Gostel, Morgan , Weeks, Andrea .
Reconstructing patterns of microendemism in Madagascan seasonally dry tropical forests: Dating the divergence of four radiations in the myrrh genus, Commiphora Jacq. (Burseraceae), using a five-marker phylogeny.
The myrrh genus, Commiphora Jacq., is the most species rich in the Burseraceae, yet its diversity is poorly understood. We have sampled approximately 61% of the species in Commiphora and over 90% of the species from Madagascar. A nearly comprehensive sampling of Madagascan Commiphora has contributed to a molecular phylogeny based on two nuclear (ETS and ITS) and three chloroplast spacers (ndhF—rpl32, psbA—trnH, and trnD—trnT). Previous studies have suggested that Commiphora has resulted from two dispersal events from continental Africa to Madagascar; however, we report a minimum of four such dispersal events. We have estimated the timing of these dispersal events and propose areas of endemism using species range and geographic information. Using this information, we perform ancestral area reconstruction to test three biogeographic hypotheses for each of the four radiations of Madagascan Commiphora. We identify shortcomings for understanding diversification in Madagascar and suggest mechanisms to overcome such challenges.
1 - George Mason University, Environmental Science And Policy, David King Hall, MSN 5F2, 4400 University Dr., Fairfax, VA, 22030-4444, USA
Presentation Type: Oral Paper:Papers for Sections
Candidate for Awards:None