Burg, Theresa

Permanent URI for this collection

https://opus.uleth.ca/handle/10133/4449

Browse

Browsing Burg, Theresa by Author "Dohms, Kimberly M."

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Cryptic genetic diversity and cytonuclear discordance characterize contact among Canada Jay (Perisoreus canadensis) morphotypes in western North America
    (Oxford Academic, 2021) Graham, Brendan A.; Cicero, Carla; Strickland, Dan; Woods, John G.; Coneybeare, Howard; Dohms, Kimberly M.; Szabo, Ildiko; Burg, Theresa M.
    Three distinct Canada jay (Perisoreus canadensis) morphotypes with easily recognizable plumage traits come into contact in western North America. Recent work demonstrated high genetic structure across the species’ range; however, patterns of genetic variation in these contact zones remain unknown. We categorized 605 individuals into one of three morphotypes (Pacific, Rocky Mountain, and Boreal) based on plumage, and genotyped individuals at the mtDNA control region and 12 microsatellite loci to assess the extent of hybridization between morphotypes. Our data showed cryptic genetic diversity and high cytonuclear discordance among morphotypes within contact zones, which is likely the result of recent and historical admixture. The distributions of the Boreal and Pacific morphotypes each showed a strong association with a single, distinct genetic group, whereas the Rocky Mountain morphotype exhibited higher genetic diversity and was associated with multiple genotypes. Our analyses show the importance of considering both plumage and genetic traits when examining contact zones between closely related taxa. Finally the data presented in this study reaffirm that the Pacific morphotype is distinct from the Boreal and Rocky Mountain morphotypes based on genetic, phenotypic and ecological data, indicating that the Pacific morphotype should be re-elevated to a full species.
  • Thumbnail Image
    Item
    Limited geographic genetic structure detected in a widespread Palearctic corvid, Nucifraga caryocatactes
    (Peer J, Ltd, 2014) Dohms, Kimberly M.; Burg, Theresa M.
    The Eurasian or spotted nutcracker (Nucifraga caryocatactes) is a widespread resident corvid found throughout the Palearctic fromCentral Europe to Japan. Characterized by periodic bouts of irruptive dispersal in search of Pinus seed crops, this species has potential for high levels of gene flow across its range. Previous analysis of 11 individuals did not find significant range-wide population genetic structure.We investigated population structure using 924 base pairs of mitochondrial DNA control region sequence data from 62 individuals from 12 populations distributed throughout the nutcracker’s range.We complemented this analysis by incorporating additional genetic data frompreviously published sequences.High levels of genetic diversity and limited population genetic structure were detected suggesting that potential barriers to dispersal do not restrict gene flow in nutcrackers.
  • Thumbnail Image
    Item
    Molecular markers reveal limited population genetic structure in a North American corvid, Clark's nutcracker (Nucifraga columbiana)
    (Public Library of Science, 2013) Dohms, Kimberly M.; Burg, Theresa M.
    The genetic impact of barriers and Pleistocene glaciations on high latitude resident species has not been widely investigated. The Clark’s nutcracker is an endemic North American corvid closely associated with Pinus-dominated forests. The nutcracker’s encompasses known barriers to dispersal for other species, and glaciated and unglaciated areas. Clark’s nutcrackers also irruptively disperse long distances in search of pine seed crops, creating the potential for gene flow among populations. Using the highly variable mitochondrial DNA control region, seven microsatellite loci, and species distribution modeling, we examined the effects of glaciations and dispersal barriers on population genetic patterns and population structure of nutcrackers. We sequenced 900 bp of mitochondrial control region for 169 individuals from 15 populations and analysed seven polymorphic microsatellite loci for 13 populations across the Clark’s nutcracker range. We used species distribution modeling and a range of phylogeographic analyses to examine evolutionary history. Clark’s nutcracker populations are not highly differentiated throughout their range, suggesting high levels of gene flow among populations, though we did find some evidence of isolation by distance and peripheral isolation. Our analyses suggested expansion from a single refugium after the last glacial maximum, but patterns of genetic diversity and paleodistribution modeling of suitable habitat were inconclusive as to the location of this refugium. Potential barriers to dispersal (e.g. mountain ranges) do not appear to restrict gene flow in Clark’s nutcracker, and postglacial expansion likely occurred quickly from a single refugium located south of the ice sheets.
  • Thumbnail Image
    Item
    Multilocus genetic analysis and spatial modeling reveal complex population structure and history in a widespread resident North America passerine (Perisoreus canadensis)
    (Wiley, 2017) Dohms, Kimberly M.; Graham, Brendan A.; Burg, Theresa M.
    An increasing body of studies of widely distributed, high latitude species shows a variety of refugial locations and population genetic patterns. We examined the effects of glaciations and dispersal barriers on the population genetic patterns of a widely distributed, high latitude, resident corvid, the gray jay (Perisoreus canadensis), using the highly variable mitochondrial DNA (mtDNA) control region and microsatellite markers combined with species distribution modeling. We sequenced 914 bp of mtDNA control region for 375 individuals from 37 populations and screened seven loci for 402 individuals from 27 populations across the gray jay range. We used species distribution modeling and a range of phylogeographic analyses (haplotype diversity, ΦST, SAMOVA, FST, Bayesian clustering analyses) to examine evolutionary history and population genetic structure. MtDNA and microsatellite markers revealed significant genetic differentiation among populations with high concordance between markers. Paleodistribution models supported at least five potential areas of suitable gray jay habitat during the last glacial maximum and revealed distributions similar to the gray jay’s contemporary during the last interglacial. Colonization from and prolonged isolation in multiple refugia is evident. Historical climatic fluctuations, the presence of multiple dispersal barriers, and highly restricted gene flow appear to be responsible for strong genetic diversification and differentiation in gray jays.