Scale-Free Networks
Scale-free topology creates organizations extremely tolerant of random disruptions but vulnerable to targeted attacks on critical hubs.
Scale-free networks exhibit extreme inequality in connections following a power law: P(k) ∝ k^(-γ), where γ typically ranges from 2-3. Most nodes have few connections while a few 'hubs' have many. In E. coli metabolism (~1,000 metabolites, ~2,000 reactions), a few metabolites (ATP, NADH, pyruvate, acetyl-CoA) are hubs participating in 50-100+ reactions, while most participate in only 1-3.
Functional advantages: (1) Extreme robustness to random failures - ~80% of random E. coli gene deletions have no measurable growth defect. (2) Vulnerability to targeted hub attacks - blocking ATP synthesis is immediately lethal. Scale-free topology emerges through preferential attachment: new connections preferentially link to existing hubs.
Business Application of Scale-Free Networks
Scale-free topology creates organizations extremely tolerant of random disruptions but vulnerable to targeted attacks on critical hubs. The Internet and WWW exhibit this pattern - random server failures rarely matter, but attacks on major hubs (Google, key infrastructure) are devastating.
Discovery
Albert-László Barabási and Réka Albert (1999)
Introduced scale-free networks and preferential attachment mechanism explaining power-law degree distributions in networks including the World Wide Web