Parrot evolution and paleogeographical events: Mitochondrial DNA evidence

Abstract

We sequenced 1,771 bp of three mitochondrial genes (12S rDNA, 16S rDNA, and cytochrome b) of nine New World parrot genera (Amazona aestiva, Anodorhynchus hyacinthinus, Ara ararauna, Aratinga aurea, Cyanopsitta spixii, Deroptyus accipitrinus, Guaruba guarouba, Pionus menstruus, and Pyrrhura picta) and compared them with the corresponding sequence of Australian parakeet (Melopsittacus undulatus). Phylogenetic analyses (maximum parsimony and maximum likelihood) showed that the Neotropical species we studied constitute two monophyletic groups: the long-tailed and the short-tailed species. The separation within the long-tailed species could be assigned to the late Oligocene-early Miocene, when paleoenvironmental changes might have influenced this radiation. The long-tailed Neotropical and Australasian species diverged during the Cretaceous-Tertiary boundary, when South America and Australia were moving away from Antarctica (Gondwanaland fission). We also compared our data with the cytochrome b sequences of seven different genera of Australasian parrots obtained by other investigators, and these comparisons also support the independent evolution of the Neotropical and Australasian species. Analyses performed with 567 bp of partial sequences of 12S rDNA and cytochrome b did not support or refute the hypothesis of monophyly of the Neotropical parrots with respect to an African species whose sequences were available. However, this analysis supported the view that the divergence between Neotropical short- and long-tailed taxa was older than the Oligocene-Miocene divergence among the long-tailed genera.