title: Molecular phylogenetic analysis of Commiphora (Burseraceae) yields insight on the evolution and historical biogeography of an "impossible" genus.
abstract: Expansion of the arid zone of sub-Saharan tropical Africa during the Miocene is posited as a significant contributing factor in the evolution of contemporary African flora. Nevertheless, few molecular phylogenetic studies have tested this hypothesis using reconstructed historical biogeographies of plants within this zone. Here, we present a molecular phylogeny of Commiphora, a predominantly tropical African, arid-adapted tree genus, in order to test the monophyly of its taxonomic sections and identify clades that will help direct future study of this species-rich and geographically widespread taxon. We then use multiple fossil calibrations of Commiphora phylogeny to determine the timing of well-supported diversification events within the genus and interpret these age estimates to determine the relative contribution of vicariance and dispersal in the expansion of Commiphora's geographic range. We find that Commiphora is sister to Vietnamese Bursera tonkinensis and that its crown group radiation corresponds with the onset of the Miocene.
authors.affiliation: George Mason University, Department of Environmental Science and Policy MSN 5F2, Fairfax, VA 22030, USA. aweeks3@gmu.edu
authors.forename: Andrea
authors.initials: A
authors.lastname: Weeks
authors.forename: Beryl B
authors.initials: BB
authors.lastname: Simpson
mesh_terms: D000349:Africa; D029403:Burseraceae / Q000145:classification / Q000235:genetics*; D002467:Cell Nucleus / Q000235:genetics; D018742:DNA, Chloroplast / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D049810:Genetic Speciation; D005843:Geography; D007194:India; D008270:Madagascar; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013020:South America; D013997:Time Factors
chemical_list: D018742:DNA, Chloroplast