DISSERTATION RESEARCH: Inferring the Evolutionary History of Arthropods Associated with Pitcher Plants using Phylogeographic Concordance Factors.

物种间的相互作用是生态群落形成、结构和存在的驱动力。在这些群落中，物种相互作用，争夺资源，最终塑造了地球上生物多样性的存在和分布。进化生物学的一个核心问题是这些生态群落是如何形成的，以及这些相互作用持续了多久。这项研究将为理解生态群落是否在进化时间尺度上持续存在，以及共同发生的物种在多大程度上表现出相似的遗传多样性模式提供新的工具。如果生态群落表现出强烈的共同进化历史模式，那么单个成员的灭绝可能对其他生态相关物种来说是可怕的。了解这些属性将有助于了解物种如何在更新世冰期对动态景观和气候变化做出反应，并有助于保护管理者确定需要保护的地区。本研究旨在建立系统地理一致性因子，这是一种检验生态群落共同多样化的新统计方法。这种综合将识别跨物种的共同多样化模式以及不符合这些模式的物种。系统地理一致性因子考虑了多个共存物种的物种树分布，并确定了进化枝之间共享的模式。然后用这些分支构建一个一致性树，提供一个最能代表群落多样化模式的支持值的系统发育。重要的是，这种方法将识别出优势模式的异常物种。随着将该方法开发为统计平台R的软件包，该方法将在Sarracenia alata肉食性猪笼草系统中进行演示。该系统位于地形和地质复杂的美国东南部地区，在那里许多先前的研究已经记录了新兴的生物地理模式。来自该群落的5种节肢动物的线粒体数据表明，遗传变异的结构与寄主植物相似，但从核基因组产生的初步序列数据表明，该系统的进化史更为复杂，使该系统成为使用系统地理一致性因素进行研究的理想选择。这个新工具将提高研究人员识别共同的多样化模式和影响生物多样性的进化过程的能力。

Interactions among species are driving forces behind the formation, structure and existence of ecological communities. In these communities, species interact with one another, compete for resources, and ultimately shape the existence and distribution of biodiversity on Earth. A central question of evolutionary biology is how these ecological communities came to be, and how long these interactions have persisted. This research will provide a new tool for understanding if ecological communities have persisted over evolutionary time scales, and to what extent the co-occurring species show similar patterns in their genetic diversity. If ecological communities exhibit strong patterns of a shared evolutionary history, the extinction of a single member may be dire for other ecologically associated species. Understanding these attributes will provide insight into how species responded to the dynamic landscape and climatic changes during the Pleistocene ice ages, and will help conservation managers identify regions in need of protection. This research aims to develop phylogeographic concordance factors, a novel statistical approach testing for co-diversification in an ecological community. This synthesis will identify common diversification patterns across species as well as species that do not conform to these patterns. Phylogeographic concordance factors take in species tree distributions from multiple co-occurring species, and identify patterns shared among the clades. These clades are then used to construct a concordance tree, providing a phylogeny with support values that best represents diversification patterns of the community. Importantly, this method will identify species that are outliers of a dominant pattern. Along with developing the method as a package for the statistical platform R, this approach will be demonstrated in the Sarracenia alata carnivorous pitcher plant system. This system is located in the topographically and geologically complex region of the southeastern United States, where a number of previous studies have documented emergent biogeographic patterns. Mitochondrial data from five arthropods from this community indicate that genetic variation has been structured in a similar way to the host plant, but preliminary sequence data generated from the nuclear genome implies a more complex evolutionary history for this system, making the system ideal for studies using phylogeographic concordance factors. This new tool will enhance the ability of researchers to identify shared patterns of diversification, and the evolutionary processes that have influenced biodiversity.