RUI: SG: Identification of evolutionary processes driving plant diversification on Madagascar in Megistohibiscus (Malvaceae)

RUI：SG：鉴定驱动马达加斯加 Megistohibiscus（锦葵科）植物多样化的进化过程

• 批准号: 1457589
• 负责人: Margaret Hanes
• 金额: $ 15万
• 依托单位: Eastern Michigan University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1457589&HistoricalAwards=false
• 关键词: RUI; SG; Identification; evolutionary; processes

One of the most important aims of evolutionary biology is to understand the processes responsible for speciation, and one of the best places to study species is on the island of Madagascar. The island is home to an extraordinary number of charismatic plant species and has been identified as an ideal region to investigate the processes of species diversification. This work will provide insight into how such a remarkable flora came to be. Though many ideas have been suggested as possible mechanisms for diversification on Madagascar, the evolutionary processes responsible for the island's botanical biodiversity remain poorly understood. This research will fill this gap in knowledge, test many existing hypotheses for the first time, and provide a much-needed synthesis of evolutionary process for plant diversity on the island. Powerful, new sequencing technologies and innovative analyses will be applied to a species-rich plant group, called Megistohibiscus, which has evolved exclusively on the island. Madagascar is also one of the highest priority areas for biodiversity conservation in the world and genomic data collected for this project have the potential to guide conservation decisions and help limit further losses of biodiversity. The research will provide research opportunities for female undergraduate students and underrepresented minorities at Eastern Michigan and provide important training in evolutionary genetics, systematics, bioinformatics, and conservation. One Malagasy graduate student will be involved in the research and a short course will be taught at the country's major university to facilitate international scientific exchange and address the significant shortage of trained local scientists on Madagascar.This research will synthesize findings from phylogenetic and phylogeographic investigations, information theory and ecological niche modeling to explore the mechanisms that have led to the extraordinary diversification of plants on Madagascar. Because multiple processes have likely contributed to the evolution of the flora, the work will evaluate a full range of evolutionary forces (and assess their relative contributions) in order to identify the most important processes. Speciation hypotheses will be rigorously tested for the first time in Malagasy plants and focus on a morphologically diverse, monophyletic and endemic clade (Megistohibiscus) in an important Malagasy plant family (Malvaceae; tribe Hibisceae). Analyses of genetic data collected via RAD tag Illumina sequencing will identify mechanisms promoting diversification at the species and population level. This research specifically aims to: I) Infer patterns and timing of diversification in Megistohibiscus; II) Integrate phylogenetic, geographic and temporal information to explicitly test models of speciation; III) Explore phylogeographic histories in three endemic genera (Humbertiella, Megistostegium, and Perrierophytum); and IV) Identify, rank and compare demographic processes responsible for population diversification. The resulting taxonomically complete and resolved phylogeny of Megistohibiscus will help delimit species boundaries, revise taxonomy, and provide insights into relationships of the Malagasy flora. A Malagasy Plant Evolution Working Group will be assembled to assess and strategize ways to inspire the future execution of speciation studies in other endemic plant clades to uncover comprehensive patterns of Madagascar's floristic diversity. American undergraduate students and a student from Madagascar will be trained at Eastern Michigan University, an RUI Institution, in all aspects of the research.

进化生物学最重要的目标之一是了解物种形成的过程，而研究物种的最佳地点之一是马达加斯加岛。该岛是许多极具魅力的植物物种的家园，已被确定为研究物种多样化过程的理想区域。这项工作将使我们深入了解这种非凡的植物群是如何形成的。尽管人们提出了许多关于马达加斯加岛植物多样性的可能机制的想法，但对该岛植物多样性的进化过程仍然知之甚少。这项研究将填补这一知识空白，首次验证许多现有的假设，并为岛上植物多样性的进化过程提供急需的综合。强大的新测序技术和创新分析将应用于一种物种丰富的植物群，称为巨神芙蓉，它只在岛上进化。马达加斯加也是世界上生物多样性保护最优先的地区之一，为该项目收集的基因组数据有可能指导保护决策并帮助限制生物多样性的进一步丧失。这项研究将为密歇根东部的女本科生和少数族裔提供研究机会，并在进化遗传学、系统学、生物信息学和环境保护方面提供重要的培训。一名马达加斯加的研究生将参与这项研究，并将在该国的主要大学教授一门短期课程，以促进国际科学交流，并解决马达加斯加训练有素的当地科学家严重短缺的问题。本研究将综合系统发育和系统地理调查、信息理论和生态位模型的发现，探索导致马达加斯加植物异常多样化的机制。由于多种过程可能对植物群的进化有贡献，这项工作将评估所有的进化力量（并评估它们的相对贡献），以确定最重要的过程。物种形成假说将首次在马达加斯加植物中进行严格的测试，并将重点放在一个重要的马达加斯加植物家族（malvacae; tribe Hibisceae）中形态多样、单系和特有的进化枝（Megistohibiscus）上。通过RAD标记Illumina测序收集的遗传数据分析将确定促进物种和种群水平多样化的机制。本研究的具体目的是：1)推断大戟属植物多样化的模式和时间；II)整合系统发育、地理和时间信息，明确测试物种形成模型；III)探索三个特有属（Humbertiella, Megistostegium, Perrierophytum）的系统地理历史；确定、排序和比较导致人口多样化的人口进程。由此产生的完整的分类和解决的megisstohibiscus系统发育将有助于划定物种边界，修订分类学，并提供对马达加斯加植物区系关系的见解。马达加斯加植物进化工作组将成立，以评估和制定策略，激励未来对其他特有植物分支进行物种形成研究，以揭示马达加斯加植物多样性的综合模式。美国本科生和一名来自马达加斯加的学生将在RUI机构东密歇根大学接受研究各方面的培训。