Data from: Going to extremes: contrasting rates of diversification in a recent radiation of New World passerine birds

Recent analyses suggest that a few major shifts in diversification rate
may be enough to explain most of the disparity in diversity among
vertebrate lineages. At least one significant increase in diversification
rate appears to have occurred within the birds; however, several nested
lineages within birds have been identified as hyperdiverse by different
studies. A clade containing the finches and relatives (within the avian
order Passeriformes), including a large radiation endemic to the New World
that comprises ~8% of all bird species, may be the true driver of this
rate increase. Understanding the patterns and processes of diversification
of this diverse lineage may go a long way toward explaining the apparently
rapid diversification rates of both passerines and of birds as a whole. We
present the first multi-locus phylogenetic analyses of this endemic New
World radiation of finch relatives that includes sampling of all
recognized genera, a relaxed molecular clock analysis of its divergence
history, and an analysis of its broad-scale diversification patterns.
These analyses recover five major lineages traditionally recognized as
avian families, but identify an additional ten relatively ancient lineages
worthy of recognition at the family level. Time-calibrated diversification
analyses suggest that at least six of the fifteen family-level lineages
are significantly species-poor given the entire group’s background
diversification rate, whereas one—the tanagers of family Thraupidae—is
significantly more diverse. These differences are consistent with the low
speciation and extinction rates of island and ecologically-specialized
lineages previously documented across passerines as a whole. Finally, lack
of an age-diversity relationship within this clade suggests that, due to
rapid initial speciation, it may have experienced density-dependent
ecological limits on its overall diversity.