Dissertation Research: Systematics, biogeography and taxonomy of the pantropical legume genus Cynometra

论文研究：泛热带豆科植物Cynometra 的系统学、生物地理学和分类学

• 批准号: 1501199
• 负责人: Patrick Herendeen
• 金额: $ 2.01万
• 依托单位: Chicago Horticultural Society
• 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 2017-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501199&HistoricalAwards=false
• 关键词: Dissertation; Research; Systematics; biogeography; taxonomy

Legumes are the third largest family of flowering plants. These economically and ecologically significant plants range in size from tiny desert herbs to giant rainforest trees. While recent research has elucidated relationships among the major lineages in the family, little is known about many of the nearly 20,000 species, especially the processes that generate this diversity. This study will use recently developed 'next generation' DNA sequencing methods and statistical computer modeling to resolve the evolutionary relationships among a large and widespread group of tropical legumes and to infer what role, if any, adaptation to new environments has played in the diversification of these species. Given their wide distribution and ecological diversity, understanding the relationships among these species will provide a framework for future comparative studies and enhance our understanding of the overall evolution of the legume family. The project will also include a significant training component to expose undergraduates in STEM fields to the latest tools and analytic methods.This study will combine phylogenomics, ecological niche modeling, and information from the fossil record to elucidate the relationships among the species of the tropical genera Cynometra and Maniltoa and will investigate the role niche conservatism plays in biogeography and speciation mechanisms. Next generation sequencing is revolutionizing the practice of systematics, biogeography, and evolutionary biology. While the technology has been applied to both very deep and very shallow evolutionary questions, its application to species level phylogenetics, particularly in plants, remains limited. However, it is at the species level that these new techniques hold the greatest promise to resolve previously intractable relationships. In addition, when combined with ecological niche modeling and geographic range data, the well resolved phylogenies these methods are capable of producing allow researchers to study speciation mechanisms and the role of niche conservatism in generating observed patterns of diversity. If, for example, allopatric sister species consistently segregate along environmental axes, then ecologically mediated selection may have a role in speciation, whereas if allopatric sister species are consistently identical or nearly identical in abiotic niche space, then ecological divergence is not a major factor driving speciation. To address this question, the researchers will: 1) conduct field work and visit herbaria in Brazil (the center of diversity for the genus) to better characterize diversity and distributions of Brazilian species; 2) reconstruct a well resolved species level phylogeny using data generated with targeted sequence capture techniques; and 3) characterize the abiotic niche of the constituent species using ecological niche modeling and distribution data. Analyses of these data will provide a much more precise understanding of evolutionary and biogeographic history of Cynometra and Maniltoa and the mechanisms driving these processes.

豆科植物是第三大开花植物科。这些具有经济和生态意义的植物大小不一，从微小的沙漠草本到巨大的雨林树木。虽然最近的研究阐明了该科主要谱系之间的关系，但人们对近 20,000 个物种中的许多物种知之甚少，尤其是产生这种多样性的过程。这项研究将使用最近开发的“下一代”DNA测序方法和统计计算机模型来解决大量广泛分布的热带豆科植物之间的进化关系，并推断对新环境的适应在物种多样化中发挥了什么作用（如果有的话）。这些物种。 鉴于它们的广泛分布和生态多样性，了解这些物种之间的关系将为未来的比较研究提供框架，并增强我们对豆科植物整体进化的理解。该项目还将包括一个重要的培训部分，让 STEM 领域的本科生接触最新的工具和分析方法。这项研究将结合系统发育组学、生态位模型和化石记录信息来阐明热带属物种之间的关系Cynometra 和 Maniltoa 将研究生态位保守主义在生物地理学和物种形成机制中的作用。下一代测序正在彻底改变系统学、生物地理学和进化生物学的实践。虽然该技术已应用于非常深和非常浅的进化问题，但其在物种水平系统发育学，特别是在植物中的应用仍然有限。然而，正是在物种层面，这些新技术最有希望解决以前棘手的关系。此外，当与生态位模型和地理范围数据相结合时，这些方法能够产生良好解析的系统发育，使研究人员能够研究物种形成机制以及生态位保守主义在生成观察到的多样性模式中的作用。例如，如果异域姐妹物种始终沿着环境轴分离，那么生态介导的选择可能在物种形成中发挥作用，而如果异域姐妹物种在非生物生态位空间中始终相同或几乎相同，那么生态趋异就不是驱动的主要因素物种形成。 为了解决这个问题，研究人员将：1）进行实地工作并参观巴西的植物标本馆（该属的多样性中心），以更好地描述巴西物种的多样性和分布； 2) 使用目标序列捕获技术生成的数据重建良好解析的物种水平系统发育； 3）利用生态位模型和分布数据来描述组成物种的非生物生态位。对这些数据的分析将使人们更准确地了解食蟹猴和马尼托亚的进化和生物地理历史以及驱动这些过程的机制。