Morphological Differences in Pacific Coast Populations of Greater White-Fronted Geese

Orthmeyer, D.L.; Takekawa, John Y.; Ely, Craig R.; Wege, Michael L.; Newton, Wesley E.

doi:10.2307/1368990

Cited by 15 publications

(11 citation statements)

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“…However, the amount of mtDNA genetic variation explained when eastern Palearctic are grouped by themselves (flyway AMOVA grouping) explained approximately the same amount of mtDNA genetic variation (11% vs. 13%) as that under the subspecies model (subspecies AMOVA grouping, see Table ). In addition, we found no genetic support for the proposed subspecies ( A. a. sponsa ; Banks, ; but see Orthmeyer et al., ), based on their smaller average body size, encompassing the Yukon‐Kuskokwim Delta and Bristol Bay regions. Due to the lack of clear distinction in subspecies attributions, based on mtDNA sequence data and the presence of multiple body sizes along with a clear phenotypic body size cline in Eurasia, a genomic approach may be needed to determine if the different phenotypes represent genetically discrete populations, and to test taxonomic designations used to make management prescriptions.…”

Section: Discussioncontrasting

confidence: 60%

Flyway structure in the circumpolar greater white‐fronted goose

Wilson

Ely

Talbot

2018

Ecology and Evolution

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Dispersal and migratory behavior are influential factors in determining how genetic diversity is distributed across the landscape. In migratory species, genetic structure can be promoted via several mechanisms including fidelity to distinct migratory routes. Particularly within North America, waterfowl management units have been delineated according to distinct longitudinal migratory flyways supported by banding data and other direct evidence. The greater white‐fronted goose (Anser albifrons) is a migratory waterfowl species with a largely circumpolar distribution consisting of up to six subspecies roughly corresponding to phenotypic variation. We examined the rangewide population genetic structure of greater white‐fronted geese using mtDNA control region sequence data and microsatellite loci from 23 locales across North America and Eurasia. We found significant differentiation in mtDNA between sampling locales with flyway delineation explaining a significant portion of the observed genetic variation (~12%). This is concordant with band recovery data which shows little interflyway or intercontinental movements. However, microsatellite loci revealed little genetic structure suggesting a panmictic population across most of the Arctic. As with many high‐latitude species, Beringia appears to have played a role in the diversification of this species. A common Beringian origin of North America and Asian populations and a recent divergence could at least partly explain the general lack of structure at nuclear markers. Further, our results do not provide strong support for the various taxonomic proposals for this species except for supporting the distinctness of two isolated breeding populations within Cook Inlet, Alaska (A. a. elgasi) and Greenland (A. a. flavirostris), consistent with their subspecies status.

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Section: Discussioncontrasting

confidence: 60%

Flyway structure in the circumpolar greater white‐fronted goose

Wilson

Ely

Talbot

2018

Ecology and Evolution

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“…In addition, bacular variation was assessed using a MANOVA, a five-group linear discriminant function analysis, a principle components analysis (PCA; a priori taxonomic groups were not assumed for this analysis), and a canonical variate analysis (CVA). Classification ability of linear functions was assessed using a jackknife procedure (Lance et al 2000) and a randomized cross-validation procedure (Orthmeyer et al 1995), with approximately 0.65 of the group used to estimate a linear function with which the residual test sample was identified. All individuals, including ungrouped juveniles and specimens of unknown age, were classified based on their generalized statistical distance (Mahalanobis' D 2 ;Mahalanobis 1936) and the corresponding posterior probability of group membership (Reyment et al 1984).…”

Section: Morphometric Data Collection and Analysesmentioning

confidence: 99%

Phylogeography and Introgressive Hybridization: Chipmunks (Genus Tamias) in the Northern Rocky Mountains

et al. 2003

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Abstract. If phylogeographic studies are to be broadly used for assessing population-level processes relevant to speciation and systematics, the ability to identify and incorporate instances of hybridization into the analytical framework is essential. Here, we examine the evolutionary history of two chipmunk species, Tamias ruficaudus and Tamias amoenus, in the northern Rocky Mountains by integrating multivariate morphometrics of bacular (os penis) variation, phylogenetic estimation, and nested clade analysis with regional biogeography. Our results indicate multiple examples of mitochondrial DNA introgression layered within the evolutionary history of these nonsister species. Three of these events are most consistent with recent and/or ongoing asymmetric introgression of mitochondrial DNA across morphologically defined secondary contact zones. In addition, we find preliminary evidence where a fourth instance of nonconcordant characters may represent complete fixation of introgressed mitochondrial DNA via a more ancient hybridization event, although alternative explanations of convergence or incomplete sorting of ancestral polymorphisms cannot be dismissed with these data. The demonstration of hybridization among chipmunks with strongly differentiated bacular morphology contradicts long-standing assumptions that variation within this character is diagnostic of complete reproductive isolation within Tamias. Our results illustrate the utility of phylogeographic analyses for detecting instances of reticulate evolution and for incorporating this and other information in the inference of the evolutionary history of species.

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“…In the Pacific Flyway, white‐fronted geese nest in three areas of Alaska: the Yukon–Kuskokwim Delta (YKD) of western Alaska, the Bristol Bay Lowlands (BBL) in southwestern Alaska, and the Cook Inlet Basin (CIB) of south central Alaska (Figure a). Previous investigations of white‐fronted geese in the Pacific Flyway revealed differences among geese sampled from these three breeding locales with respect to morphology (Ely et al., ; Orthmeyer, Takekawa, Ely, Wege, & Newton, ), distribution (Ely & Takekawa, ), and timing of migration and reproduction (Ely, ; Ely & Takekawa, ), such that the three locales are considered to comprise discrete nesting populations. The populations are allopatric during the summer nesting season, but overlap in distribution during the nonbreeding season (Ely & Takekawa, ; Ely, ; Figure a).…”

Section: Introductionmentioning

confidence: 99%

“…Although greater white‐fronted geese from the three locales sampled in our study occupy a single migratory flyway, we nevertheless anticipated some degree of population genetic differentiation given that mtDNA is maternally inherited and most species of waterfowl exhibit female natal philopatry (Greenwood, ). Evidence of population genetic structuring also seemed likely as the three populations vary in body size (Ely et al., ; Orthmeyer et al., ), with the distinctly larger structural size of Tule geese (CIB population) likely contributing to resource partitioning (CIB geese are adapted to feed on aquatic marsh plants; Ely, ), and reproductive isolation through sexual imprinting mechanisms. We also expected gene flow among the populations to be lowest between CIB and the other populations, given the likelihood that the populations are allopatric during the time of mate selection.…”

Section: Introductionmentioning

confidence: 99%

Genetic structure among greater white‐fronted goose populations of the Pacific Flyway

Ely

Wilson

Talbot

2017

Ecology and Evolution

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An understanding of the genetic structure of populations in the wild is essential for long‐term conservation and stewardship in the face of environmental change. Knowledge of the present‐day distribution of genetic lineages (phylogeography) of a species is especially important for organisms that are exploited or utilize habitats that may be jeopardized by human intervention, including climate change. Here, we describe mitochondrial (mtDNA) and nuclear genetic (microsatellite) diversity among three populations of a migratory bird, the greater white‐fronted goose (Anser albifrons), which breeds discontinuously in western and southwestern Alaska and winters in the Pacific Flyway of North America. Significant genetic structure was evident at both marker types. All three populations were differentiated for mtDNA, whereas microsatellite analysis only differentiated geese from the Cook Inlet Basin. In sexual reproducing species, nonrandom mate selection, when occurring in concert with fine‐scale resource partitioning, can lead to phenotypic and genetic divergence as we observed in our study. If mate selection does not occur at the time of reproduction, which is not uncommon in long‐lived organisms, then mechanisms influencing the true availability of potential mates may be obscured, and the degree of genetic and phenotypic diversity may appear incongruous with presumed patterns of gene flow. Previous investigations revealed population‐specific behavioral, temporal, and spatial mechanisms that likely influence the amount of gene flow measured among greater white‐fronted goose populations. The degree of observed genetic structuring aligns well with our current understanding of population differences pertaining to seasonal movements, social structure, pairing behavior, and resource partitioning.

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Morphological Differences in Pacific Coast Populations of Greater White-Fronted Geese

Cited by 15 publications

References 10 publications

Flyway structure in the circumpolar greater white‐fronted goose

Flyway structure in the circumpolar greater white‐fronted goose

Phylogeography and Introgressive Hybridization: Chipmunks (Genus Tamias) in the Northern Rocky Mountains

Genetic structure among greater white‐fronted goose populations of the Pacific Flyway

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