Figure 3.

Expanding and evolving population in the clumped landscape. Expansion is heading towards right. Points denote the patches and lines show the movement paths of dispersing individuals (grey lines depict unsuccessful dispersers). A transition between core subpopulations with neighbourhood dispersers and margin populations with long-distance dispersers is shown (at the end of 5000th generation). Three sections are magnified to show some characteristic processes taking place during the expansion. (a) Core population of short-range dispersers. (b) Less risky, local dispersers re-emerging in relatively recently established populations owing to mutation. (c) Freshly colonized patches consisting only of long-range dispersers. Number of grey dotted lines compared with solid lines illustrates the high mortality of the risky dispersers.