Keyghobadi, N., J. Roland & C. Strobeck. (in press) 1999 Influence of landscape on population genetic structure of the alpine butterfly Parnassius smintheus (Papilionidae). Molecular Ecology


We developed four microsatellite DNA markers which we used to examine the relationship between landscape and population genetic structure among a set of populations of the butterfly Parnassius smintheus located in the foothills of the Canadian Rockies. Detailed information on dispersal of adult butterflies among this same set of populations was available. Simple and partial Mantel tests were used to examine the relationships between genetic distances, predicted rates of dispersal and a number of landscape variables, all measured pair-wise for seventeen sample sites. Nei's standard genetic distance was negatively correlated with predicted dispersal. We observed a significant pattern of isolation by distance at a very small spatial scale. The distance between sites that was through forest was a stronger predictor of genetic distance than the distance through open meadow, indicating a significant effect of landscape on population genetic structure beyond that of simple isolation by distance. Our results suggest that rises in tree-line in alpine areas, caused by global warming, will lead to reduced gene flow among populations of P. smintheus.