Historical and contemporary processes drive global phylogenetic structure across geographical scales: Insights from bat communities.

Aim: Patterns of evolutionary relatedness among co‐occurring species are driven by scale‐dependent contemporary and historical processes. Yet, we still lack a detailed understanding of how these drivers impact the phylogenetic structure of biological communities. Here, we focused on bats (one of the most species‐rich and vagile groups of mammals) and tested the predictions of three general biogeographical hypotheses that are particularly relevant to understanding how palaeoclimatic stability, local diversification rates and geographical scales shaped their present‐day phylogenetic community structure. Location: World‐wide, across restrictive geographical extents: global, east–west hemispheres, biogeographical realms, tectonic plates, biomes and ecoregions. Time period: Last Glacial Maximum (~22,000 years ago) to the present. Major taxa studied: Bats (Chiroptera). Methods: We estimated bat phylogenetic community structure across restrictive geographical extents and modelled it as a function of palaeoclimatic stability and in situ net diversification rates. Results: Limiting geographical extents from larger to smaller scales greatly changed the phylogenetic structure of bat communities. The magnitude of these effects is less noticeable in the western hemisphere, where frequent among‐realm biota interchange could have been maintained through the adaptive traits of bats. Bat communities with high phylogenetic relatedness are generally more common in regions that have changed less in climate since the Last Glacial Maximum, supporting the expectation that stable climates allow for increased phylogenetic clustering. Finally, increased in situ net diversification rates are associated with greater phylogenetic clustering in bat communities. Main conclusions: We show that the world‐wide phylogenetic structure of bat assemblages varies as a function of geographical extents, dispersal barriers, palaeoclimatic stability and in situ diversification. The integrative framework used in our study, which can be applied to other taxonomic groups, has not only proved useful to explain the evolutionary dynamics of community assembly, but could also help to tackle questions related to scale dependence in community ecology and biogeography. [ABSTRACT FROM AUTHOR]