In 1946 twenty-five pairs of Castor canadensis were introduced into the Isla Grande of Tierra del Fuego (Argentina). Thanks both to environmental conditions favorable for colonization and an absence of effective control measures, today the estimated abundance is about 100 000 individuals. We have conducted molecular analysis of beavers from three areas of the Archipelago of Tierra del Fuego, in order to characterize the genetic structure of the invasive population. Our results from AMOVA (Fst= 0.104, p < 0.001) suggest that geographical barriers and large distances could limit gene flow among the populations. In the Tierra del Fuego National Park subpopulation, we found a positive and significant autocorrelation out to 800 m (r = 0.193, p = 0.003) and... |