title: Rapid diversification of falcons (Aves: Falconidae) due to expansion of open habitats in the Late Miocene.
abstract: Understanding how and why lineages diversify is central to understanding the origins of biological diversity. The avian family Falconidae (caracaras, forest-falcons, falcons) has an uneven distribution of species among multiple well-supported clades, and provides a useful system for testing hypotheses about diversification rate and correlation with environmental changes. We analyzed eight independent loci for 1-7 individuals from each of the 64 currently recognized Falconidae species, together with two fossil falconid temporal calibrations, to assess phylogeny, absolute divergence times and potential shifts in diversification rate. Our analyses supported similar diversification ages in the Early to Middle Miocene for the three traditional subfamilies, Herpetotherinae, Polyborinae and Falconinae. We estimated that divergences within the subfamily Falconinae began about 16mya and divergences within the most species-rich genus, Falco, including about 60% of all Falconidae species, began about 7.5mya. We found evidence for a significant increase in diversification rate at the basal phylogenetic node for the genus Falco, and the timing for this rate shift correlates generally with expansion of C4 grasslands beginning around the Miocene/Pliocene transition. Concomitantly, Falco lineages that are distributed primarily in grassland or savannah habitats, as opposed to woodlands, and exhibit migratory, as opposed to sedentary, behavior experienced a higher diversification rate.
authors.affiliation: Department of Ornithology and Mammalogy, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, United States; UMR7205, Institut de Systématique, Evolution, Biodiversité, CNRS MNHN UPMC EPHE, Département Systématique et Evolution, Muséum National d'Histoire Naturelle, 57 Rue cuvier, Case Postale 51, F-75231 Paris Cedex 05, France; UMS MNHN/CNRS 2700, Outils et Méthodes de la Systématique Intégrative (OMSI), Muséum National d'Histoire Naturelle, 57 rue Cuvier, F-75231 Paris Cedex 05, France. Electronic address: fuchs@mnhn.fr.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Fuchs
authors.affiliation: Department of Biological Sciences, Institute of Applied Sciences, University of North Texas, 1155 Union Circle #310559, Denton, TX 76203, United States.
authors.forename: Jeff A
authors.initials: JA
authors.lastname: Johnson
authors.affiliation: Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, CA 94158, United States; Division of Environmental Biology, National Science Foundation, 4201 Wilson Blvd., Arlington, VA 22230, United States.
authors.forename: David P
authors.initials: DP
authors.lastname: Mindell
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D044822:Biodiversity; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D046093:Falconiformes / Q000145:classification*; D005580:Fossils; D049810:Genetic Speciation; D016013:Likelihood Functions; D008957:Models, Genetic; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: Diversification rates; Falco; Falconidae; Habitat; Migratory behavior; Miocene