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

0138288米。美国加州大学戴维斯分校进化与生态学系研究生Shelah Morita女士在Michael Sanderson教授的指导下，在南非进行了一项关于长舌马蝇（双翅目：虻科）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，但是现在物种之间的联系可能不能反映它们过去的关系。双翅目：虻科是研究共同进化的理想系统，因为它们异乎寻常的长口器被认为与它们赖以生存的花朵的形态特征相一致，而且已经证明这些马蝇与南非芬波斯地区特有植物群的适应性密切相关。但是，这群马蝇的生物地理分布与目前历史生物地理学的认识所预测的生物分布并不相符。森田女士假设：1)南非以花蜜为食的Tabanidae与它们授粉的植物共同进化；2)吸血的祖先是Philolichini部落中的雌性长舌马蝇。她还试图了解目前马蝇的分类是否正确地代表了它们的进化关系。通过系统发育方法和种群水平研究的独特结合，森田女士将首先研究植物和传粉媒介的系统发育，之后她将分析吻长和花蜜刺长度的共同进化，以了解Tabanidae组内的进化关系。学生将使用从现场收集的样本和机构标本中获得的数据。纳塔尔大学植物与动物学院的Steven Johnson博士是该系统传粉生态学和植物系统学方面的知名权威，他将为Morita女士提供该项目的指导。本研究的结果有望推动目前对动物和植物如何共同进化和获得新的摄食行为的认识。该项目还将支持优秀研究生在职业生涯的早期获得国际研究经验。国际科学与工程办公室和环境生物学部共同资助了这个项目。

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.