DISSERTATION RESEARCH: Uncovering the geographic pattern of species evolution in Madagascar using the myrrh genus (Commiphora Jacq.) and a target-enriched nuclear genomic approach

在过去的十年中，对马达加斯加非凡的生物多样性及其起源的科学探索已经转向描述该岛内部进化的驱动因素。该项目将使用没药树属（50种，没药科，麻丝科）的两个特有谱系作为模型，以测试有关地理对马达加斯加西部季节性干燥热带森林物种多样化影响的假设。这些假设预测物种的出现是由于1)流域扩张和收缩、2)河流屏障和3)历史气候变化造成的隔离的结果。将使用结合微流体扩增和大规模并行测序的经济高效的高通量方法，从所有特有物种中取样959个核基因子集。结果数据将用于重建这些物种的进化史，并将与基于标本的制图相结合，以测试总体生物地理学假设。作为本研究的一部分开发的基因组标记也将被评估其在被子植物生命树上的其他物种的可转移性，这可能会扩展所有植物系统学家的方法工具包。这项研究将为两名本科生提供指导机会，并将支持他们的专业发展，包括在国家会议上介绍他们的研究。通过持续的指导活动，将为K-12和本科生提供额外的外展服务。

In the last decade, scientific exploration of Madagascar's remarkable biodiversity and its origin has shifted to characterizing the drivers of evolution within the island. This project will use two endemic lineages of the myrrh tree genus (50 spp., Commiphora, Burseraceae) as models to test hypotheses regarding the influence of geography on species diversification in the seasonally dry tropical forests of western Madagascar. These hypotheses predict that species have arisen as a consequence of isolation caused by 1) watershed expansion and contraction, 2) river barriers, and 3) historical climate change. A subset of 959 nuclear genes will be sampled from all endemic species using a cost-effective high-throughput method that combines microfluidic amplification and massively-parallel sequencing. The resulting data will be used to reconstruct the evolutionary history of these species and will be combined with specimen-based mapping to test the overarching biogeographical hypotheses. Genomic markers developed as part of this research will also be evaluated for their transferability to other species across the angiosperm tree of life, which may expand the methodological toolkit for all plant systematists. This research will provide mentorship opportunities for two undergraduate students and will support their professional development, including presentation of their research at a national meeting. Additional outreach will be provided to involve K-12 and undergraduate students through ongoing mentorship activities.