Landscape variables that best explain genetic differentiation may not also best explain dispersal patterns, but many studies use genetic differentiation as a proxy for dispersal. I tested the effects of landscape on both genetic differentiation and dispersal in parallel, to explore whether landscape effects on genetic differentiation between populations and landscape effects on dispersal would be comparable in such contexts. I used circuit theory (Circuitscape) and least cost transect analysis to evaluate the effects of landscape on both movement and genetic differentiation of the butterfly, Parnassius smintheus, in the Jumpingpound Ridge study system. Circuit theory and least cost transect analyses did not identify the same best predictors to explain genetic differentiation and dispersal data. Circuit theory produced more accurate results with higher precision. Genetic differentiation should not be used as a sole proxy for dispersal in studies of landscape effects, but should be supplemented by more direct measures of dispersal
