Search

In the absence of obvious barriers to dispersal microsatellite studies of vagile mammalian carnivores frequently find panmictic-like genetic structure over wide scales, whereas high levels of differentiation at much finer scales are detected with mitochondrial DNA (mtDNA). Given the maternal inheritance of mtDNA, these differences are often attributed to male-biased dispersal, remnants of postglacial range expansion, or both. Based on such contrasting results, it is not always clear how to delineate contemporary populations. We investigated the genetic structure of American black bears (Ursus americanus) over a wide geographic area (>1,700 km) that has no obvious physiogeographic barriers to gene flow. We analyzed a 315-base pair fragment of the mtDNA control region from 660 individual bears from 23 regions of Ontario, Canada. Relative to black bear studies based on nuclear data, mitochondrial analyses revealed much stronger patterns of genetic structure among regions (0.09 < FST < 0.44), even at small-scale intervals (<150 km), which likely reflects strong female philopatry combined with male-biased dispersal. The patterns of genetic differentiation among regions were consistent with previously described historical patterns in black bears, specifically the division of the species into 2 phylogeographic clades (coastal and continental). We confirmed that further subdivision of the continental clade occurs in a region where obvious physiogeographic barriers do not exist. We postulate that this small-scale differentiation can be explained by residual patterns from postglacial recolonization routes on either side of the Great Lakes. We suggest that it was maintained through extreme female philopatry due to habitat saturation following the postglacial geographic expansion. Based on our results, we propose that a combination of several molecular markers can be more useful in defining population units for conservation and management decisions than biparentally inherited microsatellites. [ABSTRACT FROM AUTHOR]

Deals with a study which developed a polymerase chain reaction-based method for gender determination in a wide variety of marine and terrestrial mammals. Materials and methods; Results; Discussion.

Many long-term studies of wildlife populations rely on individual identification based on natural markings or genetic profiling, or both. However, only rarely are these 2 independent data sets systematically compared with each other to estimate the error rates inherent in these studies. Here, >25 years of photo-identification data on the endangered North Atlantic right whale (Eubalaena glacialis) were compared with high-resolution genetic profiles, available for >75% of the individuals in the photo-identification catalog, in order to identify sources and rates of errors associated with both methods of individual identification. The resulting estimates were 0.0308 errors/identification for the photo-identification data, and 0.00121 errors/locus and 0.0327 errors/multilocus profile for the genetic data. These are among the lowest error rates yet reported, and indicate that the approaches used provide reliable means of individual identification for this species. However, despite these low error rates, the large size of the data sets results in a nonnegligible estimated number of errors, indicating that the potential for these errors needs to be incorporated into other analyses that are based on these data. A similar situation likely exists in other long-term studies where, although error rates are assumed to be low, the size of the data set results in a large number of errors that will influence subsequent analyses. Regularly conducting and reporting extensive database comparisons such as this is invaluable for maintaining the integrity of long-term data sets by identifying where sources of error are occurring and how protocols can be improved to lower error rates in the future. [ABSTRACT FROM AUTHOR]

Recent genetic data indicate that the eastern wolf is not a subspecies of the gray wolf (Canis lupus), but is a North American wolf more similar to the red wolf (C. rufus) and closely related to the coyote (C. latrans). The eastern wolf has been proposed as a separate species, C. lycaon. The largest protected area containing this wolf is Algonquin Provincial Park in Ontario, Canada, which is bounded to the south by areas containing the Tweed wolf or eastern coyote, a hybrid of the western coyote and eastern wolf. We assessed the relationships of animals in the park by using DNA profiles that comprised the genotype from 17 autosomal and 4 Y-linked microsatellite loci and the mitochondrial DNA control region. These profiles were used to establish maternity, paternity, and kin relationships for 102 wolves that were studied from 24 packs over a 12-year period. Genetic data do not support the hypothesis that a pack comprises an unrelated breeding pair and their offspring. There is evidence of frequent pack splitting, pack fusion, and adoption. Some unrelated individuals in the packs were identified as immigrants into the park. We found high levels of genetic structuring between the Tweed wolves to the southeast and the Algonquin Park wolves (RST = 0.114). Lower levels of genetic differentiation with animals to the north and west (RST = 0.057 and RST = 0.036) and high genetic diversity suggest that park animals are not an island population but the southern part of a larger metapopulation of C. lycaon. [ABSTRACT FROM AUTHOR]