Corridors and Reservoirs: An Analysis of Inter‐Andean Historical Biogeography

ABSTRACT Aim The Andes are a global biodiversity hotspot, and the formation of this mountain range is linked to the rapid diversification of many lineages across the Tree of Life. The high species richness of the Andes might also act as a reservoir for lineages to disperse across the South American continent. Recent syntheses of Andean geological history and the accumulation of phylogenetic studies of different Andean clades present an opportunity for a synthesis of the historical biogeography of the Andean biota. Location The Andes. Taxon All taxonomic groups. Methods We conducted a meta‐analysis of phylogenetic studies, scoring disjunction events within and out of the Andes inferred from biogeographic reconstructions. Results We show that, across time and clades, dispersals among regions in the Andes are approximately as common as dispersals out of the Andes. The greatest number of extra‐Andean disjunctions originated from the northern Andes, even though the northern section of this mountain range is the most recently uplifted. There has been continued bi‐directional movement within the Andes over the last 50 million years. Dispersals northward occur at a slightly, but significantly, greater rate than dispersals southward. Andean plant crown clades tended to be older than animal crown clades, which almost exclusively originate in the last 30 million years. Main Conclusions Our findings reveal that the Andes have equally acted as a reservoir and a corridor of biodiversity across clades with widely divergent dispersal strategies.