Collaborative Research: Evolution and Systematics of the Neotropical Plant Clade of Schefflera (Araliaceae)

植物学家的一个主要目标是描述和命名地球上发现的大量植物物种，并了解植物是如何、何时和在哪里进化的。对于物种数量非常多的群体来说，这尤其具有挑战性，特别是当他们很难观察到的时候，因为他们生长在很难到达的地方。热带树属的物种很多，属于最未被研究的植物类群，这在我们的知识中造成了很大的差距。为了克服这一差距，需要一种高效和有效的战略来发现、描述、理解和保护世界生物多样性的这一大而重要的部分。这项研究项目将开发一种简化的策略，以热带美洲常春藤属(常春藤属，五加科)为模型组。在这片辽阔的地区，特别是在安第斯山脉北部的山区，生活着400多种舍弗勒氏菌。其中许多物种只被科学家见过一次或几次，几乎一半还没有科学名称。此外，几乎没有工具可以识别和识别这些具有生态重要性的植物，我们几乎不知道它们是如何进化成这么多不同的形式，或者它们如何能够适应广泛的栖息地。这项研究的战略包括在四个安第斯国家(玻利维亚、哥伦比亚、厄瓜多尔和秘鲁)的实地工作，旨在提高我们对这些进化过程的理解。它还将专注于识别和命名在有限数量的地方出现的、最有可能灭绝(主要是由于热带砍伐森林)的物种，以便它们能够成为保护努力的目标。该项目产生的信息将在网上向科学界内外的广泛用户提供。为了帮助培养下一代植物系统学家，12名本科生将有机会通过密苏里州和纽约植物园的两个为期6周的暑期实习项目来了解这一重要但被低估的植物学分支，另外12名植物学或生物学的高级学生将参加热带野外植物学项目，加入该项目的科学家们在南美洲的实地工作中获得实践经验。该研究将涉及利用基于DNA的证据来构建安第斯雪佛兰物种的系统发育图，利用最新的技术进步，特别是DNA测序的高通量方法。系统发育将提供对这400个物种主要谱系的更多了解，这反过来将为它们的分类和命名提供一个框架，并为理解它们的进化和地理关系提供框架。对最有可能受到威胁的物种的保护状况进行评估的简化“绿色清单”方法，将为命名和保护Schefflera的新的和稀有的安第斯成员提供优先事项。密集的植物标本馆研究将提供地理、形态和分子数据来源，并将指导安第斯山脉中部和北部国家的实地工作，目标是仍未采样的物种最集中的地点，并侧重于厄瓜多尔南部和秘鲁北部的地区，这些地区的物种似乎经历了特殊的多样化。时间确定的系统发育将用于探索生物地理情景，并测试形态、生态、地理和进化史之间的相关性，为安第斯山脉植物多样性的演化提供洞察力。这些研究将与当地植物学家和将进行实地工作的四个南美洲国家的学生合作进行。这将促进一个长期的国际研究人员网络，能够维持充分记录和了解热带安第斯山脉谢弗莱拉巨大多样性的长期目标。

A major goal of botanists is to describe and name the vast diversity of plant species found on our planet and to understand how, when, and where plants evolved. This is particularly challenging for groups with very large numbers of species, especially when they are difficult to observe because they grow in hard to reach places. Tropical tree genera with many species are among the most under-studied plant groups, creating a significant gap in our knowledge. To overcome this gap, an efficient and effective strategy is needed to discover, describe, understand and conserve this large and important part of the world's biodiversity. This research project will develop a streamlined strategy, using the genus Schefflera (a member of the ivy family, Araliaceae) in tropical America as a model group. More than 400 species of Schefflera occur in this vast region, especially in the very mountainous areas of the northern Andes. Many of these species have only been seen by scientists once or a few times, and almost half do not yet have scientific names. Moreover, very few tools are available to recognize and identify these ecologically important plants, and we know almost nothing about how they evolved into so many different forms, or how they were able to adapt to the wide range of habitats. The strategy of this study, which includes field work in four Andean countries (Bolivia, Colombia, Ecuador and Peru), aims to improve our understanding of these evolutionary processes. It will also focus on identifying and naming the species that occur in a limited number of places and are most threatened with extinction (mostly by tropical deforestation) so that they can be targeted by conservation efforts. The information generated by the project will be made available on-line to a wide range of users, both within and beyond the scientific community. To help develop the next generation of plant systematists, 12 undergraduate students will be given an opportunity to learn about this important yet under-appreciated branch of botany through two 6-week summer internship programs at the Missouri and New York Botanical Gardens, and 12 more advanced students in botany or biology will participate in a tropical field botany program, joining the project scientists to gain hands-on experience during field work in South America.The research will involve constructing phylogenies for the species of Andean Schefflera using DNA-based evidence, taking advantage of recent advances in technology, especially high-throughput approaches to DNA sequencing. The phylogenies will provide a greater understanding of the major lineages of these 400+ species, which in turn will provide a framework for classifying and naming them, and for understanding their evolutionary and geographic relationships. A streamlined 'green-listing' approach to assessing conservation status of the species that are most likely to be threatened will inform priorities for naming and conserving new and rare Andean members of Schefflera. Intensive herbarium studies will provide sources of geographic, morphological, and molecular data, and will guide field work in the countries of the central and northern Andes, targeting sites with the highest concentration of species that remain unsampled, and focusing on areas in southern Ecuador and northern Peru where the group appears to have undergone exceptional diversification. Time-dated phylogenies will be used to explore biogeographic scenarios and to test for correlations among morphology, ecology, geography and evolutionary history, providing insights into the evolution of plant diversity in the Andes. These studies will be conducted with the collaboration of local botanists and students from each of the four South American countries where field work will be done. This will promote a long-term network of international researchers capable of sustaining the long-term goals of fully documenting and understanding the tremendous diversity of Schefflera in the tropical Andes.