Single origin of the Mascarene stick insects: ancient radiation on sunken islands?

摘要: The study of islands as model systems plays a key role in understanding many evolutionary processes. Knowledge the historical events leading to present-day island communities is pivotal for exploring fundamental mechanisms speciation and adaptation. remote Mascarene archipelago (Mauritius, Reunion, Rodrigues), considered be product an age-progressive trend north-to-south volcanic activity Indian Ocean, hosts remarkably diverse, endemic threatened concentration flora fauna that has traditionally been biogeographically related Madagascar Africa. To explore diversity stick insects (Phasmatodea), we constructed global phylogeny from approximately 2.4 kb mitochondrial nuclear sequence data more than 120 species representing all major phasmatodean lineages. Based on obtained time-calibrated molecular tree demonstrate current phasmid community archipelago, which consists members four presumably unrelated traditional subfamilies, result single ancient dispersal event Australasia started radiating between 16–29 million years ago, significantly predating age Mauritius (8–10 years). We propose diversified landmasses now eroded away, north Mauritius. In consequence, have probably persisted Ocean until emergence not only served stepping stones colonisation during sea-level lowstands, but long-lasting cradles evolution. These most likely allowed adaptive significant sources contributed biomes megadiverse Madagascar.