What causes certain groups of organisms to have more species than others? This study seeks an answer by examining the relationship between ecological niche evolution and diversification in the largest family of songbirds, the tanagers (Thraupidea). Researchers compiled distributions using GBIF-mediated data and other sources, then constructed niche models using 19 bioclimatic variables. Phylogenetic analysis divided the family into clades, scoring them according to climatic niche evolution. These scores correlate strongly with species richness, which correlate further with niche volume clade age and geographical area. The authors suggest that the study provides a replicable method for analysing niche evolution in large, widespread clades.
Title PO and Burns KJ (2015) Rates of climatic niche evolution are correlated with species richness in a large and ecologically diverse radiation of songbirds. Ecology Letters. Wiley-Blackwell, 433–440. Available at doi:10.1111/ele.12422.