title: Marked phylogeographic structure of Gentoo penguin reveals an ongoing diversification process along the Southern Ocean.
abstract: Two main hypotheses have been debated about the biogeography of the Southern Ocean: (1) the Antarctic Polar Front (APF), acting as a barrier between Antarctic and sub-Antarctic provinces, and (2) the Antarctic Circumpolar Current (ACC), promoting gene flow among sub-Antarctic areas. The Gentoo penguin is distributed throughout these two provinces, separated by the APF. We analyzed mtDNA (HVR1) and 12 microsatellite loci of 264 Gentoo penguins, Pygoscelis papua, from 12 colonies spanning from the Western Antarctic Peninsula and the South Shetland Islands (WAP) to the sub-Antarctic Islands (SAI). While low genetic structure was detected among WAP colonies (mtDNA ФST=0.037-0.133; microsatellite FST=0.009-0.063), high differentiation was found between all SAI and WAP populations (mtDNA ФST=0.678-0.930; microsatellite FST=0.110-0.290). These results suggest that contemporary dispersal around the Southern Ocean is very limited or absent. As predicted, the APF appears to be a significant biogeographical boundary for Gentoo penguin populations; however, the ACC does not promote connectivity in this species. Our data suggest demographic expansion in the WAP during the last glacial maximum (LGM, about 20kya), but stability in SAI. Phylogenetic analyses showed a deep divergence between populations from the WAP and those from the SAI. Therefore, taxonomy should be further revised. The Crozet Islands resulted as a basal clade (3.57Mya), followed by the Kerguelen Islands (2.32Mya) as well as a more recent divergence between the Falkland/Malvinas Islands and the WAP (1.27Mya). Historical isolation, local adaptation, and past climate scenarios of those Evolutionarily Significant Units may have led to different potentials to respond to climate changes.
authors.affiliation: Pontificia Universidad Católica de Chile, Departamento de Ecosistemas y Medio Ambiente, Vicuña Mackenna 4860, Macul, Santiago, Chile. Electronic address: jvianna@uc.cl.
authors.forename: Juliana A
authors.initials: JA
authors.lastname: Vianna
authors.affiliation: Pontificia Universidad Católica de Chile, Departamento de Ecosistemas y Medio Ambiente, Vicuña Mackenna 4860, Macul, Santiago, Chile.
authors.forename: Daly
authors.initials: D
authors.lastname: Noll
authors.affiliation: Pontificia Universidade Católica de Minas Gerais, PPG in Vertebrate Zoology, Belo Horizonte, Brazil.
authors.forename: Gisele P M
authors.initials: GPM
authors.lastname: Dantas
authors.affiliation: Universidade do Vale do Rio dos Sinos, Laboratório de Ornitologia e Animais Marinhos, Av. Unisinos, 950, São Leopoldo, RS, Brazil.
authors.forename: Maria Virginia
authors.initials: MV
authors.lastname: Petry
authors.affiliation: Museo Nacional de Ciencias Naturales, Departamento de Ecología Evolutiva, CSIC, C/José Gutiérrez Abascal, 2, 28006 Madrid, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Barbosa
authors.affiliation: Universidad de Concepción, Departamento de Ciencias Pecuarias, Facultad de Ciencias Veterinarias, Av. Vicente Méndez 595, CP 3780000 Chillán, Chile.
authors.forename: Daniel
authors.initials: D
authors.lastname: González-Acuña
authors.affiliation: Université de Strasbourg (UdS), Institut Pluridisciplinaire Hubert Curien, Laboratoire International Associé LIA-647 BioSensib (CSM-CNRS-UdS), 23 rue Becquerel, 67087 Strasbourg Cedex 02, France; Centre National de la Recherche Scientifique (CNRS), UMR 7178, LIA-647 BioSensib, 23 rue Becquerel, 67087 Strasbourg Cedex 02, France; Centre Scientifique de Monaco (CSM), LIA-647 BioSensib, 8 quai Antoine 1er, MC 98000, Monaco.
authors.forename: Céline
authors.initials: C
authors.lastname: Le Bohec
authors.affiliation: CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 route de Mende, 34293 Montpellier cedex 5, France.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bonadonna
authors.affiliation: Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Universidad de Chile, Santiago, Chile.
authors.forename: Elie
authors.initials: E
authors.lastname: Poulin
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D003710:Demography; D014644:Genetic Variation; D005828:Genetics, Population; D018895:Microsatellite Repeats / Q000235:genetics; D009792:Oceans and Seas; D010802:Phylogeny; D058974:Phylogeography; D011336:Probability; D046429:Spheniscidae / Q000145:classification*
chemical_list: D004272:DNA, Mitochondrial
keywords: Climate change; Demographic history; Polar region; Population structure; Seabirds