title: Parallel radiations in the primary clades of birds.
abstract: Knowledge of avian phylogeny is prerequisite to understanding the circumstances and timing of the diversification of birds and the evolution of morphological, behavioral, and life-history traits. Recent molecular datasets have helped to elucidate the three most basal clades in the tree of living birds, but relationships among neoavian orders (the vast majority of birds) remain frustratingly vexing. Here, we examine intron 7 of the beta-fibrinogen gene in the most taxonomically inclusive survey of DNA sequences of nonpasserine bird families and orders to date. These data suggest that Neoaves consist of two sister clades with ecological parallelisms comparable to those found between marsupial and placental mammals. Some members of the putative respective clades have long been recognized as examples of convergent evolution, but it was not appreciated that they might be parts of diverse parallel radiations. In contrast, some traditional orders of birds are suggested by these data to be polyphyletic, with representative families in both radiations.
authors.affiliation: Department of Biology, New Mexico State University, Box 30001, MSC 3AF, Las Cruces, New Mexico 88003, USA. mfain@nmsu.edu
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Fain
authors.forename: Peter
authors.initials: P
authors.lastname: Houde
mesh_terms: D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D001717:Birds / Q000033:anatomy & histology / Q000235:genetics*; D016000:Cluster Analysis; D017931:DNA Primers; D005340:Fibrinogen / Q000235:genetics; D005843:Geography; D007438:Introns / Q000235:genetics; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D005340:Fibrinogen