Diversification Times and Biogeographic Patterns in Apiales

This study provides an overview of the historical biogeography of the major clades of Apiales based on extensive taxon sampling from all major lineages of the order, and character sampling of sequence data from the plastid rpl16 intron and trnD-trnY-trnE-trnT intergenic spacers. Divergence times were estimated in BEAST using relaxed molecular clocks and six calibration points from three families. Biogeographic reconstructions were estimated in DIVA and Lagrange using stratified and non-stratified models, addressing alternative scenarios for taxa with conflicting or poorly supported placements. Our analyses in BEAST estimated the origin of Apiales to Australasia in the Early Cretaceous (c.117 Ma). Most major clades also appear to have originated in Australasia, with the youngest family (Apiaceae) originating in the Late Cretaceous, c. 87 Ma. Diversification of the early lineages appears to be influenced by vicariance events related to the break up of Africa and Australasia (Torricelliaceae from Griseliniaceae and Apiineae), Australasia from Zealandia (e.g., Myodocarpaceae and Araliaceae), and Antarctica from South America, Australia, and possibly Africa (main lineages of Apiaceae). Long-distance dispersal appears as the likely explanation for many younger lineages within major clades, including Subantarctic pathways (e.g., Griseliniaceae and Azorelloideae), across the Pacific and Indian Ocean Basins (e.g., Pittosporaceae and Araliaceae), from Asia across Europe into the Americas (Araliaceae).