Fig. 3
Hierarchical demographic modeling approach for ecotype divergence. a We first established relationships among three allopatric European lineages from the Rhine, the upper Rhone and the Vistula rivers. The model 3a grouping populations into a West (Rhine, upper Rhone) and an East European (Vistula) clade was best supported by the data. b Next, we tested from which of the three lineages the majority of the genome of Lake Constance populations (L2, S2, NID) was derived. The best supported models suggest a majority contribution from the East European lineage for all populations (3Lv, 3 Sv). c Then, we tested whether other lineages contributed to Lake Constance populations (L2, S2, NID), with a model of contributions from both West European lineages best supported for all populations (3Lvx, 3Svx). d Finally, we compared different modes of ecotype divergence: primary divergence in situ, ecological vicariance, secondary contact and hybrid origin. For all pairwise lake-stream comparisons, a hybrid origin model clearly outperformed the other modes of divergence (Supplementary Fig. 8, Table 1). Pink rectangles highlight the best supported models. Little letters in model names denote models with admixture from West European lineages Rhone (‘o’), Rhine (‘i’) or from both (‘x’). Source data are provided as a Source Data file
