Jeffrey L. Peters

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Many species have mitochondrial DNA lineages that are phylogenetically intermixed with other species, but studies have rarely tested the cause of such paraphyly. In this study, we tested two hypotheses that could explain mitochondrial paraphyly of Holarctic gadwalls (Anas strepera) with respect to Asian falcated ducks (A. falcata). First, hybridization(More)
During the Late Pleistocene, glaciers sundered many species into multiple glacial refugia where populations diverged in allopatry. Although deeply divergent mitochondrial DNA (mtDNA) lineages often reflect the number of refugia occupied, it is unlikely that populations that split during the recent Wisconsin glaciations will have reached reciprocal(More)
When populations become locally adapted to contrasting environments, alleles that have high fitness in only one environment may be quickly eliminated in populations adapted to other environments, such that gene flow is partly restricted. The stronger the selection, the more rapidly immigrant alleles of lower fitness will be eliminated from the population.(More)
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(More)
Spatial variation in the environment can lead to divergent selection between populations occupying different parts of a species' range, and ultimately lead to population divergence. The colonization of new areas can thus facilitate divergence in beneficial traits, yet with little differentiation at neutral genetic markers. We investigated genetic and(More)
Species-level DNA phylogenies frequently suffer from two shortcomings--gene trees usually are constructed from a single locus, and often species are represented by only one individual. To evaluate the effect of these two shortcomings, we tested phylogenetic hypotheses within the wigeons and allies, a clade of Anas ducks (Anatidae) composed of five species.(More)
More than 100 species of birds have Holarctic distributions extending across Eurasia and North America, and many of them likely achieved these distributions by recently colonizing one continent from the other. Mitochondrial DNA (mtDNA) and five nuclear introns were sequenced to test the direction and timing of colonization for a Holarctic duck, the gadwall(More)
Hypoxia is one of the most important factors affecting survival at high altitude, and the major hemoglobin protein is a likely target of selection. We compared population genetic structure in the alphaA and betaA hemoglobin subunits (HBA2 and HBB) of five paired lowland and highland populations of Andean dabbling ducks to unlinked reference loci. In the(More)
Hypoxia is a key factor determining survival, and haemoglobins are targets of selection in species native to high-altitude regions. We studied population genetic structure and evaluated evidence for local adaptation in the crested duck (Lophonetta specularioides). Differentiation, gene flow and time since divergence between highland and lowland populations(More)
The relevance of spatial variation in the environment and host communities for parasite community composition is poorly documented, creating a need for additional case studies from which general principles can be developed. Avian malaria in southern African waterfowl has not previously been studied. As a first step towards documenting and understanding its(More)