Using the Internet's first generation of Big Data, researchers like physicist Albert-László Barabási of Northeastern discovered hubs controlling the behavior of all large networks from protein regulation to webpages.
"Nature evolved the metabolic network for cells over 4 billion years," says Barabasi, "but that same architecture emerged in the World Wide Web after just a decade."
Different networks, same laws.
In a complex multicellular organism there is plenty of signaling between cells types and organs, and this can be viewed as a network.
But does network theory also apply to protein regulation within a cell? I should really ask; Has network theory been successfully applied to protein expression within a cell?
I ask this because it seems according to this clickable timeline template that 4 billion years ago, life was single-celled.
edit: There is a single link in the Wikipedia article that points to this paper, but the abstract is over my head, and I'm not sure if this is a one-off attempt, or if network theory is an established method that has useful success in explaining/understanding/predicting protein expression within cells.