Species richness in a tropical biodiversity hotspot

That biological diversity is higher in tropicalregions is one of the longest standingpatterns in macroecology, yet a consensusexplanation of this diversity remains elusive(reviewed by Jablonski et al., 2006). Evolu-tionary processes that influence speciesrichness are, in simple terms, speciation,extinction and dispersal. There are numer-ous mechanistic hypotheses and empiricalinvestigations of the factors that may influ-ence the relative rates of speciation andextinction, and hence, biodiversity (e.g.Mittelbach et al., 2007).Climate has long been recognized as animportant abiotic factor that influencesspecies distribution patterns in both tem-perate and tropical regions (e.g. Wiens GMittelbach et al., 2007). As genetic datasetsfor multiple taxa from diverse regionsbecome available, the application of non-traditional uses of molecular data (e.g. PDand ED) may prove fruitful for assessingcommunity diversity structure and under-standing global patterns of species richness.Finally, compiling data for many taxa withvaried life history and dispersal capabilitiesis necessary to fully assess mechanisms anddrivers of diversification.Jeanne M. Robertson