Major Histocompatibility Complex Variation in Red Wolves: Evidence for Common Ancestry with Coyotes and Balancing Selection
Hedrick, P.W.; Lee, R.N.; Garrigan, D., Molecular Ecology, 11/10 (October 2002) 1905 (9pp)
We examined variation at a class II major histocompatibility complex (MHC) gene (DRB1) in the captive red wolf population and samples of coyotes from Texas and North Carolina. We found 4 alleles in the 48 red wolves, 8 alleles in the 10 coyotes from Texas and 15 alleles in the 29 coyotes from North Carolina. Two of the four alleles found in red wolves, Caru-2 and Caru-4, were found in both the Texas and North Carolina coyote samples. Allele Caru1, previously found in gray wolves, was also found in the North Carolina sample. The most frequent red wolf allele, Caru-3, was not found in any of the coyote samples. However, an allele found in both the Texas and North Carolina coyote samples is only one nucleotide (one amino acid) different from this red wolf allele. Overall, it appears from examination of this MHC gene that red wolves are more closely related to coyotes than to gray wolves. There were a number of different types of evidence supporting the action of balancing selection in red wolves. Namely, there was: (i) an excess of heterozygotes compared with expectations; (ii) a higher rate of nonsynonymous than synonymous substitution for the functionally important antigen-binding site positions; (iii) an eight times higher average heterozygosity of individual amino acids at the positions identified as part of the antigenbinding site than those not associated with it; (iv) the amino acid divergence of four red wolf alleles was greater than that expected from a simulation of genetic drift; and (v) the distribution of alleles, and the distributions of amino acids at many positions were more even than expected from neutrality. Examination of the level and pattern of linkage disequilibria between pairs of sites suggest that the heterozygosity, substitution and frequencies at individual amino acids are not highly dependent upon each other.
Mirrors and Metaphors: Contemporary Narratives of the Wolf in Minnesota
Byrd, K., Ethics, Place & Environment, 5/1 (March 2002), 50 (16pp)
This article serves as a case study of how contemporary residents of the Upper Great Lakes states debate the ethics and meanings of living with wolves. An overview of the challenges facing Minnesota wolf management is provided, and the results of a Q-methodology study are presented. The study revealed three primary factors, or shared belief systems, about wolf management in Minnesota. The idealist perspective tells a redemption story of sin and atonement, the institutional perspective endorses scientific management and rationality and the localist perspective promises justice, respect and acknowledgement for its champions. The factors are interpreted as narratives or latent myths that provide a set of tacit directions to its adherents about understanding the complexities of living among carnivores. The intricacies and unique logic of each of the three factors are discussed, and themes of consensus and disagreement are briefly highlighted.
Mitochondrial DNA Extracted from Eastern North American Wolves Killed in the 1800s is Not of Gray Wolf Origin
Wilson, P ; Grewal, S ; McFadden, T ; Chambers, R ; White, B., Canadian Journal of Zoology, 81 (May, 2003): 936-940 (5 pp)
We analysed the mitochondrial DNA (mtDNA) from two historical samples of eastern North American wolves: the last wolf reported to have been killed in northern New York State (ca. 1890s) and a wolf killed in Maine in the 1880s. These wolves represent eastern wolves, presently classified as the gray wolf (Canis lupus) subspecies Canis lupus lycaon, which were present well before the expansion of western coyotes (Canis latrans) into these regions. We show the absence of gray wolf mtDNA in these wolves. They both contain New World mtDNA, supporting previous findings of a North American evolution of the eastern timber wolf (originally classified as Canis lycaon) and red wolf (Canis rufus) independently of the gray wolf, which originated in Eurasia. The presence of a second wolf species in North America has important implications for the conservation and management of wolves. In the upper Great Lakes region, wolves of both species may exist in sympatry or interbreed with each other, which impacts the accuracy of estimates of numbers of wolves of each species within this geographic region. Furthermore, the historical distribution of the eastern timber wolf (C. lycaon), as revealed by these skin samples, has important implications for the reintroduction of wolves into the northeastern U.S. states, such as New York and Maine.
Mitochondrial DNA Variability in Italian and East European Wolves: Detecting the Consequences of Small Population Size and Hybridization
Randi, E.; Lucchini, V.; Christensen, M.F.; Mucci, N.; Funk, S.M.; Dolf, G.; Loeschcke, V., Conservation Biology, 14/2 (April 2001), 464 (10 pp)
The Italian wolf (Canis lupus) population has declined continuously over the last few centuries and become isolated as a result of the extermination of other populations in central Europe and the Alps during the nineteenth century. In the 1970s, approximately 100 wolves survived in 10 isolated areas in the central and southern Italian Apennines. Loss of genetic variability, as suggested by preliminary studies of mitochondrial DNA (mtDNA) sequences, hybridization with feral dogs, and the illegal release of captive, nonnative wolves are considered potential threats to the viability of the Italian wolf population. We sequenced 546 base pairs of the mtDNA control region in a comprehensive set of Italian wolves and compared them to those of dogs and other wolf populations from Europe and the Near East. Our data confirm the absence of mtDNA variability in Italian wolves: all 101 individuals sampled across their distribution in Italy had the same, unique haplotype, whereas seven haplotypes were found in only 26 wolves from an outbred population in Bulgaria. Most haplotypes were specific either to wolves or dogs, but some east European wolves shared haplotypes with dogs, indicative of hybridization. In contrast, neither hybridization with dogs nor introgression of non-native wolves was detected in the Italian population. These findings exclude the introgression of dog genes via matings between male wolves and female dogs, the most likely direction of hybridization. The observed mtDNA monomorphism is the possible outcome of random drift in the declining and isolated Italian wolf population, which probably existed at low effective population size during the last 100– 150 years. Low effective population size and the continued loss of genetic variability might be a major threat to the long-term viability of Italian wolves. A controlled demographic increase, leading to recolonization of the historical wolf range in Italy, should be enforced.
Modeling Emigration of Wolves from a Wilderness Area into Adjacent Agricultural Regions
Jensen, A.L.; Miller, D.H., Ecological Modelling, 175/2 (July 2004), 115 (6pp)
We developed and applied a simple population model to examine the relation between abundance of wolves in a wilderness area and the numbers that emigrate into adjacent agricultural areas and that may need to be removed on an annual basis. The model was applied using Minnesota wolf (Canis lupus) data. The gray wolf is emigrating from northern wilderness areas in the State of Minnesota into adjacent agricultural and urban areas to the south, and the costs of both wolf control and compensation to farmers for lost livestock is increasing as the number of wolves increases. Emigration reduces the number of wolves on a refuge to about 85% of the carrying capacity, and the number of wolves that emigrate into the agricultural area is 6% of the number on the refuge. With control on the refuge the number of wolves killed is about 10% of the carrying capacity or 24% of the wolves on the refuge, but control on the refuge results in less emigration. A conservative control strategy, in which abundance on the refuge is closer to the carrying capacity and emigration increases slightly, can increase the number of wolves on the refuge with a small increase in emigration.