Relative complexity and similarity of AND, OR, A, B, and XOR environments as a graph. Node values correspond to the environmental complexity (squares, border thickness is proportional to the complexity). Pair-wise similarity is calculated as the Pearson correlation of nutrient presence between environments and corresponds to the edge value (red and blue represent correlation and anti-correlation, respectively). The environment of highest complexity, XOR, is part of a cluster of strongly correlated environments (A, B, OR, and XOR). Environment AND is the simplest one, and it is isolated from other environments (low or negative correlation).
Mozhayskiy and Tagkopoulos BMC Bioinformatics 2012 13(Suppl 10):S10 doi:10.1186/1471-2105-13-S10-S10