<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hairston, N. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The Dynamics of two hybrid zones in Appalachian salamanders of the genus Plethodon</style></title><secondary-title><style face="normal" font="default" size="100%">Evolution, 46(4), 1992, pp</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CWT</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://cwt33.ecology.uga.edu/publications/2152.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">930-938</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Two zones of intergradation between populations of Plethodon have been studied for 18 and 20 years, respectively. The data consist of systematic scores of colors, made at least twice annually. Near Heintooga Overlook in the Balsam Mountains (Great Smoky Mountains National Park), the salamanders' cheeks are gray. Proceeding north toward the Smokies, there is increasing frequency and intensity of red color at two, four, and six miles. There has been no change in the scores at any location. The width of the zone and our failure to detect any change can be explained by assuming neutrality of the character and random diffusion during the probable time since contact between the two intergrading forms, which most likely took place after the Hypsithermal Interval, 8,000-5,000 BP. At Coweeta Hydrologic Laboratory in the Nantahala Mountains, Plethodon jordani and P. glutinosus hybridize at intermediate elevations. The lateral white spots of glutinosus decrease and the red on the legs ofjordani increases with elevation from 685 m to 1,052 m. At the higher elevation, the proportion of animals scored as &quot;pure&quot; jordani declined significantly from 1974 to 1990, an indication that the hybrid zone is spreading upward. The rate of spread is too great to be explained by random diffusion, so selection for glutinosus characters is the best explanation. The rate of spread of the hybrid zone indicates that hybridization began 60-65 years ago, at the end of the time of intense timbering. Such human disturbances have caused hybridization in other organisms.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1992-80807</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hairston, N. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Species packing in Desmognathus salamanders: experimental demonstration of predation and competition.</style></title><secondary-title><style face="normal" font="default" size="100%">The American Naturalist 127(3): 266-291</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CWT</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1986</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://cwt33.ecology.uga.edu/publications/914.pdf</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Salamanders have provided excellent material for ecological experiments. Long-lived animals with unusually stable populations, they conform to the implied assumptions embedded in theories of community organization and of evolution under the influence of interspecific interactions. Many species are abundant enough to provide ample material for experiments, and in some areas, expecially the southern Appalachians, multispecies associations among the family Plethodontidae are available for testing hypotheses about the organization of communities and the coevolution of their constituent species.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1986-81024</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hairston, N. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Species packing in the salamander genus Desmognathus: what are the interspecific interactions involved?.</style></title><secondary-title><style face="normal" font="default" size="100%">The American Naturalist 115(3): 354-366</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CWT</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1980</style></year></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The present paper presents evidence that questions previous interpretations and indicates that predation in and near streams has been more important than competition as the significant force in determining the evolution of the genus and the present structure of the community. The evidence consists of the size relationships, which are the reverse of what would be expected if competition had required increasing efficiency, the relative abundance of salamander predators in aquatic and terrestrial environments, and the failure of a majority of predictions about habitat shifts and size relationships when the predictions are based on the assumption of interspecific competition.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1980-81218</style></accession-num></record></records></xml>