Phylogenetics and Biogeography of Subtribe Butiinae (Cocoeae, Palmae)

0212779 Hahn和NoblickDr.哥伦比亚大学的William Hahn和蒙哥马利植物中心的Larry Noblick博士正在结合他们的分子和形态学专业知识来研究椰子（Cocos nucifera）及其分类学亲属的系统学和进化。椰子是三种最具经济价值的棕榈树之一，但其起源和关系却知之甚少。棕榈族Cocoeae由22个属（包括椰子）组成，其中两个属在马达加斯加，一个属在南非，椰子在东南亚和太平洋，其余18个属在新大陆。由于在过去几十年中已经提出了几种不同的分类法，因此需要对部落的现有分类法进行严格的重新评估。需要估计进化关系来解决这些分类学上的争论以及椰子地理起源的争议。该物种似乎原产于东南亚和南太平洋，但其所有近亲都在非洲，马达加斯加或新大陆发现。由于其通过漂浮扩散的显著能力，自然和人为传播都被认为可以解释其起源和目前的分布。提出了两种主要的地理情景：从马达加斯加/非洲跨越印度洋或从美洲跨越太平洋。为了在这些相互竞争的植物地理学假说之间做出选择，必须对椰子与其他棕榈树的关系进行明确的研究。哈恩博士和诺布里克博士的研究使用现代分子和形态学系统发育方法来重建椰子和相关物种的进化历史，并开发了一个分子钟框架，用于评估多样化的速度。形态学和分子数据将被积累，以估计形成可可族的22个属之间的进化关系，预计将改进属级的界限和分类。分子钟（基于多个核基因和质体基因）将被用来确定这个部落的分类群之间的分歧事件，并估计椰子的起源时间。基于这些结果，可以进行替代分类学和地理学假设的测试，从而更好地了解经济上重要的作物物种的进化过程。研究生和本科生都将在这个项目中得到支持，并将在野外，植物园，植物标本馆，计算机和分子进化技术方面得到指导。这些研究的结果也将在佛罗里达迈阿密的蒙哥马利植物中心的公共教育项目中提出。

0212779Hahn and NoblickDr. William Hahn of Columbia University and Dr. Larry Noblick of the Montgomery Botanical Center are combining their molecular and morphological expertise to study the systematics and evolution of the coconut, Cocos nucifera, and its taxonomic relatives. The coconut is one of the three most economically important species of palms, yet its origins and relationships are poorly understood. The palm tribe Cocoeae consists of 22 genera (including the coconut) with two genera in Madagascar, one genus in South Africa, the coconut in Southeast Asia and the Pacific, and the remaining 18 genera in the New World. Available taxonomies for the tribe are in need of critical reevaluation as several different taxonomies have been proposed over the past few decades. An estimate of evolutionary relationships is needed to resolve these taxonomic debates as well as controversy over the geographic origin of the coconut. The species appears to be native to Southeast Asia and the South Pacific, but all of its close relatives are found in Africa, Madagascar, or the New World. Because of its remarkable ability to disperse by floating, both natural and human-mediated dispersal have been suggested to explain its origins and current distribution. Two primary geographic scenarios have been proposed: from Madagascar/Africa across the Indian Ocean or from the Americas across the Pacific Ocean. An explicit examination of the coconut's relationships to other palms is necessary to choose between these competing biogeographic hypotheses.Dr. Hahn and Dr. Noblicks's research uses modern molecular and morphological phylogenetic methods to reconstruct the evolutionary history of the coconut and related species and to develop a molecular clock framework for the evaluation of rates of diversification. Morphological and molecular data will be accumulated to estimate evolutionary relationships among the 22 genera that form tribe Cocoeae, with anticipated improvements to genus-level circumscription and classification. Molecular clocks (based on multiple nuclear and plastid genes) will be used to date divergence events among the taxa in this tribe and to estimate the time of origin for the coconut. Based on these results, tests of alternative taxonomic and biogeographic hypotheses can be conducted, leading to a better understanding of the evolutionary process in an economically important crop species. Both graduate and undergraduate students will be supported in this project and will be instructed in field, botanical garden, herbarium, computer, and molecular evolutionary techniques. Results of these studies will also be presented in the public education programs of the Montgomery Botanical Center in Miami, Florida.