Mesoamerica is a cradle and the Atlantic Forest is a museum of Neotropical butterfly diversity: Insights from the evolution and biogeography of Brassolini (Lepidoptera: Nymphalidae)

Abstract

Regional species diversity is ultimately explained by speciation, extinction, and dispersal. Here we estimate dispersal and speciation rates of Neotropical butterflies to propose an explanation for their distribution and diversity of extant species. We focus on the tribe Brassolini (owl butterflies and allies): a Neotropical group that comprises 17 genera and 108 species, most of them endemic to rainforest biomes. We infer a robust species tree using the multispecies coalescent framework and a dataset including molecular and morphological characters. This formed the basis for three changes in Brassolini classification: 1) Naropina, SYN. NOV. is subsumed within Brassolina; 2) Aponarope, SYN. NOV. is subsumed within Narope; 3) Selenophanes orgetorix, COMB. NOV. is reassigned from Catoblepia to Selenophanes. By applying biogeographical stochastic mapping, we found contrasting species diversification and dispersal dynamics across rainforest biomes, which might be partly explained by the geological and environmental history of each bioregion. Our results reveal a mosaic of biome-specific evolutionary histories within the Neotropics, where butterfly species have diversified rapidly (cradles: Mesoamerica), have accumulated gradually (museums: Atlantic Forest), or have alternately diversified and accumulated (Amazonia). Our study contributes evidence from a major butterfly lineage that the Neotropics are a museum and cradle of species diversity.