Collaborative Research: Molecular Phylogenetics and Coevolution in Yuccas and Yucca Moths

科尔盖特大学的James H. Leebens-Mack博士与范德比尔特大学的N. Olof Pellmyr博士合作，获得了一项研究植物与飞蛾之间进化相互作用的资助。共同进化是推动多样化和物种形成的重要过程，但由于缺乏生物模型群的系统发育（家谱），对这一过程的理解受到阻碍。丝兰和丝兰蛾是一种义务授粉的互惠关系，通常被认为是共同进化的最明显的例子之一。他们建议使用多基因测序来完成丝兰（龙舌兰科）和丝兰蛾（原蛾科：鳞翅目）的生物系统发育。研究结果将用于检验共同进化、平行物种形成和宿主转移在多样化中的作用等假设。比较分析将用于量化飞蛾和植物个体性状水平上的共同进化。目的1是基于丝兰属植物的DNA序列数据建立一个稳定的系统发育。他们将使用多基因方法，利用核和细胞质标记，建立一个强大的物种水平的系统发育。在目标2中，pi将使用类似的方法来解决一群快速多样化的丝兰蛾群体之间的关系，这些群体的起源与许多生活史进化相吻合。目的3利用飞蛾和植物系统发育来检验与共同进化有关的假设。我们将估算共种的分布和频率，并通过比较分析来检验寄主迁移和产卵行为的进化如何影响食性宽度和多样化率。最后，飞蛾和植物之间潜在的利益冲突应该通过选择对飞蛾产卵成功和对植物种子破坏最小化有重要影响的性状来体现。飞蛾产卵器形状、产卵位置和花子房形状和厚度是种间高度变异的候选性状。它们将成为祖先重建和比较分析的重点，以划分多样性的共同进化和系统发育成分。总之，该项目的结果应该为任何共同进化和互惠模式提供物种水平上的第一个系统发育框架。它将为分析共同进化如何在性状水平上起作用以促进生物多样性的产生开辟一个场所。

DEB-0075871James H. Leebens-Mack Dr. James H. Leebens-Mack of Colgate University, in collaboration with Dr. N. Olof Pellmyr at Vanderbilt Univerisity has beeen awarded a grant to study coveolutionary interactions between plants and moths. Coevolution is an important process in driving diversification and speciation, but understanding of this process is hampered by a lack of phylogenies (family trees) for model groups of organisms. Yuccas and yucca moths are tied in an obligate pollination mutualism, commonly cited as one of the most obvious examples of coevolution. The PIs propose to use multi-gene sequencing to complete robust organismal phylogenies for both yuccas (Agavaceae) and yucca moths (Prodoxidae: Lepidoptera). The results will be used to test hypotheses of coevolution, parallel speciation, and the role of host shifts in diversification. Comparative analyses will be used to quantify coevolution at the level of individual traits in the moths and plants. The goal of objective 1 is to establish a stable phylogeny based on DNA sequence data for the plant genus Yucca. They will use a multi-gene approach, using both nuclear and cytoplasmic markers, to establish a robust species-level phylogeny. In objective 2, the PIs will use a similar approach to resolve relationships among a cluster of rapidly diversified groups of yucca moths whose origin coincided with much life history evolution. Objective 3 utilizes the moth and plant phylogenies to test hypotheses related to coevolution. The distribution and frequency of cospeciation will be estimated, and and comparative analysis emplyed to test how host shifting and evolution of oviposition behavior affect diet breadth and rates of diversification. Finally, the underlying conflict of interests between moth and plant should manifest through selection on traits with major effects on oviposition success in the moth and minimization of seed destruction in the plant. Moth ovipositor shape, oviposition site, and floral ovary shape and thickness are candidate traits that are highly variable among species. They will be the focus of ancestor reconstruction and comparative analyses to partition coevolutionary and phylogenetic components of diversification. Together, the results from the project should provide the first phylogenetic framework at the species level for any of the models of coevolution and mutualism. It will open a venue for analyzing how coevolution acts at the trait level to contribute to the generation of biodiversity.