Multiple origins of parthenogenesis, and a revised species phylogeny for the Southeast Asian butterfly lizards, Leiolepis

Abstract

Hybridization often occurs in areas of secondary contact between closely related species. In some cases these hybridization events can create hybrid offspring that are reproductively viable as new parthenogenetic species. The genus Leiolepis contains nine species that collectively range throughout continental Southeast Asia. Of these, four are unisexual (some diploid and some triploid). We analyzed a multi-locus dataset within a multi-lineage coalescent framework to infer the origins of these parthenogenetic hybrid species. Our results provide evidence that repeated hybridization events between L.reevesii and L.guttata have led to the formation of all four distinct parthenogenetic species. Our data further suggest there have been low levels of mitochondrial introgression between L.belliana and L.reevesii at their contact zone in southern Cambodia. This work addresses contentious species boundaries and provides the first taxon-complete hypothesis of relationships for the butterfly lizards.