Diversification in old, climatically buffered, infertile landscapes: tracing the evolutionary history of a frog clade (Bokermannohyla: Hylidae) that is endemic to campo rupestre

Abstract

Abstract The ‘accentuated persistence’ hypothesis suggests long lineage persistence in OCBILs (old, climatically buffered, infertile landscapes), such as campo rupestre (rupestrian grasslands). We tested this hypothesis using a group of frogs endemic to this ecosystem as a model. We built a multilocus molecular phylogeny to define our study group—a clade in which all species inhabit campo rupestre. We then delimited lineages and constructed a time-calibrated species tree. To investigate the origin of this clade, and the events and processes that contributed to its diversification and current distribution, we inferred its biogeographic history. The Bokermannohyla pseudopseudis clade, comprising four species from Chapada Diamantina and two from the Brazilian central plateau, originated during the Early Miocene (∼18.75 Mya). Its diversification occurred mainly between the Pliocene and Pleistocene. The ancestral range of this clade includes the Espinhaço Range and Chapada Diamantina. We found that vicariance probably isolated the clade in Chapada Diamantina, while a founder event probably enabled the colonization of the Brazilian central plateau. These findings suggest that the B. pseudopseudis clade is not an ancient lineage, contradicting the ‘accentuated persistence’ hypothesis. The clade’s current geographic distribution was probably influenced by tectonic activity and climatic changes that occurred since the Early Miocene.