TreeBASE Search-Trees for study 17068

@ARTICLE{TreeBASE2Ref24166, author = {Alejandra Vazquez-Lobo and Gisela Aguilar Morales and Salvador Arias and Jordan Golubov and Tania Hern?ndez-Hern?ndez and Mar?a Carmen Mandujano}, title = {Phylogeny and biogeography of Astrophytum}, year = {2015}, keywords = {Astrophytum; Cacteae; Biogeography; Chihuahuan Desert}, doi = {}, url = {}, pmid = {}, journal = {Systematic Botany}, volume = {}, number = {}, pages = {}, abstract = {Although efforts to infer a complete phylogeny for Cactaceae family have been performed, delimitation of genera has resulted problematic. Even for small groups, such as the genus Astrophytum, membership to the genus and relationships at the species level remain uncertain. Specifically, the taxonomic uncertainty within Astrophytum involves one species assigned to a different genus (Digitostigma) and a possible taxonomic synonym between A. myriostigma and A. coahuilense. Even though Astrophytum is considered endemic to the Chihuahuan Desert, two species are distributed in an unusual region for the Cacteae tribe. The purpose of this study is to obtain a phylogenetic hypothesis for the genus Astrophytum (Cactaceae), and to estimate a possible date for the origin of the clade and its ancestral geographic distribution, to better understand the history of the group and clarify its taxonomic classification. Sequences of three chloroplast loci (partial rbcL gene, trnL-trnF region, and trnK-matK region) were used to infer a phylogeny with Bayesian Inference and Maximum Likelihood methods. Divergence times for each node were estimated using an uncorrelated lognormal clock, implemented in BEAST. Inferences of ancestral distribution areas were conducted using methods implemented in RASP. Our results suggest that genus is monophyletic, with six species grouped in two clades. Genus Digitostigma appears to be an Astrophytum derived species. A. myriostigma and A. coahuilense samples were grouped in independent clades, therefore supporting them as distinct species. Our estimated dates show a possible origin of the group and its posterior diversification in the Late Miocene, during a transition to drier climates on North America. Occurrences of Astrophytum species out of the Chihuahuan Desert are attributable to two recent independent events.} }