Network Motifs: Simple Building Blocks of Complex Networks

TLDR

Complex networks are studied across many fields of science. To uncover their structural design principles, we defined “network motifs,” patterns of interconnections occurring in complex networks at numbers that are significantly higher than those in randomized networks. Motifs were identified in biochemical, neurobiological, ecological, and engineering networks, with distinct sets in ecological food webs versus genetic networks and the World Wide Web, yet similar motifs appeared in information‑processing systems, suggesting that motifs define universal network classes and that this approach can reveal the basic building blocks of most networks.

Abstract

Complex networks are studied across many fields of science. To uncover their structural design principles, we defined "network motifs," patterns of interconnections occurring in complex networks at numbers that are significantly higher than those in randomized networks. We found such motifs in networks from biochemistry, neurobiology, ecology, and engineering. The motifs shared by ecological food webs were distinct from the motifs shared by the genetic networks of Escherichia coli and Saccharomyces cerevisiae or from those found in the World Wide Web. Similar motifs were found in networks that perform information processing, even though they describe elements as different as biomolecules within a cell and synaptic connections between neurons in Caenorhabditis elegans. Motifs may thus define universal classes of networks. This approach may uncover the basic building blocks of most networks.