AFLP band frequencies for the five markers showing replicated associations with altitude. Estimated AFLP band frequencies in the 16 populations of European trout sampled along Alpine altitudinal gradients for five markers showing replicated patterns in each drainage. The shading indicates different major river systems (hatched=Rhone; light grey=Poschiavino; light grey with horizontal stripes=Ticino; dark grey=Rhine). Within drainages, sites are ordered by increasing altitude. Site identifiers correspond to Figure 1. Lines show fitted values from a logistic regression model calculated separately for each drainage.