Evidence for adaptive divergence between the Rhine and the Rhone and for adaptive introgression of S. rhodanensis variants into sympatric S. trutta in the Rhone. a) Bayescan results: Logarithm of the posterior odds (PO) against FST for all AFLP markers in all three pairwise comparisons between S. trutta from the Rhine (Rhi) and the two species, S. rhodanensis and S. trutta, occurring in sympatry in the Rhone (Rho). Seven markers (in red) were detected as outliers in both comparisons across the drainage boundary but not between the two species within the Rhone. For these markers, the average band frequency in each group is given in panel b).
Keller et al. BMC Evolutionary Biology 2012 12:210 doi:10.1186/1471-2148-12-210