Figure 6From: Factors and processes shaping the population structure and distribution of genetic variation across the species range of the freshwater snail radix balthica(Pulmonata, Basommatophora)Test on heterogeneity in population differentiation among central vs. marginal populations. Shown are the mean FST (+/- s.d.) in the recent expansion area (exp), the Holocene expansion area (hol) and the LGM refugia (ref). There is a significantly stronger structure in the expansion area than in both other areas (1000 simulations, p < 0.001 for both comparisons). The comparison between hol and ref was not significantly different.Back to article page