Birds of Indian Subcontinent

Mitochondrial DNA Phylogeographic Differentiation among Avian Populations and the Evolutionary Significance of Subspecies

Publication Type:Journal Article
Year of Publication:1992
Authors:R. Ball, Jr., M, AVISE, JOHNC
Journal:The Auk
Date Published:1992
ISBN Number:00048038
Keywords:Columba, Columba palumbus, Columbidae, Dryobates, Dryobates pubescens, Emberizidae, Geothlypis, Geothlypis trichas, Icteridae, Melospiza, Melospiza melodia, Molothrus, Molothrus ater, Parulidae, Passerella, Passerella melodia, Picidae, Picoides, Picoides pubescens, Pipilo, Pipilo erythrophthalmus, Pipilo maculatus, Trichas, Zenaida, Zenaida macroura, Zenaidura, Zenaidura macroura, Zonotrichia, Zonotrichia melodia
Abstract:Phylogeographic population structures revealed by restriction analyses of mitochondrial (mt) DNA were assessed within each of six avian species with continentwide distributions in North America. The magnitude and geographic pattern of mtDNA variation differed considerably among species. The Downy Woodpecker (Picoides pubescens) and Mourning Dove (Zenaida macroura) exhibited little mtDNA polymorphism and a shallow phylogeographic structure. The Brown-headed Cowbird (Molothrus ater) and Song Sparrow (Melospiza melodia) showed somewhat higher nucleotide diversity, but no evidence of long-standing population separations. For each of these four species, evolutionary effective sizes of female populations estimated from mtDNA were substantially smaller than population sizes at the present time, suggesting historical demographic constraints on the numbers of females through which mtDNA lineages successfully have been transmitted. In contrast, the Rufous-sided Towhee (Pipilo erythrophthalmus) and Common Yellowthroat (Geothlypis trichas) showed relatively deep mtDNA separations (mean nucleotide sequence divergence p = 0.008 and p = 0.012, respectively) between populations in Washington versus those in the central and eastern states. In the case of the Rufous-sided Towhee, the mtDNA clades may correspond to morphological and behavioral differences distinguishing the western "Spotted Towhee," which was formerly recognized as a distinct species. Overall, however, most of the taxonomic subspecies currently recognized within the six assayed species were genetically very close, and showed no obvious mtDNA differences. These results raise questions concerning the population-genetic and evolutionary significance of current subspecies designations in ornithology.
Short Title:The Auk
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith