Fig. 2From: Structuring evolution: biochemical networks and metabolic diversification in birdsSchematics of the connected global enzymatic network of carotenoid compounds (66 compounds, 97 enzymatic reactions) found in species under this study (Additional files 1 and 2). Green nodes show dietary carotenoids. The distinct shaded areas represent the module assignments for the 53 compounds expressed at least once across species’ networks using simulated annealing [71, 72]. The numbers in the squares for each module denote the module number that corresponds to the module assignments for each compound in Additional file 1c Back to article page