title: Extinction as a driver of avian latitudinal diversity gradients.
abstract: The role of historical factors in driving latitudinal diversity gradients is poorly understood. Here, we used an updated global phylogeny of terrestrial birds to test the role of three key historical factors-speciation, extinction, and dispersal rates-in generating latitudinal diversity gradients for eight major clades. We fit a model that allows speciation, extinction, and dispersal rates to differ, both with latitude and between the New and Old World. Our results consistently support extinction (all clades had lowest extinction where species richness was highest) as a key driver of species richness gradients across each of eight major clades. In contrast, speciation and dispersal rates showed no consistent latitudinal patterns across replicate bird clades, and thus are unlikely to represent general underlying drivers of latitudinal diversity gradients.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada. p.pulidosantacruz@mail.utoronto.ca.
authors.forename: Paola
authors.initials: P
authors.lastname: Pulido-Santacruz
authors.affiliation: Current Address: Department of Ecology and Evolutionary Biology, University of Toronto, 1265 Military Trail, Scarborough, Ontario, M1C 1A4, Canada.|Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Weir
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D044822:Biodiversity; D001717:Birds / Q000145:classification*; D053476:Extinction, Biological; D049810:Genetic Speciation; D005843:Geography; D008957:Models, Genetic; D010802:Phylogeny
keywords: Birds; extinction rate; historical factors; latitudinal diversity gradients; speciation rate; species richness