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.
