Soto-Trejo, FabiolaMatzke, NicholasSchilling, Edward E.Massana, Kathryn A.Oyama, KenLira, RafaelDavila, Patricia2019-08-090024-4074http://hdl.handle.net/1885/164944Mexican dry environments are widespread and characterized by a rich flora and fauna in terms of both overall species diversity and endemism, but the factors that have shaped this diversity remain unclear. In this study, we evaluated hypotheses concerning the biogeographical origin and evolutionary history of Florestina (Asteraceae) in Mexican dry environments. For this, we generated a time-calibrated phylogenetic tree from the nuclear non-coding external and and internal transcribed spacers (ETS, ITS), using the program BEAST. Based on this phylogenetic tree, we employed the package BioGeoBEARS to infer the historical biogeography of the genus, comparing different biogeographical models and estimating the ancestral range probabilities. Our time-calibrated phylogenetic tree suggested that the genus Florestina diverged during the early Pliocene c. 5.2 Mya and diversification continued throughout the Pleistocene. Furthermore, results suggest that the biogeographical origin of the Hymenothrix/Palafoxia/Florestina clade was in Nearctic regions, not in Neotropical regions as previously suggested. We hypothesize that the ancestor of Florestina became disjunct and isolated in tropical dry forests of southern Mexico from Palafoxia after the rifting of the Baja California peninsula from the Mexican mainland.F.S.-T. wishes to thank the Posgrado en Ciencias Biológicas and the Programa de Becas Posdoctorales both at UNAM for continuous support throughout this research. This work was also supported by Consejo Nacional de Ciencia y Tecnología (CONACYT) through a Doctoral Dissertation grant (171389). N.J.M. was supported by the National Institute for Mathematical and Biological Synthesis, an Institute sponsored by the National Science Foundation, the U.S. Department of Homeland Security and the U.S. Department of Agriculture through NSF Award #EFJ0832858, with additional support from The University of Tennessee, Knoxville. N.J.M. was also funded by the Australian Research Council’s Discovery Early Career Researcher Award #DE150101773, and by The Australian National University. F.S.T. was supported by two Short-Term Visitor grants from NIMBioS in 2014 and 2015. K.A.M. was supported by the National Institutes of Health Program for Excellence and Equity in Research Grant [R25 5R25GM086761-06] and the Ecology and Evolutionary Biology Department at the University of Tennessee, Knoxville.application/pdfen-AU© 2017 The Linnean Society of London201710.1093/botlinnean/box0692019-03-31