The difference was highly significant for H o (Wilcoxon signed‐rank test, p < 0.01; Figure 3 a), and for F is , it was significantly lower on the mainland than on the islands (Wilcoxon signed‐rank test, p < 0.05; Figure 3 c).
This complexity might also be the reason why we could not find a significant relationship between the distance to the mainland and F is , although a positive trend was observed. 5 CONCLUSION The negative effect of either isolation or area size on genetic diversity has been documented in a large number of studies, but surprisingly few have combined the two landscape parameters or related it to the island biogeography theory.