Recent biogeographic and ecoinformatic studies of palms provide a global context for the spatio-temporal evolution of palms and the tropical rain forests that they inhabit. Palms display high rain forest niche conservatism, with >90% of species occurring in this biome. The global distribution of clades and species richness is highly structured, suggestive of complex, differentiated patterns of evolutionary drivers. Macroecological studies show that palm species richness is globally contingent on climatic variables typical of the humid tropics, while island palm floras are also influenced by area and habitat heterogeneity variables. Incorporation of phylogenetic evidence reveals strong imprints of in situ diversification in the Neotropics and on islands, of biotic interchange, and of forest loss in Africa. We inferred an origin for palms in the mid-Cretaceous of Laurasia, which is significant for our understanding of rain forests because fossil evidence for this biome prior to the Palaeocene is weak. Lineage diversification in palms has proceeded in a constant manner from 100 Ma at least until the Miocene, conforming to the museum model of diversification. Since the Miocene, diversification rates of species-rich lineages have increased, consistent with ecoinformatic evidence for the role of in situ radiations on islands and the Neotropics identified above. Species-level phylogenetic studies and ecoinformatic analyses of the impact of past climate change, geological processes and sea level change on palm diversity are now required to add essential detail to the broad global picture given here.
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International Conference on Comarative Biology of Monocotyledons, 2013