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

植物部落Senecioneae是菊科（向日葵）家族中的一大植物群，全世界约有3000种已描述的物种。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科的所有其他部落进行了大量详细的研究，却没有人试图重建这个庞大的植物群体内部的进化关系，从而在我们对最大的维管植物家族之一的理解上造成了很大的差距。拟议研究的目的是通过重建其进化史和研究夏干/冬湿栖息地（地中海气候）的起源来提高我们对Senecioneae进化成功的理解，这些栖息地是该群体许多成员生活的地方；这种气候出现在200万到600万年前，导致五大洲出现了专门的植物区系。利用生物地理和分子定年方法，估计Senecioneae的起源时间和地点，并重建从祖先地区到地中海气候地区的传播路径并确定时间。将进一步研究殖民化进入地中海地区之后的多样化模式，并推断向其他气候地区迁移的路线。因此，地中海血统的后代是否仍然局限于这些夏季干燥的地区，或者是否成为其他当代植物群的主要组成部分，将会得到确定。最终的目标是利用重建的塞尼奇亚族关系作为反映进化历史的部落新分类的基础。总的来说，这一建议的优点是通过深入了解气候变化与多样化之间的关系，更好地了解地中海气候植物的进化。此外，该项目将有助于更好地了解开花植物中最大、最多样化和最成功的家族之一的进化。这项研究的影响包括通过研究培训对学生和教师的教育作出贡献，通过增加互联网上信息的可得性对公众作出贡献，以及通过在期刊上发表和发表报告对科学界作出贡献。拟议的研究将为俄亥俄迈阿密大学的学生提供完成毕业研究要求的机会，并为研究生提供担任研究导师的机会。此外，拟议的研究将适用于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、系统发育和命名信息将被纳入“生命之树”网站，供公众访问，并链接到重要的数据库。同样，信息将提供给国际复合科联盟的网站，这是一个研究向日葵家族进化的国际科学家联盟。

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.