Colonization and diversification: towards a phylogeographic synthesis for the Canary Islands

Recently, the Canary Islands have become a focus for studies of the coloniz ation and the diversification of different organisms. Some authors have con sidered Canarian endemisms as relicts of Tertiary origin, but new molecular data suggest a general pattern of continental dispersion followed by in si tu speciation. Recent phylogeographic studies are revealing variants of the simple stepping-stone colonization model that seems to hold for many Hawai ian groups. Many factors can generate deviations from such a pattern: the s tochastic nature of colonization, competitive exclusion, phylogenetic const raints on adaptive evolution and extinction, An understanding of island col onization and diversification can best be developed from an ecosystem level synthesis as more data for the Canarian archipelago come to hand.