Isolation by distance data

Isolation by distance refers to the idea that individuals may be spatially distributed across some region, with slow dispersal. In this situation, allele frequencies vary gradually across the region. The underlying structure model is not well suited to data from this kind of scenario. In practice, the inferred value of $K$, and the corresponding allele frequencies in each group can be rather arbitrary. Most individuals will have mixed membership in multiple groups. That is, the algorithm will attempt to model the allele frequencies across the region using weighted averages of $K$ distinct components. In such situations, interpreting the results may be challenging. However, the admixture model will work well for 1-dimensional isolation by distance, and also for hybrid zones.