Dimensions: Collaborative Research: Biotic and abiotic drivers of Neotropical plant speciation

植物是陆地生物多样性的基础，中美洲和南美洲的森林是世界上植物种类最多的地方。经过很长一段时间，植物的多样性是由物种形成产生的，这是一个物种变成两个物种的复杂过程。这个项目将检验关于热带森林中物种形成如何发生的想法。它还将大大增加植物如何应对不同环境的基本知识，以及它们如何与授粉和吃叶子的昆虫相互作用。许多本科生和研究生，特别是那些来自科学界代表性不足群体的学生，将参与该项目，获得研究经验和职业培训。该小组将努力提高生物多样性科学的国际能力，方法是帮助在拉丁美洲开设实地课程，让每个热带实地地点的当地研究助理参与其中，并在哥斯达黎加组织一次国际研究研讨会。最后，调查人员将向公众广泛传播他们的经验和科学发现。研究结果将有助于指导热带森林的保护和管理，热带森林由于人类的影响正在迅速变化。关于热带高物种形成率，提出了两种进化假说。首先，由于热带气候全年相对稳定，生物可能无法进化出适应大范围气候的能力，因此可能不会广泛扩散。然后，当地种群将与它们的亲缘物种隔离，并逐渐成为新物种。另外，植物与其他生物（如传粉者和食草动物）之间的相互作用可能因地而异，因此，适应一个生物群落的种群在传播到另一个群落时，生长和繁殖会很差。这样，不同地点的植物就有可能通过自然选择而成为不同的物种。这项研究使用哥斯达黎加和巴拿马的单子叶木香属的螺旋姜来测试这些关于热带物种形成的假设。螺旋姜的栖息地范围很广，从低地到山地森林，从茂密的林下到森林边缘，具有不同的温度、水和土壤条件。它们与许多不同的兰花蜂和蜂鸟传粉者，以嫩叶为食的高度专业化的甲虫，以及保护食草动物免受花蜜侵害的蚂蚁相互作用。这项工作整合了系统发育研究、大规模观察方法、重点领域实验（相互移植和直接操纵相互作用的生物体和非生物因素）和遗传作图。它将决定植物如何与传粉者、食草动物、蚂蚁保护器和地理范围内的气候条件相互作用和适应。它将评估物种形成是否由性状和基因引起，这些性状和基因在一种环境中有积极影响，而在另一种环境中有消极影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plants are the foundation for terrestrial biodiversity, and the forests of Central and South America are home to more types of plants than anywhere else in the world. Over very long time periods, this diversity of plants is produced by speciation, the complicated process whereby one species becomes two. This project will test ideas about how speciation happens in tropical forests. It will also greatly increase basic knowledge of how plants cope with different environments and how they interact with insects that pollinate their flowers and eat their leaves. Many undergraduate and graduate students, especially those from underrepresented groups in science, will participate in the project, gaining research experience and career training. The team will work to increase international capacity in biodiversity science by helping with field courses in Latin America, involving local research assistants at each tropical field site, and organizing an international research symposium in Costa Rica. Finally, investigators will broadly communicate their experiences and scientific findings to the general public. Results will help guide conservation and management of tropical forests, which are rapidly changing due to human influences.Two evolutionary hypotheses for high tropical speciation rates have been proposed. First, because tropical climates are relatively stable year-round, organisms may not evolve the ability to tolerate a wide range of climates and therefore may not disperse widely. Local populations will then become isolated from their relatives and gradually become new species. Alternatively, interactions between plants and other organisms, such as pollinators and herbivores, may vary from place to place, such that a population adapted to one biological community will grow and reproduce poorly when it spreads to another community. In this way, there may be natural selection for plants in different locations to become different species. This research uses spiral gingers in the monocot genus Costus in Costa Rica and Panama to test these hypotheses about tropical speciation. Spiral gingers occupy a wide range of habitats, extending from lowlands to montane forests and from dense understory to forest edges, with different temperature, water, and soil conditions. They interact with many different orchid bee and hummingbird pollinators, highly specialized beetles that feed on young leaves, and ants that provide protection from herbivores in exchange for nectar. This work integrates phylogenetic studies, broad scale observational approaches, focused field experiments (reciprocal transplants and direct manipulations of interacting organisms and abiotic factors), and genetic mapping. It will determine how plants interact with and adapt to pollinators, herbivores, ant protectors, and climatic conditions across their geographic ranges. It will evaluate whether speciation is caused by traits and genes that have positive effects in one environment and negative effects in other environments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.