Print PagePopulation size, gene flow, and genetic diversity affect the persistence of populations through time and space. Organisms with small body size and low vagility may be especially sensitive to perturbations in population connectivity, as populations can easily become geographically isolated and lose genetic diversity. One such vulnerable group is the phylogenetically diverse semifossorial snakes of the Great Plains. We used one of these snake species (Sonora semiannulata) to characterize population genetic structure and assess genetic diversity and population connectivity across Texas, Oklahoma, Colorado, and Kansas.
Results/Conclusions
We analyzed 160 amplified fragment length polymorphisms (AFLPs) to estimate population structure for 12 populations of ground snakes (a total of 228 snakes) across the region. We found that genetic diversity was high and population structuring was low, even across such a large spatial scale. This pattern may be explained by high rates of gene flow, recent range expansion, or a combination of both processes. We also found that rivers, but not manmade barriers such as interstate highways, were associated with decreased gene flow and genetic diversity. If other small fossorial species in the Great Plains show a similar lack of genetic structure, it may indicate that these populations can maintain connectivity despite habitat fragmentation and modification.
