Historical biogeography and comparative phylogeography of the Mexican genus Bakerantha (Bromeliaceae): insights into evolution and diversification

Abstract

We studied the rupicolous and dioecious species of Bakerantha (Bromeliaceae) that grow as narrow endemics in central-eastern Mexico. We aimed to describe the spatio-temporal framework in which Bakerantha and its species originated using a phylogeographic and population genetics approach. We carried out population genetics analyses on 29 populations of the five Bakerantha spp., using plastid and nuclear DNA sequences. The data were used to analyse their diversity, genetic structure and demography, to carry out molecular dating and to reconstruction their ancestral area. Our analyses revealed that speciation in Bakerantha began in the Late Pliocene, associated with vicariance resulting from the rise of the Trans-Mexican Volcanic Belt, a barrier that isolated the Bakerantha spp. to its north and south, and subsequent dispersal events in the Sierra Madre Oriental. Genetic data suggest that the species have achieved a high degree of genetic differentiation and variation, but most of them lack intraspecific structure, even though species have remained stable over the time due their life history traits.