Biodiversity is unevenly distributed on Earth and hotspots of biodiversity are often associated with areas that have undergone orogenic activity during recent geological history (i.e. tens of millions of years). Understanding the underlying processes that have driven the accumulation of species in some areas and not in others may help guide prioritization in conservation and may facilitate forecasts on ecosystem services under future climate conditions. Consequently, the study of the origin and evolution of biodiversity in mountain systems has motivated growing scientific interest. Despite an increasing number of studies, the origin and evolution of diversity hotspots associated with the Qinghai-Tibetan Plateau (QTP) remains poorly understood. We review literature related to the diversification of organisms linked to the uplift of the QTP. To promote hypothesis-based research, we provide a geological and palaeoclimatic scenario for the region of the QTP and argue that further studies would benefit from providing a complete set of complementary analyses (molecular dating, biogeographic, and diversification rates analyses) to test for a link between organismic diversification and past geological and climatic changes in this region. In general, we found that the contribution of biological interchange between the QTP and other hotspots of biodiversity has not been sufficiently studied to date. Finally, we suggest that the biological consequences of the uplift of the QTP would be best understood using a meta-analysis approach, encompassing studies on a variety of organisms (plants and animals) from diverse habitats (forests, meadows, rivers), and thermal belts (montane, subalpine, alpine, nival). Since the species diversity in the QTP region is better documented for some organismic groups than for others, we suggest that baseline taxonomic work should be promoted.

Functional traits offer a rich quantitative framework for developing and testing theories in evolutionary biology, ecology and ecosystem science. However, the potential of functional traits to drive theoretical advances and refine models of global change can only be fully realised when species-level information is complete. Here we present the AVONET dataset containing comprehensive functional trait data for all birds, including six ecological variables, 11 continuous morphological traits, and information on range size and location. Raw morphological measurements are presented from 90,020 individuals of 11,009 extant bird species sampled from 181 countries. These data are also summarised as species averages in three taxonomic formats, allowing integration with a global phylogeny, geographical range maps, IUCN Red List data and the eBird citizen science database. The AVONET dataset provides the most detailed picture of continuous trait variation for any major radiation of organisms, offering a global template for testing hypotheses and exploring the evolutionary origins, structure and functioning of biodiversity.

Tropical mountains are hotspots of biodiversity, but the factors that generate this high diversity remain poorly understood. To identify possible mechanisms that influence avian species assemblages in the tropical Andes, we studied the functional and phylogenetic diversity and the structure of species assemblages of an avian feeding guild. We analysed how functional and phylogenetic diversity, structure and composition of frugivorous bird assemblages changed along a 3300 m elevational transect from the lowlands to the tree line with a novel combination of functional and phylogenetic approaches, and used null models to infer possible drivers of the observed patterns. Species richness, functional richness and phylogenetic diversity decreased almost monotonically with increasing elevation, but assemblage structure and composition changed abruptly in the Andean foothills at around 1200 m. In the lowland assemblages, species were functionally and phylogenetically less similar than expected from null models, whereas species in the highland assemblages were functionally and phylogenetically more similar than expected by chance, suggesting an abrupt reduction in the number of functionally and phylogenetically distinct species in the transition from lowlands to the highlands. Nevertheless, the functional and phylogenetic evenness of the assemblages, i.e. the regularity of the spacing of species in functional trait space and phylogeny, remained constant along the gradient, which suggests that the mechanisms that influence the co‐occurrence of species within the assemblages are similar in lowlands and highlands. The observed differences between lowland and highland assemblages imply sharp distributional limits for frugivorous bird species in the Andean foothills, probably caused by environmental factors other than climate, e.g. changes in habitat types or topography, or independent species radiations in lowlands and highlands. These strong distributional limits may hinder uphill range shifts of frugivorous bird species, and the plant species they disperse, in the tropical Andes as a response to climate change.