Fig. 3

Neighbour joining cluster analyses (Sørensen dissimilarities) based on the occurrence of 471 genetic lineages. We used deeply divergent (i.e. old) genetic lineages (a–c; level I including 213 lineages) and such distinguished by shallow differentiations (i.e., referring to a younger time frame) (d–f, level II representing 258 lineages) for 78 species among 17 areas (A–S) as defined in Fig. 2. Trees in a and d are unrooted; in b and e rooted in the Po Plain; in c and f rooted in southern Sicily. Numbers show the percentage of bootstrapped trees (1,000 replicates) corroborating the focal split. Colours link areas consistently clustering together. The dark red square is highlighting the closest link of Sicily (M, N, O)