The evolutionary history of bees in time and space

Bees are the most significant pollinators of flowering plants. This partnership began ca. 120 million years ago, but the uncertainty of how and when bees spread across the planet has greatly obscured investigations of this key mutualism. We present a novel analysis of bee biogeography using extensive new genomic and fossil data to demonstrate that bees originated in Western Gondwana (Africa and South America). Bees likely originated in the Early Cretaceous, shortly before the breakup of Western Gondwana, and the early evolution of any major bee lineage is associated with either the South American or African land masses. Subsequently, bees colonized northern continents via a complex history of vicariance and dispersal. The notable early absences from large landmasses, particularly in Australia and India, have important implications for understanding the assembly of local floras and diverse modes of pollination. How bees spread around the world from their hypothesized Southern Hemisphere origin parallels the histories of numerous flowering plant clades, providing an essential step to studying the evolution of angiosperm pollination syndromes in space and time. •Bees likely originated in Gondwana before the breakup of Africa and South America•The geological history of southern continents impacted early bee diversification•Northward range expansions in the Tertiary impacted modern bee distribution•Southern Hemisphere origin of bees parallels the histories of many plant groups Almeida, Bossert, et al. combine phylogenomics and the fossil record to propose a comprehensive hypothesis of bee biogeography. Bees originated in Gondwana and later colonized all continents through a series of events that parallel the histories of numerous flowering plants, offering opportunities to interpret the evolution of pollination in space.