3.3 Genetic divergence between populations
Genetic divergence among populations measured asF ST are summarized in Table 1 and Table S6. Average F ST among populations within metapopulations varied between 0.06 and 0.16 in the 1970-80 samples (past) and from 0.04 to 0.18 in the present samples and were significantly larger than zero in all lake systems at both points in time (all p<0.001; Table 1). Among non-sympatric populations,F ST ranged between 0.07-0.16 (past) and between 0.08-0.18 (present) while among sympatric populations (i.e., populations coexisting in the same lake) F ST spanned 0.05-0.10 (past) and 0.04-0.09 (present; Table 1). A significant change of F ST among populations over time was observed in three of the eight systems where we have more than one population per system (Table 1). One case shows significant increase ofF ST (Skåarnja 2; p=0.006; Wilcoxon matched pairs test; Table 1). In contrast, there was a statistically significant decrease of F ST in two of the below tree-line metapopulations (Jougdadalen and Hotagen 4; p=0.011 and 0.006, respectively; Wilcoxon matched pairs test; Table 1).