Supplemental Figure 1.  Rubustness to noise analysis.  We added increasing levels of Gaussian noise to each organisms’ dataset with 0.01σ (blue circles), 0.1σ (pink squares), 0.5σ (yellow triangles), and 1.0σ (light blue crosses).  Shown is the negative log P-value of an interaction in the original network (x-axis) plotted against the interaction’s P-value in the network constructed from the noise-added data (y-axis).