Comparison of empirical distributions of selected features of isolated and connected nodes.

<p>Each plot shows two histograms of empirical probability density functions for a node feature, one for isolated and one for connected nodes. Top row (<b>A</b>, <b>B</b>, <b>C</b>) shows features in yeast, bottom (<b>D</b>, <b>E</b>, <b>F</b>) in human. <b>Features:</b> participation ratio (effective complex size derived from protein weights –<b>A</b>, <b>D</b>), proportion of proteins occurring in not more than 4 complexes (<b>B</b>, <b>E</b>), and number of direct interactions per protein member (<b>C</b>, <b>F</b>).