DISSERTATION RESEARCH: Tracking Timing of Migration and Diversification Across North and South America in Agalinis (Orobanchaceae)

来自不同生物群系的生物的潜在进化历史或系统发育为理解这些谱系在地理上的起源，它们随后如何多样化以及这些生物群系在过去如何组装提供了一个框架。该项目探讨了龙葵属（Orobanchaceae）的进化关系，龙葵属是一个开花植物属，约有70种，分布在新词，并与南美洲两个公认的生物多样性热点中心：安第斯山脉和巴西塞拉多地区的多样性中心。Agalinis是研究两大洲之间、安第斯山脉和塞拉多山脉之间的历史生物地理学和多样性，以及快速辐射到南美洲之后的形态进化模式的理想分支。除了使用标准的系统发育和分化时间估计方法外，本研究还将采用一种新开发的多物种聚合方法来估计南美龙鸡进化枝的物种树和分化时间。我们的目标是：1)收集第一个广泛采样的Agalinis系统发育，2)使用标准系统发育方法和新的南美进化枝聚聚方法估计物种树和分化时间，3)调查南北美洲之间以及南美洲安第斯山脉和塞拉多山脉之间的迁徙和多样化，努力将多样化的潜在变化与地质和古气候重建联系起来。4)研究形态特征演化。本研究的应用范围超出了琼脂伞属植物的系统学研究，不仅对研究南美洲谱系的多样性和特征进化，而且对新热带地区的比较系统发育研究具有重要意义。该项目广泛依赖于已建立的国际合作，特别是在巴西。研究结果将通过同行评议的出版物、国家会议上的报告以及my-plant.org门户网站进行传播。田间植物的照片已经存放在寄生植物收集网站上，该网站向研究人员和公众提供信息。联合项目负责人正在指导一名本科生进行一个与本文所述研究重叠的小项目，并将在2013年指导一名巴西本科生参加USP的实验室交换。此外，联合项目负责人将继续参与美国国家科学基金会支持的《种植科学》在线高中指导计划，进一步推动拟议研究的教育影响。

The underlying evolutionary history, or phylogeny, of organisms from diverse biomes provide a framework for understanding where these lineages originated geographically, how they have subsequently diversified, and how these biomes were assembled in the past. This project explores evolutionary relationships in Agalinis (Orobanchaceae), a flowering plant genus of approximately 70 species with a New Word distribution and with South American centers of diversity in two recognized biodiversity hotspots: the Andes and the Cerrado of Brazil. Agalinis is an ideal clade for investigating historical biogeography and diversification between the two continents and between the Andes and Cerrado, as well as patterns of morphological evolution following a rapid radiation into South America. In addition to using standard phylogenetic and divergence time estimation approaches, this research will also employ a newly developed multi-species coalescent approach for estimation of the species tree and divergence times within the South American clade of Agalinis. Our goals are to: 1) assemble the first broadly-sampled phylogeny of Agalinis, 2) estimate the species tree and divergence times, using both standard phylogenetic and new coalescent methods for the South American clade, 3) investigate migration and diversification between North and South America and between the Andes and the Cerrado within South America, with efforts to correlate potential shifts in diversification with geological and paleoclimatic reconstructions, and 4) investigate morphological character evolution. The utility of this research extends beyond the systematics of Agalinis and will be a valuable contribution not only to studies of diversification and character evolution of lineages in South America, but also to comparative phylogenetic research in the Neotropics. This project relies extensively on established international collaborations, particularly in Brazil. The results of the research will be disseminated through peer-reviewed publications, presentations at national conferences, and through the my-plant.org web portal. Photos of plants in the field have already been deposited with the Parasitic Plant Collection, a website which provides information to researchers and the public. The co-PI is supervising an undergraduate student on a small project overlapping with the research outlined here, and will mentor a Brazilian undergraduate in a lab exchange from USP in 2013. Additionally, the co-PI will continue her involvement with the NSF-supported Planting Science online high school mentoring program, furthering the educational impact of the proposed research.