Testing Adaptive Radiation Theory in Penstemon (Plantaginaceae)

许多动物和植物群体非常多样化，物种丰富，但与一类没有多样性和物种贫乏的生物密切相关。多样化可以是一个缓慢的过程，也可以是一个快速的过程，为什么一些群体变得非常多样化，有数百个物种，而另一些群体只有几个物种，这是一个动态变化的环境下特别相关的研究领域。适应性辐射理论预测，由于对生态机会的适应，物种形成率会增加，并且物种形成率最初很高，但随着生态位的填满或灭绝率的增加而降低。一些标志性的动物群体已经成为适应性辐射理论的试验场，但很少有植物研究关注于测试该理论的预测。大盆草（车前草科）是北美最大的原生植物属，有近300种，是自更新世以来经历快速多样化的一个极好的例子。在更新世，气候条件的变化导致覆盖北半球大部分地区的巨大冰盖融化，这种植物迅速多样化，有数百种。本研究将研究环境变化对生物的影响，以及生物如何通过物种形成来适应气候生态位。该项目将为研究生提供系统学和生物信息学培训，并将为公众、科学家和教育工作者提供开源生物信息学工具和基于网络的生物多样性数据。该项目将产生下一代测序数据，并开发新的物种树方法来测试Penstemon的适应性辐射理论。该项目将从多个基因座生成下一代靶向扩增子测序数据，然而处理与收集基因组数据相关的大量数据一直是一项技术挑战。为了解决这个问题，该项目将开发新的分析方法来处理具有许多分类群和大量数据的数据集，该项目将开发基于聚结的方法来从多位点数据估计物种树。推断出的物种树将用于检查整个属的物种多样化率，特别是阐明进化枝是否表现出与适应性辐射理论预测的模式一致。将分析形态特征、生态栖息地、种子萌发要求、杂交发生率和地理数据，以确定是否存在关键的创新和/或生态机会，这些创新和/或生态机会可以解释整个属的物种形成率差异。此外，还将开发新的分析方法，以检测具有快速多样化速率的属的杂交模式。

Many groups of animals and plants are very diverse and species rich but are closely related to a group of organisms that are not diverse and are species poor. Diversification can be a slow process or a rapid one, and the dynamics of why some groups become very diverse with hundreds of species, while others have just a few is an especially relevant field of study given a dynamically changing environment. Adaptive radiation theory predicts an increase in speciation rates resulting from adaptations in response to ecological opportunity, and that speciation rates are initially high, but decrease as ecological niches fill or extinction rates increase. Several iconic groups of animals have served as testing grounds for adaptive radiation theory, but few plant studies have focused on testing predictions of the theory. Penstemon (Plantaginaceae) is the largest plant genus native to North America, with nearly 300 species, and is an excellent example of a group that had undergone rapid diversification since the Pleistocene. Penstemon, diversified rapidly, with hundreds of species, during the Pleistocene when changing climatic conditions resulted in the melting of massive ice sheets covering much of the northern hemisphere. This research will study the effect of changing environment on organisms and how they adapt to climatic niches through speciation. The project will integrate systematics and bioinformatics training for graduate students and will result in open-source bioinformatics tools and web-based biodiversity data for the general public, scientists, and educators.This project will generate next-generation sequencing data and develop novel species trees methods to test adaptive radiation theory in Penstemon. The project will generate next-generation targeted amplicon sequencing data from multiple loci, however handling the large volumes of data associated with collecting genomic data has been a technological challenge. To solve this issue the project will develop new methods of analyses to handle data sets with many taxa and large amounts of data and the project will develop a coalescent-based approach for estimating a species tree from multi-locus data. The species tree inferred will be used to examine rates of species diversification across the genus, specifically elucidating whether clades exhibit patterns consistent with those predicted by adaptive radiation theory. Morphological characters, ecological habitats, seed germination requirements, incidence of hybridization, and geographical data will be analyzed to determine if there are key innovations and/or ecological opportunities that may explain differences in speciation rates across the genus. Additionally, new methods of analyses will be developed for detecting patterns of hybridization in a genus that has a rapid rate of diversification.