Two ways to be endemic. Alps and Apennines are different functional refugia during climatic cycles

Endemics co-occur because they evolved in situ and persist regionally or becausethey evolved ex situ and later dispersed to shared habitats, generating evolutionaryor ecological endemicity centres, respectively. We investigate whether different en-demicity centres can intertwine in the region ranging from Alps to Sicily, by studyingtheir butterfly fauna. We gathered an extensive occurrence data set for butterflies ofthe study area (27,123 records, 269 species, in cells of 0.5 × 0.5 degrees of latitude-longitude). We applied molecular-based delimitation methods (GMYC model) to26,557 cytochrome c oxidase subunit 1 (COI) sequences of Western Palearctic but-terflies. We identified entities based on molecular delimitations and/or the checklistof European butterflies and objectively attributed occurrences to their most probableentity. We obtained a zoogeographic regionalisation based on the 69 endemics of thearea. Using phylogenetic ANOVA we tested if endemics from different centres differfrom each other and from nonendemics for key ecological traits and divergence time.Endemicity showed high incidence in the Alps and Southern Italy. The regionalisationseparated the Alps from the Italian Peninsula and Sicily. The endemics of differentcentres showed a high turnover and differed in phylogenetic distances, phenologyand distribution traits. Endemics are on average younger than nonendemics and thePeninsula-Sicily endemics also have lower variance in divergence than those from theAlps. The observed variation identifies Alpine endemics as paleoendemics, now oc-cupying an ecological centre, and the Peninsula-Sicily ones as neoendemics, that di-verged in the region since the Pleistocene. The results challenge the common view ofthe Alpine-Apennine area as a single “Italian refugium”