Out-of-Africa: Origin of the Disjunct Distribution of Paleotropical Eneopterinae Crickets (Gryllidae, Xenogryllini)

Many groups of terrestrial plants and animals display a disjunct distribution pattern in the Paleotropics, being found almost exclusively in tropical Africa and Asia. The origin of such a pattern may be manifold, particularly for older lineages where plate tectonics potentially played an important role. Several potential colonisation routes may have been involved in dispersal events between the Afrotropics and tropical Asia, not to mention long-distance dispersal events through island hopping. To advance in the understanding of disjunct Paleotropical distributions, we focus on a tribe of Paleotropical crickets, the Xenogryllini. They supposedly originated in the Early Eocene, thus experiencing multiple past geological and environmental changes during their diversification. Resolving the evolutionary history of Xenogryllini is thus expected to shed light on the biogeographic processes that generated disjunct Paleotropical distributions. To tackle this, we assembled a multi-marker molecular dataset for the tribe encompassing all species. We carried out phylogenetic, molecular dating, and historical biogeography analyses. Our results provide a highly supported phylogenetic hypothesis for the tribe and suggest an out-of-Africa origin with several independent dispersal events towards Asia, likely involving distinct colonisation routes in the Neogene.