Late Tertiary Climatic Changes and the Evolutionary Success of Tribe Senecioneae (Asteraceae): A Phylogenetic Approach

晚第三纪气候变化和千里光族（菊科）的进化成功：系统发育方法

• 批准号: 0542238
• 负责人: Linda Watson
• 金额: $ 30.19万
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-15 至 2009-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0542238&HistoricalAwards=false
• 关键词: Late; Tertiary; Climatic; Changes; Evolutionary

The plant tribe Senecioneae is a large group of plants in the Asteraceae (Sunflower) family, with approximately 3000 described species worldwide. It has an almost cosmopolitan distribution and harbors enormous diversity in morphological adaptations. Yet there has been no attempt to reconstruct the evolutionary relationships within this enormous plant group despite the numerous and detailed studies on the Asteraceae as a whole and for all other tribes in this family, thereby creating a large gap in our understanding of one of the largest families of vascular plants. The aim of the proposed research is to improve our understanding of the evolutionary success of Senecioneae by reconstructing its evolutionary history and by examining the origin of summer-dry / winter-wet habitats (mediterranean climates) in which so many members of this group live; such climates appeared between 2 and 6 million years ago and resulted in regions with specialized floras on five continents. Utilizing biogeographic and molecular dating methods, the time and place of origin for the Senecioneae will be estimated, and dispersal pathways leading from ancestral area(s) into regions with Mediterranean climates will be reconstructed and dated. The patterns of diversification that subsequently followed colonization into Mediterranean regions will be further examined and routes of migration into areas with other climates will be inferred. Thus, it will be determined if the descendents of Mediterranean lineages remained confined to these summer-dry areas, or alternatively, became main elements of other contemporary floras. A final goal is to use the reconstructed relationships of Senecioneae as a basis for a new classification for the tribe that reflects evolutionary history. The merits of this proposal will be a better understanding of the evolution of Mediterranean-climate plants, in general, by providing insight into the relationship between climate change and diversification. Furthermore, this project will contribute to a better understanding of the evolution of one of the largest, most diverse, and successful families of flowering plants.The impacts of this research include contributions to the education of students and teachers through research training, to the general public through the increased availability of information on the Internet, as well as to the scientific community through publication in journals and presentations. The proposed research will give opportunities for Miami University of Ohio students to complete their research requirements for graduation, and opportunities for graduate students to serve as research mentors. In addition, the proposed research will be available to students who apply to the University's Summer Scholars Program and to in-service primary and secondary school teachers in the Masters of Teaching Program. Photographs, descriptions, phylogenies, and nomenclatural information will be incorporated into the Tree of Life website for access by the general public with links to important databases. Similarly, information will be provided for the website of The International Compositae Alliance, an international consortium of scientists studying the evolution of the sunflower family.

千里光族植物是菊科(向日葵)中的一大类植物，全世界约有3000种已描述的植物。它几乎分布在世界各地，在形态适应方面具有巨大的多样性。然而，尽管对整个菊科和这个家族中所有其他部落进行了大量和详细的研究，但还没有人试图重建这个庞大的植物群内的进化关系，从而造成了我们对维管束植物中最大的一个家族之一的认识上的巨大差距。拟议研究的目的是通过重建千里光科植物的进化史和研究该类群中许多成员所生活的夏季-干燥/冬季-潮湿生境(地中海气候)的起源，来提高我们对千里光亚科进化成功的理解；这种气候出现在200万至600万年前，导致在五大洲有专门的植物区系。利用生物地理和分子测年方法，将估计千里光的起源时间和地点，并将重建从祖先地区(S)到地中海气候地区的扩散路径。将进一步审查随后殖民到地中海区域之后的多样化模式，并推断移民到其他气候地区的路线。因此，将确定地中海血统的后裔是否仍然局限在这些夏季干燥的地区，或者成为其他当代植物群的主要成分。最终目标是利用重建的千里光亚族关系作为反映进化史的部落新分类的基础。这项提议的优点是通过洞察气候变化和多样性之间的关系，更好地了解地中海气候植物的总体演变。此外，该项目将有助于更好地了解最大、最多样化和最成功的开花植物家族之一的进化。这项研究的影响包括通过研究培训对学生和教师的教育做出贡献，通过在互联网上更多地获得信息对公众做出贡献，以及通过在期刊和演示文稿上发表对科学界的贡献。这项拟议的研究将为俄亥俄迈阿密大学的学生提供完成毕业前研究要求的机会，并为研究生提供担任研究导师的机会。此外，拟议的研究将提供给申请大学暑期学者计划的学生和教学硕士计划的在职中小学教师。照片、描述、系统发展史和命名信息将被纳入生命树网站，供公众访问，并提供重要数据库的链接。同样，还将为国际菊科联盟网站提供信息，这是一个研究向日葵家族进化的国际科学家联盟。