Evidence of a South American origin for the Drosophila repleta group (Diptera: Drosophilidae)

Abstract

The Drosophila repleta group is one of the most widely used model systems for studying adaptation and speciation. Traditionally, five subgroups are recognized within the repleta group: fasciola, hydei, mercatorum, repleta and mulleri. A sixth subgroup, inca, was the last to be defined. The inca species subgroup includes three species: Drosophila inca, Drosophila huancavilcae and Drosophila yangana, all of which are endemic to Ecuador and Peru. Previous molecular phylogenetic studies have been inconclusive regarding the geographic location, time and mode of diversification of lineages within the repleta group. By applying a phylogenetic and biogeographical analysis of 54 taxa belonging to the repleta, nannoptera, atalaia and virilis groups, the aim of this study was to: (1) determine the relationships between the inca subgroup and the other five subgroups within the repleta group, (2) improve the unresolved branching and low supports of the early divergent lineages in the repleta group phylogeny and (3) estimate the geographic and temporal context of the early divergence within the repleta group. Based on these findings, it is proposed that the Drosophila repleta group first diversified during the mid-late Miocene, most likely following the uplift of the Northwestern Andes.

Keywords

• repleta lineage
• evolutionary relationships
• systematics
• phylogeny
• biogeography