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.

豆类是开花植物的第三大家族。这些在经济和生态意义上有意义的植物的规模从微小的沙漠草药到巨大的雨林树。尽管最近的研究阐明了家庭主要血统之间的关系，但对近20,000种的许多物种中的许多知识却一无所知，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建模来解决大型和广泛的热带豆类群体之间的进化关系，并推断出对新环境的作用（如果有的话）在这些物种的多元化中起着什么作用。 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将来的比较研究提供一个框架，并增强我们对豆类家族的整体演变的理解。 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.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，非常浅的进化问题，但其应用于物种水平的系统发育学，尤其是在植物中，仍然有限。但是，在物种层面上，这些新技术是解决以前棘手的关系的最大希望。此外，当与生态利基建模和地理范围数据结合使用时，这些方法能够产生良好的系统发育，使研究人员能够研究物种形成机制以及利基保守主义在产生观察到的多样性模式中的作用。例如，如果同种姐妹物种沿环境轴始终隔离，那么生态介导的选择可能在物种中起作用，而同种异体姐妹物种在非生物壁球空间中持续相同或几乎相同，那么生态差异就不是主要因素驱动因素驱动。 为了解决这个问题，研究人员将：1）进行现场工作并参观巴西的赫巴里亚（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）使用针对序列捕获技术生成的数据重建了良好的物种水平的系统发育；和3）使用生态生态位建模和分布数据来表征组成物种的非生物利基市场。这些数据的分析将为Cynometra和Maniltoa的进化和生物地理历史以及推动这些过程的机制提供更精确的了解。