TY - JOUR
T1 - A tangled tale of two teal
T2 - Population history of the grey Anas gracilis and chestnut teal a. castanea of Australia
AU - Joseph, Leo
AU - Adcock, Gregory J.
AU - Linde, Celeste
AU - Omland, Kevin E.
AU - Heinsohn, Robert
AU - Terry Chesser, R.
AU - Roshier, David
PY - 2009/7
Y1 - 2009/7
N2 - Two Australian species of teal (Anseriformes: Anatidae: Anas), the grey teal Anas gracilis and the chestnut teal A. castanea, are remarkable for the zero or near-zero divergence recorded between them in earlier surveys of mitochondrial DNA (mtDNA) diversity. We confirmed this result through wider geographical and population sampling as well as nucleotide sampling in the more rapidly evolving mtDNA control region. Any data set where two species share polymorphism as is the case here can be explained by a model of gene flow through hybridization on one hand or by incomplete lineage sorting on the other hand. Ideally, analysis of such shared polymorphism would simultaneously estimate the likelihood of both phenomena. To do this, we used the underlying principle of the IMa package to explore ramifications to understanding population histories of A. gracilis and A. castanea. We cannot reject that hybridization occurs between the two species but an equally or more plausible finding for their nearly zero divergence is incomplete sorting following very recent divergence between the two, probably in the mid-late Pleistocene. Our data add to studies that explore intermediate stages in the evolution of reciprocal monophyly and paraphyletic or polyphyletic relationships in mtDNA diversity among widespread Australian birds.
AB - Two Australian species of teal (Anseriformes: Anatidae: Anas), the grey teal Anas gracilis and the chestnut teal A. castanea, are remarkable for the zero or near-zero divergence recorded between them in earlier surveys of mitochondrial DNA (mtDNA) diversity. We confirmed this result through wider geographical and population sampling as well as nucleotide sampling in the more rapidly evolving mtDNA control region. Any data set where two species share polymorphism as is the case here can be explained by a model of gene flow through hybridization on one hand or by incomplete lineage sorting on the other hand. Ideally, analysis of such shared polymorphism would simultaneously estimate the likelihood of both phenomena. To do this, we used the underlying principle of the IMa package to explore ramifications to understanding population histories of A. gracilis and A. castanea. We cannot reject that hybridization occurs between the two species but an equally or more plausible finding for their nearly zero divergence is incomplete sorting following very recent divergence between the two, probably in the mid-late Pleistocene. Our data add to studies that explore intermediate stages in the evolution of reciprocal monophyly and paraphyletic or polyphyletic relationships in mtDNA diversity among widespread Australian birds.
UR - http://www.scopus.com/inward/record.url?scp=67749093560&partnerID=8YFLogxK
U2 - 10.1111/j.1600-048X.2008.04652.x
DO - 10.1111/j.1600-048X.2008.04652.x
M3 - Article
SN - 0908-8857
VL - 40
SP - 430
EP - 439
JO - Journal of Avian Biology
JF - Journal of Avian Biology
IS - 4
ER -