1
|
Abstract
Many species of plants, animals, and microorganisms exchange genes well after the point of evolutionary divergence at which taxonomists recognize them as species. Genomes contain signatures of past gene exchange and, in some cases, they reveal a legacy of lineages that no longer exist. But genomic data are not available for many organisms, and particularly problematic for reconstructing and interpreting evolutionary history are communities that have been depleted by extinctions. For these, morphology may substitute for genes, as exemplified by the history of Darwin's finches on the Galápagos islands of Floreana and San Cristóbal. Darwin and companions collected seven specimens of a uniquely large form of Geospiza magnirostris in 1835. The populations became extinct in the next few decades, partly due to destruction of Opuntia cactus by introduced goats, whereas Geospiza fortis has persisted to the present. We used measurements of large samples of G. fortis collected for museums in the period 1891 to 1906 to test for unusually large variances and skewed distributions of beak and body size resulting from introgression. We found strong evidence of hybridization on Floreana but not on San Cristóbal. The skew is in the direction of the absent G. magnirostris We estimate introgression influenced 6% of the frequency distribution that was eroded by selection after G. magnirostris became extinct on these islands. The genetic residuum of an extinct species in an extant one has implications for its future evolution, as well as for a conservation program of reintroductions in extinction-depleted communities.
Collapse
|
2
|
Graham AM, Peters JL, Wilson RE, Muñoz-Fuentes V, Green AJ, Dorfsman DA, Valqui TH, Winker K, McCracken KG. Adaptive introgression of the beta-globin cluster in two Andean waterfowl. Heredity (Edinb) 2021; 127:107-123. [PMID: 33903741 PMCID: PMC8249413 DOI: 10.1038/s41437-021-00437-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 04/04/2021] [Accepted: 04/08/2021] [Indexed: 11/09/2022] Open
Abstract
Introgression of beneficial alleles has emerged as an important avenue for genetic adaptation in both plant and animal populations. In vertebrates, adaptation to hypoxic high-altitude environments involves the coordination of multiple molecular and cellular mechanisms, including selection on the hypoxia-inducible factor (HIF) pathway and the blood-O2 transport protein hemoglobin (Hb). In two Andean duck species, a striking DNA sequence similarity reflecting identity by descent is present across the ~20 kb β-globin cluster including both embryonic (HBE) and adult (HBB) paralogs, though it was yet untested whether this is due to independent parallel evolution or adaptive introgression. In this study, we find that identical amino acid substitutions in the β-globin cluster that increase Hb-O2 affinity have likely resulted from historical interbreeding between high-altitude populations of two different distantly-related species. We examined the direction of introgression and discovered that the species with a deeper mtDNA divergence that colonized high altitude earlier in history (Anas flavirostris) transferred adaptive genetic variation to the species with a shallower divergence (A. georgica) that likely colonized high altitude more recently possibly following a range shift into a novel environment. As a consequence, the species that received these β-globin variants through hybridization might have adapted to hypoxic conditions in the high-altitude environment more quickly through acquiring beneficial alleles from the standing, hybrid-origin variation, leading to faster evolution.
Collapse
Affiliation(s)
- Allie M Graham
- Eccles Institute for Human Genetics, University of Utah, Salt Lake City, UT, USA.
| | - Jeffrey L Peters
- Department of Biological Sciences, Wright State University, Dayton, OH, USA
| | - Robert E Wilson
- School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Violeta Muñoz-Fuentes
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, UK
| | - Andy J Green
- Department of Wetland Ecology, Estación Biológica de Doñana, EBD-CSIC, Sevilla, Spain
| | - Daniel A Dorfsman
- Human Genetics and Genomics, Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Thomas H Valqui
- Centro de Ornitología y Biodiversidad (CORBIDI), Surco, Lima, Perú
- Universidad Nacional Agraria, La Molina, Perú
| | - Kevin Winker
- University of Alaska Museum and Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Kevin G McCracken
- Human Genetics and Genomics, Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA.
- Centro de Ornitología y Biodiversidad (CORBIDI), Surco, Lima, Perú.
- University of Alaska Museum and Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.
- Department of Biology, University of Miami, Coral Gables, FL, USA.
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL, USA.
| |
Collapse
|
3
|
Storz JF, Signore AV. Introgressive Hybridization and Hypoxia Adaptation in High-Altitude Vertebrates. Front Genet 2021; 12:696484. [PMID: 34239546 PMCID: PMC8258166 DOI: 10.3389/fgene.2021.696484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 05/25/2021] [Indexed: 11/13/2022] Open
Abstract
In natural populations of animals, a growing body of evidence suggests that introgressive hybridization may often serve as an important source of adaptive genetic variation. Population genomic studies of high-altitude vertebrates have provided strong evidence of positive selection on introgressed allelic variants, typically involving a long-term highland species as the donor and a more recently arrived colonizing species as the recipient. In high-altitude humans and canids from the Tibetan Plateau, case studies of adaptive introgression involving the HIF transcription factor, EPAS1, have provided insights into complex histories of ancient introgression, including examples of admixture from now-extinct source populations. In Tibetan canids and Andean waterfowl, directed mutagenesis experiments involving introgressed hemoglobin variants successfully identified causative amino acid mutations and characterized their phenotypic effects, thereby providing insights into the functional properties of selectively introgressed alleles. We review case studies of adaptive introgression in high-altitude vertebrates and we highlight findings that may be of general significance for understanding mechanisms of environmental adaptation involving different sources of genetic variation.
Collapse
Affiliation(s)
- Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln, NE, United States
| | - Anthony V Signore
- School of Biological Sciences, University of Nebraska, Lincoln, NE, United States
| |
Collapse
|
4
|
Shizuka D, Hudson EJ. To accept or reject heterospecific mates: behavioural decisions underlying premating isolation. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190484. [PMID: 32420857 DOI: 10.1098/rstb.2019.0484] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Premating isolation in animals involves decision-making processes that affect whether individuals accept or reject heterospecific mates. An integrative understanding of the behavioural processes underlying heterospecific acceptance can clarify the conditions under which premating isolation evolves. As an illustration, we review how Reeve's (Reeve 1989 Am. Nat. 133, 407-435. (doi:10.1086/284926)) acceptance threshold model can help make sense of patterns of premating isolation in nature. This model derives a threshold trait value for acceptance for rejection of recipients of an action (e.g. mating) based on the fitness consequences of these decisions. We show that the maintenance of partial reproductive isolation can be an outcome of optimal acceptance thresholds, even in the face of reinforcement. We also use this model to clarify how the composition of multispecies communities can shape premating isolation. The acceptance threshold model can also be viewed as the behavioural underpinning of reproductive character displacement and cascading reinforcement. Finally, we highlight potential limitations of the acceptance threshold model with respect to investigating the role of sexual selection in speciation, and we propose that integration of behavioural models in speciation research will help us gain a full picture of the mechanisms underlying premating isolation. This article is part of the theme issue 'Signal detection theory in recognition systems: from evolving models to experimental tests'.
Collapse
Affiliation(s)
- Daizaburo Shizuka
- School of Biological Sciences, University of Nebraska-Lincoln, 402 Manter Hall, Lincoln, NE 68588-0118, USA
| | - Emily J Hudson
- School of Biological Sciences, University of Nebraska-Lincoln, 402 Manter Hall, Lincoln, NE 68588-0118, USA.,Department of Biological Sciences, Vanderbilt University, Box 351634 Station B, Nashville, TN 37235-1634, USA
| |
Collapse
|
5
|
Wells CP, Lavretsky P, Sorenson MD, Peters JL, DaCosta JM, Turnbull S, Uyehara KJ, Malachowski CP, Dugger BD, Eadie JM, Engilis A. Persistence of an endangered native duck, feral mallards, and multiple hybrid swarms across the main Hawaiian Islands. Mol Ecol 2019; 28:5203-5216. [DOI: 10.1111/mec.15286] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Caitlin P. Wells
- Department of Wildlife, Fish, and Conservation Biology University of California Davis CA USA
| | - Philip Lavretsky
- Department of Biological Sciences University of Texas El Paso TX USA
| | | | - Jeffrey L. Peters
- Department of Biological Sciences Wright State University Dayton OH USA
| | | | - Stephen Turnbull
- Division of Forestry and Wildlife Department of Land and Natural Resources Honolulu HI USA
| | - Kimberly J. Uyehara
- Kauaʻi National Wildlife Refuge Complex U.S. Fish and Wildlife Service Kīlauea HI USA
| | | | - Bruce D. Dugger
- Department of Fisheries and Wildlife Oregon State University Corvallis OR USA
| | - John M. Eadie
- Department of Wildlife, Fish, and Conservation Biology University of California Davis CA USA
| | - Andrew Engilis
- Department of Wildlife, Fish, and Conservation Biology University of California Davis CA USA
- Museum of Wildlife and Fish Biology University of California Davis CA USA
| |
Collapse
|
6
|
Päckert M, Ait Belkacem A, Wolfgramm H, Gast O, Canal D, Giacalone G, Lo Valvo M, Vamberger M, Wink M, Martens J, Stuckas H. Genetic admixture despite ecological segregation in a North African sparrow hybrid zone (Aves, Passeriformes, Passer domesticus × Passer hispaniolensis). Ecol Evol 2019; 9:12710-12726. [PMID: 31788209 PMCID: PMC6875665 DOI: 10.1002/ece3.5744] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/30/2019] [Accepted: 09/02/2019] [Indexed: 11/29/2022] Open
Abstract
Under different environmental conditions, hybridization between the same species might result in different patterns of genetic admixture. Particularly, species pairs with large distribution ranges and long evolutionary history may have experienced several independent hybridization events over time in different zones of overlap. In birds, the diverse hybrid populations of the house sparrow (Passer domesticus) and the Spanish sparrow (Passer hispaniolensis) provide a striking example. Throughout their range of sympatry, these two species do not regularly interbreed; however, a stabilized hybrid form (Passer italiae) exists on the Italian Peninsula and on several Mediterranean islands. The spatial distribution pattern on the Eurasian continent strongly contrasts the situation in North Africa, where house sparrows and Spanish sparrows occur in close vicinity of phenotypically intermediate populations across a broad mosaic hybrid zone. In this study, we investigate patterns of divergence and admixture among the two parental species, stabilized and nonstabilized hybrid populations in Italy and Algeria based on a mitochondrial marker, a sex chromosomal marker, and 12 microsatellite loci. In Algeria, despite strong spatial and temporal separation of urban early-breeding house sparrows and hybrids and rural late-breeding Spanish sparrows, we found strong genetic admixture of mitochondrial and nuclear markers across all study populations and phenotypes. That pattern of admixture in the North African hybrid zone is strikingly different from i) the Iberian area of sympatry where we observed only weak asymmetrical introgression of Spanish sparrow nuclear alleles into local house sparrow populations and ii) the very homogenous Italian sparrow population where the mitogenome of one parent (P. domesticus) and the Z-chromosomal marker of the other parent (P. hispaniolensis) are fixed. The North African sparrow hybrids provide a further example of enhanced hybridization along with recent urbanization and anthropogenic land-use changes in a mosaic landscape.
Collapse
Affiliation(s)
- Martin Päckert
- Senckenberg Naturhistorische Sammlungen Dresden, Senckenberg|Leibniz Institution for Biodiversity and Earth System ResearchDresdenGermany
| | - Abdelkrim Ait Belkacem
- Laboratoire d'Exploration et de Valorisation des Écosystèmes SteppiquesFaculté des Sciences de la nature et de la vieUniversité de DjelfaDjelfaAlgeria
| | - Hannes Wolfgramm
- Senckenberg Naturhistorische Sammlungen Dresden, Senckenberg|Leibniz Institution for Biodiversity and Earth System ResearchDresdenGermany
| | - Oliver Gast
- Institute of Vertebrate Biology Brno & Masaryk University BrnoBrnoCzech Republic
| | - David Canal
- Department of Evolutionary EcologyEstación Biológica de Doñana—CSICSevilleSpain
- Centro para el Estudio y Conservación de las Aves Rapaces en Argentina (CECARA‐UNLPam) & Instituto de las Ciencias de la Tierra y Ambientales de La Pampa (INCITAP)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Santa RosaArgentina
| | | | - Mario Lo Valvo
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e FarmaceuticheUniversità degli Studi di PalermoPalermoItaly
| | - Melita Vamberger
- Senckenberg Naturhistorische Sammlungen Dresden, Senckenberg|Leibniz Institution for Biodiversity and Earth System ResearchDresdenGermany
| | - Michael Wink
- Department of BiologyInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Jochen Martens
- Institute of Organismic and Molecular EvolutionJohannes Gutenberg UniversityMainzGermany
| | - Heiko Stuckas
- Senckenberg Naturhistorische Sammlungen Dresden, Senckenberg|Leibniz Institution for Biodiversity and Earth System ResearchDresdenGermany
| |
Collapse
|
7
|
Wang W, Wang Y, Lei F, Liu Y, Wang H, Chen J. Incomplete lineage sorting and introgression in the diversification of Chinese spot-billed ducks and mallards. Curr Zool 2019; 65:589-597. [PMID: 31616490 PMCID: PMC6784501 DOI: 10.1093/cz/zoy074] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 10/10/2018] [Indexed: 11/21/2022] Open
Abstract
Incomplete lineage sorting and introgression are 2 major and nonexclusive causes of species-level non-monophyly. Distinguishing between these 2 processes is notoriously difficult because they can generate similar genetic signatures. Previous studies have suggested that 2 closely related duck species, the Chinese spot-billed duck Anas zonorhyncha and the mallard A. platyrhynchos were polyphyletically intermixed. Here, we utilized a wide geographical sampling, multilocus data and a coalescent-based model to revisit this system. Our study confirms the finding that Chinese spot-billed ducks and Mallards are not monophyletic. There was no apparent interspecific differentiation across loci except those at the mitochondrial DNA (mtDNA) control region and the Z chromosome (CHD1Z). Based on an isolation-with-migration model and the geographical distribution of lineages, we suggest that both introgression and incomplete lineage sorting might contribute to the observed non-monophyly of the 2 closely related duck species. The mtDNA introgression was asymmetric, with high gene flow from Chinese spot-billed ducks to Mallards and negligible gene flow in the opposite direction. Given that the 2 duck species are phenotypically distinctive but weakly genetically differentiated, future work based on genome-scale data is necessary to uncover genomic regions that are involved in divergence, and this work may provide further insights into the evolutionary histories of the 2 species and other waterfowls.
Collapse
Affiliation(s)
- Wenjuan Wang
- Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Center for Watershed Ecology, Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
- Institute of Biodiversity Science, Fudan University, Shanghai, China
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, China
- National Ecosystem Research Station of Jiangxi Poyang Lake Wetland, Nanchang, China
| | - Yafang Wang
- Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Center for Watershed Ecology, Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Fumin Lei
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yang Liu
- State Key Laboratory of Biocontrol, Department of Ecology/School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Haitao Wang
- Jilin Provincial Engineering Laboratory of Avian Ecology and Conservation Genetics, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Jiakuan Chen
- Institute of Biodiversity Science, Fudan University, Shanghai, China
| |
Collapse
|
8
|
Oliveira T, Urra F, López‐Martín JM, Ballesteros‐Duperón E, Barea‐Azcón JM, Moléon M, Gil‐Sánchez JM, Alves PC, Díaz‐Ruíz F, Ferreras P, Monterroso P. Females know better: Sex-biased habitat selection by the European wildcat. Ecol Evol 2018; 8:9464-9477. [PMID: 30377515 PMCID: PMC6194279 DOI: 10.1002/ece3.4442] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 01/13/2018] [Accepted: 07/06/2018] [Indexed: 02/05/2023] Open
Abstract
The interactions between animals and their environment vary across species, regions, but also with gender. Sex-specific relations between individuals and the ecosystem may entail different behavioral choices and be expressed through different patterns of habitat use. Regardless, only rarely sex-specific traits are addressed in ecological modeling approaches. The European wildcat (Felis silvestris silvestris) is a species of conservation concern in Europe, with a highly fragmented and declining distribution across most of its range. We assessed sex-specific habitat selection patterns for the European wildcat, at the landscape and home range levels, across its Iberian biogeographic distribution using a multipopulation approach. We developed resource selection functions in a use-availability framework using radio-telemetry data from five wildcat populations. At the landscape level, we observed that, while both genders preferentially established home ranges in areas close to broadleaf forests and far from humanized areas, females selected mid-range elevation areas with some topographic complexity, whereas males used lowland areas. At the home range level, both females and males selected areas dominated by scrublands or broadleaf forests, but habitat features were less important at this level. The strength of association to habitat features was higher for females at both spatial levels, suggesting a tendency to select habitats with higher quality that can grant them enhanced access to shelter and feeding resources. Based on our results, we hypothesize that sex-biased behavioral patterns may contribute to the resilience of wildcats' genetic integrity through influencing the directionality of hybridization with domestic cats. Our study provides information about European wildcats' habitat use in an Iberian context, relevant for the implementation of conservation plans, and highlights the ecological relevance of considering sex-related differences in environmental preferences.
Collapse
Affiliation(s)
- Teresa Oliveira
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
- Departamento de BiologiaFaculdade de CiênciasUniversidade do PortoPortoPortugal
| | - Fermín Urra
- Gestión Ambiental de NavarraPamplonaNavarraSpain
| | - José María López‐Martín
- Secció d'Activitats Cinegètiques i Pesca ContinentalServeis Territorials de BarcelonaDepartment of D'Agricultura, Ramaderia, Pesca i AlimentacióGeneralitat de CatalunyaBarcelonaSpain
- Wildlife Ecology and Health GroupFacultat de VeterinàriaUniversitat Autònoma de Barcelona (UAB)BellaterraBarcelonaSpain
| | - Elena Ballesteros‐Duperón
- Agencia de Medio Ambiente y AguaConsejería de Medio Ambiente y Ordenación del TerritorioJunta de AndalucíaGranadaSpain
| | - José Miguel Barea‐Azcón
- Agencia de Medio Ambiente y AguaConsejería de Medio Ambiente y Ordenación del TerritorioJunta de AndalucíaGranadaSpain
| | - Marcos Moléon
- Department of ZoologyUniversity of GranadaGranadaSpain
| | | | - Paulo Celio Alves
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
- Departamento de BiologiaFaculdade de CiênciasUniversidade do PortoPortoPortugal
- Wildlife Biology ProgramUniversity of MontanaMissoulaMontana
| | - Francisco Díaz‐Ruíz
- Biogeography, Diversity and Conservation Research TeamDepartment of Animal BiologyFaculty of SciencesUniversity of MalagaMalagaSpain
| | - Pablo Ferreras
- Instituto de Investigación en Recursos Cinegéticos (IREC, CSIC‐UCLM‐JCCM)Ciudad RealSpain
| | - Pedro Monterroso
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
| |
Collapse
|
9
|
Graham AM, Lavretsky P, Muñoz-Fuentes V, Green AJ, Wilson RE, McCracken KG. Migration-Selection Balance Drives Genetic Differentiation in Genes Associated with High-Altitude Function in the Speckled Teal (Anas flavirostris) in the Andes. Genome Biol Evol 2018; 10:14-32. [PMID: 29211852 PMCID: PMC5757641 DOI: 10.1093/gbe/evx253] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2017] [Indexed: 12/30/2022] Open
Abstract
Local adaptation frequently occurs across populations as a result of migration-selection balance between divergent selective pressures and gene flow associated with life in heterogeneous landscapes. Studying the effects of selection and gene flow on the adaptation process can be achieved in systems that have recently colonized extreme environments. This study utilizes an endemic South American duck species, the speckled teal (Anas flavirostris), which has both high- and low-altitude populations. High-altitude speckled teal (A. f. oxyptera) are locally adapted to the Andean environment and mostly allopatric from low-altitude birds (A. f. flavirostris); however, there is occasional gene flow across altitudinal gradients. In this study, we used next-generation sequencing to explore genetic patterns associated with high-altitude adaptation in speckled teal populations, as well as the extent to which the balance between selection and migration have affected genetic architecture. We identified a set of loci with allele frequencies strongly correlated with altitude, including those involved in the insulin-like signaling pathway, bone morphogenesis, oxidative phosphorylation, responders to hypoxia-induced DNA damage, and feedback loops to the hypoxia-inducible factor pathway. These same outlier loci were found to have depressed gene flow estimates, as well as being highly concentrated on the Z-chromosome. Our results suggest a multifactorial response to life at high altitudes through an array of interconnected pathways that are likely under positive selection and whose genetic components seem to be providing an effective genomic barrier to interbreeding, potentially functioning as an avenue for population divergence and speciation.
Collapse
Affiliation(s)
| | | | - Violeta Muñoz-Fuentes
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- Estación Biológica de Doñana, EBD-CSIC, Sevilla, Spain
| | - Andy J Green
- Estación Biológica de Doñana, EBD-CSIC, Sevilla, Spain
| | - Robert E Wilson
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska, Fairbanks
| | - Kevin G McCracken
- Department of Biology, University of Miami
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska, Fairbanks
- Rosenstiel School of Marine and Atmospheric Sciences, University of Miami
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine
| |
Collapse
|
10
|
Booth Jones KA, Nicoll MAC, Raisin C, Dawson DA, Hipperson H, Horsburgh GJ, Groombridge JJ, Ismar SMH, Sweet P, Jones CG, Tatayah V, Ruhomaun K, Norris K. Widespread gene flow between oceans in a pelagic seabird species complex. Mol Ecol 2017; 26:5716-5728. [PMID: 28833786 DOI: 10.1111/mec.14330] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 08/02/2017] [Accepted: 08/07/2017] [Indexed: 12/15/2022]
Abstract
Global-scale gene flow is an important concern in conservation biology as it has the potential to either increase or decrease genetic diversity in species and populations. Although many studies focus on the gene flow between different populations of a single species, the potential for gene flow and introgression between species is understudied, particularly in seabirds. The only well-studied example of a mixed-species, hybridizing population of petrels exists on Round Island, in the Indian Ocean. Previous research assumed that Round Island represents a point of secondary contact between Atlantic (Pterodroma arminjoniana) and Pacific species (Pterodroma neglecta and Pterodroma heraldica). This study uses microsatellite genotyping and tracking data to address the possibility of between-species hybridization occurring outside the Indian Ocean. Dispersal and gene flow spanning three oceans were demonstrated between the species in this complex. Analysis of migration rates estimated using bayesass revealed unidirectional movement of petrels from the Atlantic and Pacific into the Indian Ocean. Conversely, structure analysis revealed gene flow between species of the Atlantic and Pacific oceans, with potential three-way hybrids occurring outside the Indian Ocean. Additionally, geolocation tracking of Round Island petrels revealed two individuals travelling to the Atlantic and Pacific. These results suggest that interspecific hybrids in Pterodroma petrels are more common than was previously assumed. This study is the first of its kind to investigate gene flow between populations of closely related Procellariiform species on a global scale, demonstrating the need for consideration of widespread migration and hybridization in the conservation of threatened seabirds.
Collapse
Affiliation(s)
- Katherine A Booth Jones
- Institute of Zoology, Zoological Society London, London, UK.,Department of Animal and Plant Sciences, NERC Biomolecular Analysis Facility, University of Sheffield, Sheffield, UK
| | | | - Claire Raisin
- Department of Animal and Plant Sciences, NERC Biomolecular Analysis Facility, University of Sheffield, Sheffield, UK.,Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, UK
| | - Deborah A Dawson
- Department of Animal and Plant Sciences, NERC Biomolecular Analysis Facility, University of Sheffield, Sheffield, UK
| | - Helen Hipperson
- Department of Animal and Plant Sciences, NERC Biomolecular Analysis Facility, University of Sheffield, Sheffield, UK
| | - Gavin J Horsburgh
- Department of Animal and Plant Sciences, NERC Biomolecular Analysis Facility, University of Sheffield, Sheffield, UK
| | - Jim J Groombridge
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, UK
| | - Stefanie M H Ismar
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Paul Sweet
- Division of Vertebrate Zoology - Ornithology, American Museum of Natural History, New York, NY, USA
| | - Carl G Jones
- Mauritian Wildlife Foundation, Vacoas, Mauritius.,Durrell Wildlife Conservation Trust, Channel Islands, UK
| | | | - Kevin Ruhomaun
- National Parks and Conservation Service (Government of Mauritius), Reduit, Mauritius
| | - Ken Norris
- Institute of Zoology, Zoological Society London, London, UK
| |
Collapse
|
11
|
Costa MC, Oliveira PRR, Davanço PV, de Camargo C, Laganaro NM, Azeredo RA, Simpson J, Silveira LF, Francisco MR. Recovering the Genetic Identity of an Extinct-in-the-Wild Species: The Puzzling Case of the Alagoas Curassow. PLoS One 2017; 12:e0169636. [PMID: 28056082 PMCID: PMC5215914 DOI: 10.1371/journal.pone.0169636] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 12/16/2016] [Indexed: 01/18/2023] Open
Abstract
The conservation of many endangered taxa relies on hybrid identification, and when hybrids become morphologically indistinguishable from the parental species, the use of molecular markers can assign individual admixture levels. Here, we present the puzzling case of the extinct in the wild Alagoas Curassow (Pauxi mitu), whose captive population descends from only three individuals. Hybridization with the Razor-billed Curassow (P. tuberosa) began more than eight generations ago, and admixture uncertainty affects the whole population. We applied an analysis framework that combined morphological diagnostic traits, Bayesian clustering analyses using 14 microsatellite loci, and mtDNA haplotypes to assess the ancestry of all individuals that were alive from 2008 to 2012. Simulated data revealed that our microsatellites could accurately assign an individual a hybrid origin until the second backcross generation, which permitted us to identify a pure group among the older, but still reproductive animals. No wild species has ever survived such a severe bottleneck, followed by hybridization, and studying the recovery capability of the selected pure Alagoas Curassow group might provide valuable insights into biological conservation theory.
Collapse
Affiliation(s)
- Mariellen C. Costa
- Programa de Pós Graduação em Ecologia e Recursos Naturais, Universidade Federal de São Carlos, Rod. Washington Luís, CEP, São Carlos, SP, Brazil
| | - Paulo R. R. Oliveira
- Programa de Pós Graduação em Diversidade Biológica e Conservação, Universidade Federal de São Carlos, campus de Sorocaba, Rod. João Leme dos Santos, CEP, Sorocaba, SP, Brazil
| | - Paulo V. Davanço
- Programa de Pós Graduação em Diversidade Biológica e Conservação, Universidade Federal de São Carlos, campus de Sorocaba, Rod. João Leme dos Santos, CEP, Sorocaba, SP, Brazil
| | - Crisley de Camargo
- Departamento de Ciências Ambientais, Universidade Federal de São Carlos, Campus de Sorocaba, Rod. João Leme dos Santos, CEP, Sorocaba, SP, Brazil
| | - Natasha M. Laganaro
- Programa de Pós Graduação em Diversidade Biológica e Conservação, Universidade Federal de São Carlos, campus de Sorocaba, Rod. João Leme dos Santos, CEP, Sorocaba, SP, Brazil
| | - Roberto A. Azeredo
- CRAX—Sociedade de Pesquisa do Manejo e da Reprodução da Fauna Silvestre, rua Jarbas Camargo, Chácara Campestre, Contagem, MG, Brazil
| | - James Simpson
- CRAX—Sociedade de Pesquisa do Manejo e da Reprodução da Fauna Silvestre, rua Jarbas Camargo, Chácara Campestre, Contagem, MG, Brazil
| | - Luis F. Silveira
- Seção de Aves, Museu de Zoologia da Universidade de São Paulo, CEP, São Paulo, SP, Brazil
| | - Mercival R. Francisco
- Departamento de Ciências Ambientais, Universidade Federal de São Carlos, Campus de Sorocaba, Rod. João Leme dos Santos, CEP, Sorocaba, SP, Brazil
- * E-mail:
| |
Collapse
|
12
|
Ait Belkacem A, Gast O, Stuckas H, Canal D, LoValvo M, Giacalone G, Päckert M. North African hybrid sparrows (Passer domesticus, P. hispaniolensis) back from oblivion - ecological segregation and asymmetric mitochondrial introgression between parental species. Ecol Evol 2016; 6:5190-206. [PMID: 27551376 PMCID: PMC4984497 DOI: 10.1002/ece3.2274] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/31/2016] [Accepted: 06/03/2016] [Indexed: 01/23/2023] Open
Abstract
A stabilized hybrid form of the house sparrow (Passer domesticus) and the Spanish sparrow (P. hispaniolensis) is known as Passer italiae from the Italian Peninsula and a few Mediterranean islands. The growing attention for the Italian hybrid sparrow and increasing knowledge on its biology and genetic constitution greatly contrast the complete lack of knowledge of the long‐known phenotypical hybrid sparrow populations from North Africa. Our study provides new data on the breeding biology and variation of mitochondrial DNA in three Algerian populations of house sparrows, Spanish sparrows, and phenotypical hybrids. In two field seasons, the two species occupied different breeding habitats: Spanish sparrows were only found in rural areas outside the cities and bred in open‐cup nests built in large jujube bushes. In contrast, house sparrows bred only in the town centers and occupied nesting holes in walls of buildings. Phenotypical hybrids were always associated with house sparrow populations. House sparrows and phenotypical hybrids started breeding mid of March, and most pairs had three successive clutches, whereas Spanish sparrows started breeding almost one month later and had only two successive clutches. Mitochondrial introgression is strongly asymmetric because about 75% of the rural Spanish sparrow population carried house sparrow haplotypes. In contrast, populations of the Italian hybrid form, P. italiae, were genetically least diverse among all study populations and showed a near‐fixation of house sparrow haplotypes that elsewhere were extremely rare or that were even unique for the Italian Peninsula. Such differences between mitochondrial gene pools of Italian and North African hybrid sparrow populations provide first evidence that different demographic histories have shaped the extant genetic diversity observed on both continents.
Collapse
Affiliation(s)
- Abdelkrim Ait Belkacem
- Faculty of Sciences of nature and lifes Department of Agropastoralism University of Djelfa BP. 3117 17000 Djelfa Algeria
| | - Oliver Gast
- Senckenberg Naturhistorische Sammlungen Königsbrücker Landstraße 159D-01109 Dresden Germany; Institute of Vertebrate Biology Czech Academy of Sciences External Research Facility Studenec Studenec 122675 02 Koněšín Czech Republic
| | - Heiko Stuckas
- Senckenberg Naturhistorische Sammlungen Königsbrücker Landstraße 159 D-01109 Dresden Germany
| | - David Canal
- Department of Evolutionary Ecology Estación Biológica de Doñana - CSIC Avda. Américo Vespucio s/n 41092 Seville Spain
| | - Mario LoValvo
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche Via Archirafi 18 I-90123 Palermo Italy
| | | | - Martin Päckert
- Senckenberg Naturhistorische Sammlungen Königsbrücker Landstraße 159 D-01109 Dresden Germany
| |
Collapse
|
13
|
Ottenburghs J, van Hooft P, van Wieren SE, Ydenberg RC, Prins HHT. Hybridization in geese: a review. Front Zool 2016; 13:20. [PMID: 27182276 PMCID: PMC4866292 DOI: 10.1186/s12983-016-0153-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/10/2016] [Indexed: 11/10/2022] Open
Abstract
The high incidence of hybridization in waterfowl (ducks, geese and swans) makes this bird group an excellent study system to answer questions related to the evolution and maintenance of species boundaries. However, knowledge on waterfowl hybridization is biased towards ducks, with a large knowledge gap in geese. In this review, we assemble the available information on hybrid geese by focusing on three main themes: (1) incidence and frequency, (2) behavioural mechanisms leading to hybridization, and (3) hybrid fertility. Hybridization in geese is common on a species-level, but rare on a per-individual level. An overview of the different behavioural mechanisms indicates that forced extra-pair copulations and interspecific nest parasisitm can both lead to hybridization. Other sources of hybrids include hybridization in captivity and vagrant geese, which may both lead to a scarcity of conspecifics. The different mechanisms are not mutually exclusive and it is currently not possible to discriminate between the different mechanisms without quantitative data. Most hybrid geese are fertile; only in crosses between distantly related species do female hybrids become sterile. This fertility pattern, which is in line with Haldane's Rule, may facilitate interspecific gene flow between closely related species. The knowledge on hybrid geese should be used, in combination with the information available on hybridization in ducks, to study the process of avian speciation.
Collapse
Affiliation(s)
- Jente Ottenburghs
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands
| | - Pim van Hooft
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands
| | - Sipke E van Wieren
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands
| | - Ronald C Ydenberg
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands ; Centre of Wildlife Ecology, Simon Fraser University, V5A 1S6 Burnaby, BC Canada
| | - Herbert H T Prins
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands
| |
Collapse
|
14
|
Natarajan C, Projecto-Garcia J, Moriyama H, Weber RE, Muñoz-Fuentes V, Green AJ, Kopuchian C, Tubaro PL, Alza L, Bulgarella M, Smith MM, Wilson RE, Fago A, McCracken KG, Storz JF. Convergent Evolution of Hemoglobin Function in High-Altitude Andean Waterfowl Involves Limited Parallelism at the Molecular Sequence Level. PLoS Genet 2015; 11:e1005681. [PMID: 26637114 PMCID: PMC4670201 DOI: 10.1371/journal.pgen.1005681] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/27/2015] [Indexed: 11/18/2022] Open
Abstract
A fundamental question in evolutionary genetics concerns the extent to which adaptive phenotypic convergence is attributable to convergent or parallel changes at the molecular sequence level. Here we report a comparative analysis of hemoglobin (Hb) function in eight phylogenetically replicated pairs of high- and low-altitude waterfowl taxa to test for convergence in the oxygenation properties of Hb, and to assess the extent to which convergence in biochemical phenotype is attributable to repeated amino acid replacements. Functional experiments on native Hb variants and protein engineering experiments based on site-directed mutagenesis revealed the phenotypic effects of specific amino acid replacements that were responsible for convergent increases in Hb-O2 affinity in multiple high-altitude taxa. In six of the eight taxon pairs, high-altitude taxa evolved derived increases in Hb-O2 affinity that were caused by a combination of unique replacements, parallel replacements (involving identical-by-state variants with independent mutational origins in different lineages), and collateral replacements (involving shared, identical-by-descent variants derived via introgressive hybridization). In genome scans of nucleotide differentiation involving high- and low-altitude populations of three separate species, function-altering amino acid polymorphisms in the globin genes emerged as highly significant outliers, providing independent evidence for adaptive divergence in Hb function. The experimental results demonstrate that convergent changes in protein function can occur through multiple historical paths, and can involve multiple possible mutations. Most cases of convergence in Hb function did not involve parallel substitutions and most parallel substitutions did not affect Hb-O2 affinity, indicating that the repeatability of phenotypic evolution does not require parallelism at the molecular level. The convergent evolution of similar traits in different species could be due to repeated changes at the genetic level or different changes that produce the same phenotypic effect. To investigate the extent to which convergence in phenotype is caused by repeated mutations, we investigated the molecular basis of convergent changes in the oxygenation properties of hemoglobin (Hb) in eight pairs of high- and low-altitude waterfowl taxa from the Andes. The results revealed that convergent increases in Hb-O2 affinity in highland taxa involved a combination of unique and repeated amino acid replacements. However, convergent changes in Hb function generally did not involve parallel substitutions, indicating that repeatability in the evolution of protein function does not require repeatability at the sequence level.
Collapse
Affiliation(s)
- Chandrasekhar Natarajan
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Joana Projecto-Garcia
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Hideaki Moriyama
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Roy E. Weber
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Violeta Muñoz-Fuentes
- Estación Biológica de Doñana-CSIC, Sevilla, Spain
- Conservation Genetics Group, Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, Germany
| | | | - Cecilia Kopuchian
- Centro de Ecología Aplicada del Litoral (CECOAL), Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET), Corrientes, Argentina
| | - Pablo L. Tubaro
- División Ornitología, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ (MACN-CONICET), Buenos Aires, Argentina
| | - Luis Alza
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Mariana Bulgarella
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Matthew M. Smith
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Robert E. Wilson
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Angela Fago
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Kevin G. McCracken
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
- Department of Biology and Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Coral Gables, Florida, United States of America
| | - Jay F. Storz
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
- * E-mail:
| |
Collapse
|
15
|
van de Crommenacker J, Bourgeois YXC, Warren BH, Jackson H, Fleischer-Dogley F, Groombridge J, Bunbury N. Using molecular tools to guide management of invasive alien species: assessing the genetic impact of a recently introduced island bird population. DIVERS DISTRIB 2015. [DOI: 10.1111/ddi.12364] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- J. van de Crommenacker
- Seychelles Islands Foundation; La Ciotat Building, Mont Fleuri, Mahé Victoria Seychelles
- Durrell Institute of Conservation and Ecology (DICE); School of Anthropology and Conservation; University of Kent; Marlowe Building Canterbury Kent UK
| | - Y. X. C. Bourgeois
- Zoologisches Institut, Evolutionsbiologie; University of Basel; Vesalgasse 1 4051 Basel Switzerland
| | - B. H. Warren
- Institute of Systematic Botany; University of Zurich; Zollikerstrasse 107 8008 Zurich Switzerland
| | - H. Jackson
- Durrell Institute of Conservation and Ecology (DICE); School of Anthropology and Conservation; University of Kent; Marlowe Building Canterbury Kent UK
| | - F. Fleischer-Dogley
- Seychelles Islands Foundation; La Ciotat Building, Mont Fleuri, Mahé Victoria Seychelles
| | - J. Groombridge
- Durrell Institute of Conservation and Ecology (DICE); School of Anthropology and Conservation; University of Kent; Marlowe Building Canterbury Kent UK
| | - N. Bunbury
- Seychelles Islands Foundation; La Ciotat Building, Mont Fleuri, Mahé Victoria Seychelles
| |
Collapse
|
16
|
Coleman RR, Gaither MR, Kimokeo B, Stanton FG, Bowen BW, Toonen RJ. Large-scale introduction of the Indo-Pacific damselfishAbudefduf vaigiensisinto Hawai'i promotes genetic swamping of the endemic congenerA. abdominalis. Mol Ecol 2014; 23:5552-65. [DOI: 10.1111/mec.12952] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Richard R. Coleman
- Hawai'i Institute of Marine Biology; University of Hawai'i; P.O. Box 1346 Kaneohe HI 96744 USA
- Department of Biology; University of Hawai'i; Mānoa, 2450 Campus Road, Dean Hall Room 2 Honolulu HI 96822 USA
| | - Michelle R. Gaither
- Section of Ichthyology; California Academy of Sciences; 55 Music Concourse Drive San Francisco CA 94118 USA
- School of Biological and Biomedical Sciences; Durham University; South Road Durham DH1 3LE UK
| | - Bethany Kimokeo
- Hawai'i Institute of Marine Biology; University of Hawai'i; P.O. Box 1346 Kaneohe HI 96744 USA
| | - Frank G. Stanton
- University of Hawai'i Community Colleges; Leeward Community College; 96-045 Ala Ike Pearl City HI 96782 USA
| | - Brian W. Bowen
- Hawai'i Institute of Marine Biology; University of Hawai'i; P.O. Box 1346 Kaneohe HI 96744 USA
| | - Robert J. Toonen
- Hawai'i Institute of Marine Biology; University of Hawai'i; P.O. Box 1346 Kaneohe HI 96744 USA
| |
Collapse
|
17
|
McCracken KG, Wilson RE, Martin AR. Gene flow and hybridization between numerically imbalanced populations of two duck species on the subantarctic island of South Georgia. PLoS One 2013; 8:e82664. [PMID: 24367536 PMCID: PMC3867383 DOI: 10.1371/journal.pone.0082664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 10/26/2013] [Indexed: 11/30/2022] Open
Abstract
Hybridization is common between species of animals, particularly in waterfowl (Anatidae). One factor shown to promote hybridization is restricted mate choice, which can occur when 2 species occur in sympatry but one is rare. According to the Hubbs principle, or "desperation hypothesis," the rarer species is more likely to mate with heterospecifics. We report the second of 2 independent examples of hybridization between 2 species of ducks inhabiting island ecosystems in the Subantarctic and South Atlantic Ocean. Yellow-billed pintails (Anas georgica) and speckled teal (Anas flavirostris) are abundant in continental South America, where they are sympatric and coexist in mixed flocks. But on South Georgia, an isolated island in the Subantarctic, the pintail population of approximately 6000 pairs outnumbers a small breeding population of speckled teal 300∶1. Using 6 genetic loci (mtDNA and 5 nuclear introns) and Bayesian assignment tests coupled with coalescent analyses, we identified hybrid-origin speckled teal alleles in 2 pintails on South Georgia. While it is unclear whether introgression has also occurred into the speckled teal population, our data suggest that this hybridization was not a recent event, but occurred some time ago. We also failed to identify unequivocal evidence of introgression in a much larger sample of pintails and speckled teal from Argentina using a 3-population "Isolation-with-Migration" coalescent analysis. Combined with parallel findings of hybridization between these same 2 duck species in the Falkland Islands, where population ratios are reversed and pintails are outnumbered by speckled teal 1:10, our results provide further support for the desperation hypothesis, which predicts that scarcity in one population and abundance of another will often lead to hybridization. While the South Georgia pintail population appears to be thriving, it's possible that low density of conspecific mates and inverse density dependence (Allee effect) may be one factor limiting the reproductive output of the speckled teal population, and this situation may persist unless speckled teal increase in abundance on South Georgia.
Collapse
Affiliation(s)
- Kevin G. McCracken
- Institute of Arctic Biology, University of Alaska Museum, and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
- * E-mail:
| | - Robert E. Wilson
- Institute of Arctic Biology, University of Alaska Museum, and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Anthony R. Martin
- Centre for Remote Environments, University of Dundee, Dundee, United Kingdom
| |
Collapse
|
18
|
CAMPAGNA LEONARDO, ST CLAIR JAMESJH, LOUGHEED STEPHENC, WOODS ROBINW, IMBERTI SANTIAGO, TUBARO PABLOL. Divergence between passerine populations from the Malvinas - Falkland Islands and their continental counterparts: a comparative phylogeographical study. Biol J Linn Soc Lond 2012. [DOI: 10.1111/j.1095-8312.2012.01898.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
19
|
Peters JL, Bolender KA, Pearce JM. Behavioural vs. molecular sources of conflict between nuclear and mitochondrial DNA: the role of male-biased dispersal in a Holarctic sea duck. Mol Ecol 2012; 21:3562-75. [PMID: 22582867 DOI: 10.1111/j.1365-294x.2012.05612.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Jeffrey L Peters
- Department of Biological Sciences, 3640 Colonel Glenn Hwy, Wright State University, Dayton, OH, USA.
| | | | | |
Collapse
|
20
|
Peters JL, Roberts TE, Winker K, McCracken KG. Heterogeneity in genetic diversity among non-coding loci fails to fit neutral coalescent models of population history. PLoS One 2012; 7:e31972. [PMID: 22384117 PMCID: PMC3285185 DOI: 10.1371/journal.pone.0031972] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 01/17/2012] [Indexed: 12/26/2022] Open
Abstract
Inferring aspects of the population histories of species using coalescent analyses of non-coding nuclear DNA has grown in popularity. These inferences, such as divergence, gene flow, and changes in population size, assume that genetic data reflect simple population histories and neutral evolutionary processes. However, violating model assumptions can result in a poor fit between empirical data and the models. We sampled 22 nuclear intron sequences from at least 19 different chromosomes (a genomic transect) to test for deviations from selective neutrality in the gadwall (Anas strepera), a Holarctic duck. Nucleotide diversity among these loci varied by nearly two orders of magnitude (from 0.0004 to 0.029), and this heterogeneity could not be explained by differences in substitution rates alone. Using two different coalescent methods to infer models of population history and then simulating neutral genetic diversity under these models, we found that the observed among-locus heterogeneity in nucleotide diversity was significantly higher than expected for these simple models. Defining more complex models of population history demonstrated that a pre-divergence bottleneck was also unlikely to explain this heterogeneity. However, both selection and interspecific hybridization could account for the heterogeneity observed among loci. Regardless of the cause of the deviation, our results illustrate that violating key assumptions of coalescent models can mislead inferences of population history.
Collapse
Affiliation(s)
- Jeffrey L Peters
- Department of Biological Sciences, Wright State University, Dayton, Ohio, United States of America.
| | | | | | | |
Collapse
|