US-South Africa Dissertation Enhancement: The Evolution of Long-Tongued Fly Pollinators (Diptera: Tabanidae)

0138288M。桑德森这篇论文增强拨款资助了美国研究生谢拉·森田女士，她在加州大学戴维斯分校进化和生态学系的迈克尔·桑德森教授的指导下，在南非进行了一项关于长舌马蝇(双翅目：蝇科)和它们授粉的深喉花的共同进化的研究。共同进化的研究可以提供关于物种相互作用在物种形成中的重要性的知识，但当今物种之间的联系可能不能反映它们过去的关系。双翅目：蚊科是研究共同进化的理想系统，因为它们异常长的口器被认为与它们赖以生存的花的形态特征是一致的，而且已经证明，这些马蝇与南非Fynbos地区特有植物区系的适合性密切相关。但这组马蝇的生物地理分布与目前对历史生物地理学的理解所提供的预测生物分布不符。森田女士假设：1)南非以蜜为食的蝠科与它们授粉的植物是共同进化的，2)取血是Philolichini部落中雌性长舌马蝇的祖先。她还试图了解目前对马蝇的分类是否正确地代表了它们的进化关系。通过独特的系统发育方法和种群水平的研究相结合，森田女士将首先研究植物和传粉者的系统发育，然后她将分析鼻子长度和花蜜短刺长度的共同进化，以了解这一类蝗科的进化关系。学生将使用从实地收集的样本和机构样本中获得的数据。纳塔尔大学植物学与动物学学院的史蒂文·约翰逊博士是这一系统的授粉生态学和植物系统学方面的知名权威，他将为森田女士提供这个项目的指导。这项研究的结果有望促进对动物和植物如何共同进化和获得新的取食行为的现有认识。该项目还将支持一名优秀研究生在职业生涯早期的一次国际研究经历。国际科学与工程办公室和环境生物系共同资助这一项目。

0138288M. SandersonThis dissertation enhancement grant supports a US graduate student, Ms. Shelah Morita, working under the guidance of Professor Michael Sanderson, in the Section of Evolution and Ecology at the University of California-Davis, to conduct a study in South Africa on the coevolution of long-tongued horse flies (Diptera: Tabanidae) and the deep-throated flowers that they pollinate.The study of coevolution can provide knowledge about the importance of species interactions in speciation, but present day associations between species may not reflect their past relationships. Diptera: Tabanidae is an ideal system for studying coevolution because their unusually long mouthparts are thought to covary with the morphological features of the flowers on which they feed, and it has already been demonstrated that these horse flies are closely tied to the fitness of the endemic flora of the South African fynbos region. But the biogeographical distribution of this group of horse flies does not match the predicted biotic distribution provided by the current understanding of historical biogeography. Ms. Morita hypotheses that: 1) Nectar-feeding Tabanidae in South Africa have coevolved with the plants they pollinate, and 2) Blood feeding is ancestral in female long-tongued horse flies within the tribe Philolichini. She also seeks to learn if the current classification of horse flies correctly represents their evolutionary relationships. Through a unique combination of phylogenetic approach and population-level studies, Ms. Morita will first study the phylogenies of both plants and pollinators, after which she will analyze the coevolution of proboscis length and nectar spur length in order to understand the evolutionary relationships within this group of Tabanidae. The student will use data obtained from field collected samples and institutional specimens. Dr. Steven Johnson, with the School of Botany and Zoology at the University of Natal, is a noted authority on the pollination ecology and plant systematics of this system, and he will provide guidance on this project to Ms. Morita. The results of this study are expected to advance the current knowledge on how animals and plants coevolve and new feeding behaviors are acquired. This project will also support an international research experience very early in the career of an outstanding graduate student.The Office of International Science and Engineering and the Division of Environmental Biology jointly fund this project.