The Role of Geographically Structured Coevolution in Long Term Diversification: A Test Using Joshua Tree and its Pollinator Moths

共同进化是物种相互作用的重要驱动力。 我们已经知道，它可以在生态时间内推动或多或少孤立的种群在形态和生态上的多样化。下一个重要的问题是，这种变异是否会持续下去，从而有助于产生物种多样性，或者它是否会在不断变化的生态环境中消失。这个项目是对这个问题的第一次检验。它利用了著名的约书亚树和它的独家授粉者，两种丝兰蛾之间的专性，有益的关系。这些蛾要么单独出现，要么共存于约书亚树范围的不同部分。这是一个很好的模型，因为这种关联已经持续了很长时间，植物和蛾的性状在物种之间和物种内部都有差异。此外，约书亚的地理范围是高度分散的，在过去的气候条件下，有一个众所周知的可变连接历史。具体而言，该项目将使用分子和形态学数据来测试对历史基因流，当前隔离和形态变异的预测。它们一起可以为共同进化在推动物种形成中的作用问题提供强有力的答案。 研究结果将立即在保护生物学中发挥更广泛的作用，因为答案将影响遗传信息保护战略，以及气候变化生物学，其中丝兰是敏感的指示物种。作为一个具有巨大公共利益的物种和莫哈韦沙漠的象征，以及维护沙漠社区的关键物种，研究结果将立即应用于公共机构。在更广泛的教育背景下，丝兰和丝兰蛾在教科书和科学中心和公园等公共教育环境中占有突出地位。该项目将在这些地区进一步推广，并在公园和纪念碑中提供公众和护林员教育。

Coevolution is an important driver in species interactions. We already know that it can drive diversification in morphology and ecology among more-or-less isolated populations in ecological time. An important next question is whether this variation persists in such a way as to contribute to generating species diversity, or if it is lost amidst changing ecological context. This project provides a first test of this question. It uses the obligate, beneficial relationship between the well-known Joshua Tree and its exclusive pollinators, two yucca moth species. These moths occur either alone or coexist in different parts of the joshua tree range. It is an excellent model because the association has persisted for a very long time, and plant and moth traits have diversified between and within the species. Furthermore, the geographic range of joshua tree is highly fragmented and has a well-understood history of variable connectivity during past climate regimens. Specifically, the project will use molecular and morphological data to test predictions about historical gene flow, current isolation, and morphological variation. Together they can provide strong answers to the question about the role of coevolution in driving speciation. The results will be of immediate broader utility in conservation biology, as the answers would affect genetically informed conservation strategies, and in climate change biology, where yuccas are sensitive indicator species. Being a species of great public interest and a symbol of the Mojave desert, and a key species for maintenance of desert communities, the results will have immediate application for public agencies. In a broader educational context, yuccas and yucca moths figure prominently in textbooks, and in public education settings such as science centers and parks. The project will further outreach in these areas, and provide public and ranger education in parks and monuments.