How tectonic, volcanic and climatic processes in Andean ‘sky islands’ shaped the diversification of endemic ground beetles

Aim The Andean superpáramo ecosystem, above c. 4200 m a.s.l., currently forms an archipelago of isolated ‘sky islands’ which provides a unique setting to study biogeography. However, there is still poor understanding how past geological events, together with climatic changes, have shaped the distribution life in this ecosystem. Our aim was investigate importance biogeographical barriers local diversifications and analyse populations become on current islands’. Location Neotropics, Andes, Páramo, Ecuador. Taxon Coleoptera, Carabidae, Platynini, Dyscolus. Methods We first used distributional data 45 specialist species define areas endemism northern then selected 34 12 perform high-throughput genome skimming approach encompassing complete mitogenome nuclear ribosomal cluster. also generated time-calibrated estimation for diversification group, compared it geochronological data. Results A high proportion (60%) sampled are microendemic, being restricted single mountain summit. Three mutually exclusive limited by deep transverse valleys across Pliocene speciation events related these orogenic barriers. phylogeny obtained from genome-skimming robust base endemic throughout Plio-Pleistocene. Main conclusions opening Interandean Valley did not play significant role group prior Pleistocene. More recently, multiple various volcanoes independently colonizing habitat during repeated cycles glacial–interglacial periods. results highlight joint contribution orogeny fluctuations explaining patterns distribution. Each had different colonization history, its reaching at cycles. can provide powerful tool constrain processes responsible topographic changes along Cordillera.