Morphological and genetic concordance of cutthroat trout diversification from western North America

2021 ◽  
Author(s):  
Ernest R Keeley ◽  
Janet L Loxterman ◽  
Sammy L Matsaw ◽  
Zacharia M Njoroge ◽  
Meredith B Seiler ◽  
...  
Keyword(s):  
North America ◽  
Phenotypic Variability ◽  
Sequence Divergence ◽  
Cutthroat Trout ◽  
Distance Measures ◽  
Western North America ◽  
Morphological Comparison ◽  
Oncorhynchus Clarkii ◽  
Diverse Range ◽  
Mtdna Sequence

The cutthroat trout, Oncorhynchus clarkii (Richardson, 1836), is one of the most widely distributed species of freshwater fish in western North America. Occupying a diverse range of habitats, they exhibit significant phenotypic variability that is often recognized by intraspecific taxonomy. Recent molecular phylogenies have described phylogenetic diversification across cutthroat trout populations, but no study has provided a range-wide morphological comparison of taxonomic divisions. In this study, we used linear and geometric-based morphometrics to determine if phylogenetic and subspecies divisions correspond to morphological variation in cutthroat trout, using replicate populations from throughout the geographic range of the species. Our data indicate significant morphological divergence of intraspecific categories in some, but not all, cutthroat trout subspecies. We also compare morphological distance measures with distance measures of mtDNA sequence divergence. DNA sequence divergence was positively correlated with morphological distance measures, indicating that morphologically more similar subspecies have lower sequence divergence in comparison to morphologically distant subspecies. Given these results, integrating both approaches to describing intraspecific variation may be necessary for developing a comprehensive conservation plan in wide-ranging species.

Mitochondrial DNA variation in water shrews (Sorex palustris, Sorex bendirii) from western North America: implications for taxonomy and phylogeography

2005 ◽  
Vol 83 (11) ◽  
pp. 1469-1475 ◽  
Author(s):  
M B O'Neill ◽  
D W Nagorsen ◽  
R J Baker
Keyword(s):  
Mitochondrial Dna ◽  
North America ◽  
Phylogenetic Analyses ◽  
Sequence Divergence ◽  
Vancouver Island ◽  
Western North America ◽  
Cytb Sequence ◽  
Dna Variation ◽  
Late Pliocene ◽  
Postglacial Colonization

Inter- and intra-specific variations in cytochrome b (Cytb) sequence were assessed in 22 specimens of Sorex palustris Richardson, 1828 and 6 specimens of Sorex bendirii (Merriam, 1884) from 20 locations in western North America. Phylogenetic analyses revealed three distinct clades: Boreal (S. p. palustris), Cordilleran (S. p. brooksi, S. p. navigator), and Coastal (S. b. palmeri, S. b. bendirii). Sequence divergence between the Boreal and the Coastal–Cordilleran lineages was 6.9%, while the divergence between the Coastal and the Cordilleran clades was 3.1%. Sorex palustris brooksi, a subspecies endemic to Vancouver Island, showed minor divergence from mainland samples of S. p. navigator. The results suggest that S. palustris may consist of two species: a boreal eastern form (S. palustris) and a Cordilleran form (S. navigator). The taxonomic validity of S. p. brooksi is unresolved. Distribution of the three clades are consistent with vicariance and isolation in coastal, Cordilleran, and eastern refugia in the Late Pliocene or Pleistocene. The Vancouver Island subspecies S. p. brooksi is probably derived from postglacial colonization in the Late Pleistocene.

Mitochondrial and nuclear genetic relationships of deer (Odocoileus spp.) in western North America

1991 ◽  
Vol 69 (5) ◽  
pp. 1270-1279 ◽  
Author(s):  
Matthew A. Cronin
Keyword(s):  
Gene Flow ◽  
North America ◽  
Genetic Relationships ◽  
Mitochondrial Gene ◽  
Mule Deer ◽  
Introgressive Hybridization ◽  
Nuclear Gene ◽  
Allele Frequencies ◽  
Western North America ◽  
Mtdna Sequence

Odocoileus hemionus (mule deer and black-tailed deer) and Odocoileus virginanus (white-tailed deer) are sympatric in western North America and are characterized by distinct morphology, behavior, and allozyme allele frequencies. However, there is discordance among nuclear and mitochondrial genetic relationships, as mule deer (O. h. hemionus) and white-tailed deer have similar mitochondrial DNA (mtDNA) which is very different from that of black-tailed deer (O. h. columbianus, O. h. sitkensis). I expanded previous studies to clarify the genetic relationships of these groups by determining mtDNA haplotype and allozyme genotypes for 667 deer from several locations in northwestern North America. Different mtDNA haplotypes in mule deer, black-tailed deer, and white-tailed deer indicate that mitochondrial gene flow is restricted. Allozyme allele frequencies indicate that there is also restriction of nuclear gene flow between O. virginianus and O. hemionus, and to a lesser extent between mule deer and black-tailed deer. There is a low level of introgressive hybridization of mtDNA from mule deer and black-tailed deer into white-tailed deer populations and considerable interbreeding of mule deer and black-tailed deer in a contact zone. The discordance of mitochondrial and nuclear genomes is apparent only if mtDNA sequence divergences, and not haplotype frequencies, are considered.

scholarly journals Phylogeography of Canada Geese (Branta Canadensis) in Western North America

The Auk ◽  
2003 ◽  
Vol 120 (3) ◽  
pp. 889-907
Author(s):  
Kim T. Scribner ◽  
Sandra L. Talbot ◽  
John M. Pearce ◽  
Barbara J. Pierson ◽  
Karen S. Bollinger ◽  
...  
Keyword(s):  
North America ◽  
Sequence Data ◽  
Incomplete Lineage Sorting ◽  
Molecular Genetic ◽  
Sequence Divergence ◽  
Branta Canadensis ◽  
Canada Geese ◽  
Western North America ◽  
Gene Trees ◽  
Lineage Sorting

Abstract Using molecular genetic markers that differ in mode of inheritance and rate of evolution, we examined levels and partitioning of genetic variation for seven nominal subspecies (11 breeding populations) of Canada Geese (Branta canadensis) in western North America. Gene trees constructed from mtDNA control region sequence data show that subspecies of Canada Geese do not have distinct mtDNA. Large and small-bodied forms of Canada Geese were highly diverged (0.077 average sequence divergence) and represent monophyletic groups. A majority (65%) of 20 haplotypes resolved were observed in single breeding locales. However, within both large and small-bodied forms certain haplotypes occurred across multiple subspecies. Population trees for both nuclear (microsatellites) and mitochondrial markers were generally concordant and provide resolution of population and subspecific relationships indicating incomplete lineage sorting. All populations and subspecies were genetically diverged, but to varying degrees. Analyses of molecular variance, nested-clade and coalescencebased analyses of mtDNA suggest that both historical (past fragmentation) and contemporary forces have been important in shaping current spatial genetic distributions. Gene flow appears to be ongoing though at different rates, even among currently recognized subspecies. The efficacy of current subspecific taxonomy is discussed in light of hypothesized historical vicariance and current demographic trends of management and conservation concern.

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