过对多个基因座的测序来估计北美Lasiopogon的进化关系。微生态特征和生态位模型将由pi从博物馆标本和样品中估计。然后，系统发育比较方法将用于研究不同空间尺度的生态专业化和形态特征位移对多样性和群落聚集的影响。本研究设计将揭示物种分化期间或之后是否积累了生态和形态差异，以及哪种变异轴（粗尺度或细尺度生态学、形态学、物候学）在促进特征位移和竞争性专业化方面更有影响力。

How are distinct niches in communities filled when interactions among species may constrain potential overlap? Robber flies in the genus Lasiopogon are a widespread group of insect predators that hunt in many environments, such as dunes, beaches, trails, streamsides, and sagebrush landscapes. Specializations such as perching habits or seasonal emergence times provide a way for species with overlapping ranges to reduce competition. The goal of this project is to compare diversification patterns and similarities in geographic range, niche, and morphology throughout the 60 species of North American Lasiopogon to uncover not just when and where a given species split, but how regional communities (i.e., who it evolved with) influenced this diversification. Understanding the processes of adaptation at regional and local scales will help show how environmental cues and interactions among species maintain and promote biodiversity, providing lessons about potential responses of species to shifting environments. This research will promote taxonomic expertise and training in a diverse but understudied group of insects (robber flies). Furthermore, since many Lasiopogon species have highly specialized habitat requirements, this work will provide data for studying community changes precipitated by urban spread, manmade irrigation, and climate change. An undergraduate student will be trained in Asilidae taxonomic and biodiversity research, and distributional and ecological information
from this study will be shared on general and taxon-specific websites. Species niches are a distillation of their interactions with other members of the community and their phylogenetic history. This research will estimate evolutionary relationships among North American Lasiopogon from sequencing multiple loci. Microniche characteristics and ecological niche models will be estimated from museum specimens and samples by the PIs. Phylogenetic comparative methods will then be used to examine the effects of ecological specialization at different spatial scales and morphological character displacement on diversification and community assembly. This study design will reveal whether ecological and morphological differences accumulated during or after species divergence, and which axes of variation (coarse- or fine-scaled ecology, morphology, phenology) have been more influential in fueling character displacement and competitive specialization.