Fig. 2

Plots of ancestral fractions from the Admixture cluster analysis for both sand lance species (top = A. tobianus; bottom = H. lanceolatus). Each vertical bar represents one individual, while the colors indicate the likelihood of this individual belonging to a particular ancestral population. K refers to the number of ancestral populations that were assumed to be present in the dataset. K = *indicates the most likely K. The asterisks in the sampling site heading of H. lanceolatus indicate fish from sampling sites with < 8 individuals that were removed for population-level analyses. Samples are sorted from the North Sea (left) to the Baltic Sea (right) sampling sites