Environmental Heterogeneity, Local Adaptation, and Sympatric Speciation in the Hawaiian Tree, Metrosideros Polymorpha

摘要多样性早期阶段的物种为研究驱动物种形成的环境条件提供了极好的模型。高度可变的夏威夷树，多形树（'Ohi'a），就是这样一个物种，它的祖先在50万到100万年前从新西兰殖民到夏威夷群岛。Ohi'a的几个品种共同出现在火山岛上，这些火山岛的年龄范围从环境稳定的500万年前的考艾岛到仍在形成且高度异质性的大岛。因此，‘Ohi’a提供了一个理想的系统，用于研究空间和时间环境异质性与生殖隔离进化之间的关系，生殖隔离是物种形成的前兆。这项为期两年的研究将使用人工授粉、显微镜和生长室来确定品种内部和品种之间的相对杂交肥力以及在一系列条件下产生的幼苗的生存能力。所提出的工作将有助于阐明杂交树种物种形成发生的环境条件。这项工作将包括对几名本科生和一名硕士生进行进化论、野外方法和科学过程方面的培训。UH-Hilo是一所少数族裔和夏威夷原住民服务机构，招收的学生将针对代表性不足的群体。此外，通过这项拨款开发的研究项目将由P.I.修改为高年级本科生和研究生课程的讲座和实验练习。

Title: Environmental heterogeneity, local adaptation, and sympatric speciation in the Hawaiian tree, Metrosideros polymorphaAbstractSpecies in the early stages of diversification serve as excellent models for studies of the environmental conditions that drive speciation. The highly variable Hawaiian tree, Metrosideros polymorpha ('Ohi'a), is such a species, having derived from a progenitor that colonized the Hawaiian Islands from New Zealand as recently as 0.5 to 1.0 million years ago. Several of 'Ohi'a's varieties co-occur across the volcanic islands, which range in age from the environmentally stable, 5-million-year-old Kauai to the still-forming and highly heterogeneous Big Island. As such, 'Ohi'a provides an ideal system in which to examine the relationship between spatial and temporal environmental heterogeneity and the evolution of reproductive isolation, a precursor to speciation. This two-year study will use hand-pollinations, microscopy, and growth chambers to determine the relative cross-fertility within and between varieties and the viability of the resulting seedlings under a range of conditions. The proposed work will help to illuminate the environmental conditions under which speciation in out crossed tree species will occur. The work will involve the training of several undergraduate students and one M.S. student in evolutionary theory, field methods, and the scientific process. Recruitment of students will target under-represented groups at UH-Hilo, a Minority and Native Hawaiian-serving Institution. Further, the research projects developed through this grant will be modified by the P.I. into lecture and laboratory exercises in upper-undergraduate and graduate courses.