Network theory is hot. “As an intellectual approach, network theory is the latest symptom of a fundamental shift in scientific thinking, away from a focus on individual components — particles and subparticles — and toward a novel conception of the group. ‘In biology, we’ve had great success stories — the human genome, the mouse genome. But what is not talked about is that we have the pieces but don’t have a clue as to how the system works. Increasingly, we think the answer is in networks’.”