title: The tempo of avian diversification during the Quaternary.
abstract: It is generally assumed that the Quaternary was a period of heightened diversification in temperate vertebrate organisms. Previous molecular systematics studies have challenged this assertion. We re-examined this issue in north temperate birds using log-lineage plots and distributions of sister-taxon distances. Log-lineage plots support earlier conclusions that avian diversification slowed during the Quaternary. To test plots of empirical sister-taxon distances we simulated three sets of phylogenies: constant speciation and extinction, a pulse of recent speciation, and a pulse of recent extinction. Previous opinions favour the model of recent speciation although our empirical dataset on 74 avian comparisons failed to reject a distribution derived from the constant and extinction models. Hence, it does not appear that the Quaternary was a period of exceptional rates of diversification, relative to the background rate.
authors.affiliation: J. F. Bell Museum of Natural History, University of Minnesota, St Paul, MN 55108, USA. rzink@biosci.cbs.umn.edu
authors.forename: Robert M
authors.initials: RM
authors.lastname: Zink
authors.forename: John
authors.initials: J
authors.lastname: Klicka
authors.forename: Brian R
authors.initials: BR
authors.lastname: Barber
mesh_terms: D000818:Animals; D001717:Birds / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation; D016013:Likelihood Functions; D008957:Models, Genetic; D010802:Phylogeny; D013045:Species Specificity