Fig. 1From: Resource Competition and Coevolution in SticklebacksBeak size distributions of ground finches (Geospiza) on several Galapagos islands. Beak sizes of the small (G. fuliginosa) and medium (G. fortis) ground finch are more similar where each occurs separately, but are divergent where the species occur together. Reproduced from Lack (1947)Back to article page