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

在过去的十年里，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岛上进化的驱动力。该项目将使用没药属的两个特有谱系(50种，草本植物，草麻科)作为模型，以检验关于地理对马达加斯加西部季节性干燥的热带森林物种多样性的影响的假说。这些假说预测，物种的出现是由于1)分水岭的扩张和收缩、2)河流屏障和3)历史气候变化造成的孤立的结果。将使用一种结合微流控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提取959个核基因的子集。所得数据将用于重建这些物种的进化史，并将与基于标本的地图相结合，以检验主要的生物地理假说。作为这项研究的一部分开发的基因组标记还将评估它们在被子植物生命树上对其他物种的可转移性，这可能会为所有植物系统学家扩展方法学工具包。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，包括在全国会议上展示他们的研究成果。将提供更多的外联活动，通过持续的辅导活动，让K-12和本科生参与进来。

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.