DISSERTATION RESEARCH: Asymmetric character displacement in evolutionary-novel Anolis lizards.

这项工作将为进化如何导致相似物种的共存提供新的理解，这些物种为资源而激烈竞争。当物种竞争同一资源时，较弱的竞争者可以从群落中被淘汰。尽管如此，还是有许多群落包含竞争物种。一种假说认为，相互竞争的物种分化是为了减少竞争，这种现象被称为“特征置换”。这项工作的重点是已经引入佛罗里达州南部的密切相关的蜥蜴物种。它们最近的共存为研究物种如何应对新的竞争，以及每个物种的哪些特征因此而分化提供了一个机会。观察到的生态和形态的变化可能最终促成了它们的长期共存。本研究的结果将有助于更好地理解性状位移在生物多样性起源和维持中的作用。该项目还创建了一个框架，用于向学生和公众传授增强生物多样性的过程。这一框架将通过一个生态俱乐部和一个信息网页，以及让本科生参与研究来实施。种群的两个非本地的蜥蜴，没有事先的进化相互作用，将研究量化的进展特征位移。这些物种，古巴棕色变色鹦鹉（Anolis sagrei）和波多黎各冠色变色鹦鹉（A. cristatellus），在生态和形态上是相似的。在整个迈阿密，它们存在于多个空间独立的群落中，这些群落要么由两种物种（同域种群）组成，要么只有一种物种（异域种群）。这些群落类似于适应性辐射的早期阶段，在异种中形成的生态形态相似的物种由于种间竞争而接触并适应性地分化。该项目将调查这两个物种之间的生态关系，以验证以下假设：（H1）在彼此存在的情况下，两个物种将在资源利用方面出现分歧，以减少种间的相互作用。这一假设将通过对这两个物种的生态学和行为的详细分析来验证，这些生态学和行为将在异域和同域种群的多个复制中进行。（H2）资源利用的差异导致两种物种表型的变化？这就是字符置换的过程。这一假设将通过在种群中对两个物种进行详细的表型评估来验证。（H3）表型性状的变化是可遗传的。这一假设将通过实验室育种实验测量性状遗传力来验证。这个案例研究将提供一个更详细的理解竞争在进化分化中的作用。

This work will provide new understanding of how evolution can result in the coexistence of similar species that compete strongly for resources. When species compete for the same resource the weaker competitor can be eliminated from the community. Nonetheless, there are many communities that contain competing species. One hypothesis is that competing species diverge so as to reduce competition, a phenomenon known as character displacement. This work focuses on closely related lizard species that have been introduced to southern Florida. Their recent co-occurrence provides an opportunity to study how species respond to novel competition, and what traits in each species diverge as a result. Observed shifts in both ecology and morphology may ultimately contribute to their long-term coexistence. The result of this study will be a better understanding of the role of character displacement in the origin and maintenance of biodiversity. This project also creates a framework for teaching students and the public about the processes that enhance biodiversity. This framework will be implemented via an Ecology Club and an information webpage, as well as by engaging undergraduates in the research.Populations of two non-native Anolis lizards, that have had no prior evolutionary interactions, will be studied to quantify the progression of character displacement. These species, the Cuban brown anole (Anolis sagrei) and the Puerto Rican crested anole (A. cristatellus), are ecologically and morphologically similar. Throughout Miami FL, they exist in multiple spatially-independent communities that consist of either both species (sympatric populations) or only one species (allopatric populations). These communities are analogous to the early stages of adaptive radiation, whereby ecomorphologically similar species that have speciated in allopatry come into contact and adaptively diverge as a result of interspecific competition. The project will investigate the ecological relationship between these two species to test the following hypotheses: (H1) In the presence of each other, both species will experience a divergence in resource use to minimize interspecific interactions. This hypothesis will be tested through detailed analyses of the ecology and behavior of both species across multiple replicates of both allopatric and sympatric populations. (H2) Divergence in resource use leads to changes in the phenotype of both species ? this is the process of character displacement. This hypothesis will be tested by detailed phenotypic assessments of both species across the populations. (H3) Shifts in phenotypic traits are heritable. This hypothesis will be tested by measuring trait heritability with laboratory breeding experiments. Taken together this case study will provide a more detailed understanding of the role of competition in evolutionary divergence.