The phylogeography of the cycad genus Dioon (Zamiaceae) clarifies its Cenozoic expansion and diversification in the Mexican transition zone

The current genetic structure and species diversity of Dioon depict the history of expansion and diversification of the northernmost Neotropical provinces. Past biogeographic connectivities were favoured by elevated topographies, since mountain systems served as corridors for the migration of Dioon and as refugia of tropical communities that diversified during the formation of modern Neotropical forests.