An examination of speciation, extinction, and evolutionary relationships in plants from two continents
Molecular phylogenetic studies using the chloroplast-encoded matK, rps16, psbA-trnH, and trnL-trnF genes are underway to examine relationships among species of the plant genus Aneilema (family Commelinaceae) and to clarify the relationship of Aneilema to other genera in tribe Commelineae, particularly Pollia, Polyspatha, and Rhopalephora.The genus Aneilema consists of 64 species in seven sections, distributed primarily in tropical Africa and Australia. The species sampled represent all seven sections plus Aneilema brasiliense, whose generic position was considered uncertain.Aneilema brasiliense is found to fall outside of the rest of Aneilema and is either sister to Polyspatha or to a Pollia/Polyspatha clade. The basal grade of Aneilema consists of species of two sections, the Australian sect. Aneilema and African sect. Amelina. Amelina appears to be polyphyletic. Strong support is found for the monophyly of sect. Brevibarbata based on two West African and one South Africa forest species. The East African section Lamprodithyros is also monophyletic. Rhopalephora is placed within Aneilema. The inclusion of Rhopalephora within Aneilema and the exclusion of A. brasiliense from the genus would render Aneilema monophyletic.Sufficient molecular data to construct a phylogentic tree for the genus Portea (family Bromeliaceae) were not obtained, so all analyses focused on Commelinaceae species.The Commelinaceae molecular phylogeny will be used to evaluate speciation and extinction rates in the family.
Faculty Mentor: Timothy Evans, Biology
Corey presented at the Annual Meeting of the Botanical Society of America July 25-29, 2009 in Southbird, UT.