MBE Advance Access originally published online on July 24, 2008
Molecular Biology and Evolution 2008 25(10):2141-2156; doi:10.1093/molbev/msn160
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Research Articles |
A Multilocus Molecular Phylogeny of the Parrots (Psittaciformes): Support for a Gondwanan Origin during the Cretaceous
* Department of Biology, New Mexico State University, Las Cruces, NM
Genetics Program, National Museum of Natural History & National Zoological Park, Smithsonian Institution, Washington, DC
Departmento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, SP, Brasil
Department of Biology and Museum of Natural Science, Louisiana State University
|| Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC
¶ National Institute of Toxicology and Forensic Science, Tenerife, Spain
# Department of Veterinary Medicine, Loro Parque Fundación, Puerto de la Cruz, Tenerife, Spain
** School of Biological Sciences, Victoria University, Wellington, New Zealand
E-mail: wright{at}nmsu.edu.
Accepted for publication July 18, 2008.
The question of when modern birds (Neornithes) first diversified has generated much debate among avian systematists. Fossil evidence generally supports a Tertiary diversification, whereas estimates based on molecular dating favor an earlier diversification in the Cretaceous period. In this study, we used an alternate approach, the inference of historical biogeographic patterns, to test the hypothesis that the initial radiation of the Order Psittaciformes (the parrots and cockatoos) originated on the Gondwana supercontinent during the Cretaceous. We utilized broad taxonomic sampling (representatives of 69 of the 82 extant genera and 8 outgroup taxa) and multilocus molecular character sampling (3,941 bp from mitochondrial DNA (mtDNA) genes cytochrome oxidase I and NADH dehydrogenase 2 and nuclear introns of rhodopsin intron 1, tropomyosin alpha-subunit intron 5, and transforming growth factor ß-2) to generate phylogenetic hypotheses for the Psittaciformes. Analyses of the combined character partitions using maximum parsimony, maximum likelihood, and Bayesian criteria produced well-resolved and topologically similar trees in which the New Zealand taxa Strigops and Nestor (Psittacidae) were sister to all other psittaciforms and the cockatoo clade (Cacatuidae) was sister to a clade containing all remaining parrots (Psittacidae). Within this large clade of Psittacidae, some traditionally recognized tribes and subfamilies were monophyletic (e.g., Arini, Psittacini, and Loriinae), whereas several others were polyphyletic (e.g., Cyclopsittacini, Platycercini, Psittaculini, and Psittacinae). Ancestral area reconstructions using our Bayesian phylogenetic hypothesis and current distributions of genera supported the hypothesis of an Australasian origin for the Psittaciformes. Separate analyses of the timing of parrot diversification constructed with both Bayesian relaxed-clock and penalized likelihood approaches showed better agreement between geologic and diversification events in the chronograms based on a Cretaceous dating of the basal split within parrots than the chronograms based on a Tertiary dating of this split, although these data are more equivocal. Taken together, our results support a Cretaceous origin of Psittaciformes in Gondwana after the separation of Africa and the India/Madagascar block with subsequent diversification through both vicariance and dispersal. These well-resolved molecular phylogenies will be of value for comparative studies of behavior, ecology, and life history in parrots.
Key Words: Cretaceous origin • divergence times • Gondwanan distribution • K/T boundary • molecular phylogeny • parrot • Psittaciformes • Tertiary origin
Hervé Philippe, Associate Editor