| Summary |
The influence of historical biogeographic events on mtDNA variation in contemporary populations of southeastern crowned snakes was investigated by examining patterns of mtDNA divergence. The crowned snakes. Tantilia, range from the United States to Argentina. Traditional taxonomic classification recognizes three species in the southeastern United States, which form the coronata complex. Tantilla coronata is widespread in the southeastern United States, but is absent from peninsular Florida, where T. oolitica and T. relicta occur. Tantilla relicta currently comprises three subspecies: Tantilla r. relicta, T. r. neilli, and T. r. pamlica. All three subspecies are associated with the state's highland sand ridges, which were formed by fluctuating sea levels during the Pliocene and Pleistocene epochs. Twenty-eight snakes were examined and fifteen unique haplotypes were revealed using sequence analysis of the mitochondrial cytochrome h gene. MtDNA divergence patterns do not support prior systematic classification for the coronata complex. However, sequence variation does exhibit geographic structure. Hence, it is likely that vicariant events during the Plio-Pleistocene played a major role in shaping genetic patterns observed within the coronata complex. |
