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？Lasiopogon属的强盗苍蝇是一种分布广泛的天敌昆虫，它们在许多环境中捕食，如沙丘、海滩、小径、溪边和山艾树景观。栖息习性或季节性羽化时间等专门化为范围重叠的物种提供了一种减少竞争的方法。该项目的目标是比较北美Lasiopogon的60个物种在地理范围、生态位和形态上的多样性模式和相似性，以揭示给定物种何时何地分裂，以及区域群落(即，它与谁一起进化)如何影响这种多样性。了解区域和地方尺度上的适应过程将有助于展示环境线索和物种之间的相互作用如何维持和促进生物多样性，为物种对不断变化的环境的潜在反应提供经验教训。这项研究将促进分类学的专门知识和对不同但研究不足的昆虫(强盗苍蝇)的培训。此外，由于许多Lasiopogon物种对栖息地的要求高度专业化，这项工作将为研究城市扩展、人工灌溉和气候变化导致的群落变化提供数据。一名本科生将接受Asilidae分类学和生物多样性研究方面的培训，这项研究的分布和生态信息将在一般和特定于分类群的网站上分享。物种生态位是它们与群落其他成员的相互作用及其系统发育历史的升华。这项研究将通过对多个基因座的测序来估计北美Lasiopogon之间的进化关系。生物多样性指数将从博物馆标本和样本中估计微生态位特征和生态位模型。然后将使用系统发育比较方法来研究不同空间尺度上的生态专门化和形态特征置换对多样性和群落聚集的影响。这项研究设计将揭示生态和形态差异是在物种分化期间或之后积累的，以及哪些变异轴(粗略或精细的生态、形态、物候学)在推动特征置换和竞争性专门化方面影响更大。

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.