Ubiquity of Entropy-Driven Local Organization

Soft-matter and biological systems of crowded objects exhibit local organization into preferred motifs. Locally organized motifs in soft systems can, paradoxically, arise from a drive to maximize overall system entropy. The emergence of entropy-driven local order has been directly confirmed in model, synthetic colloidal systems, however similar patterns of organization occur in crowded biological systems ranging from the contents of a cell to collections of cells. In biological settings it is unclear whether entropy acts to promote or inhibit local organization. Answering this is difficult because entropic effects are intrinsically collective, complicating efforts to isolate them. Here, we employ minimal models that artificially restrict system entropy to show that entropy drives systems toward local organization, even when the model system entropy is below reasonable physical bounds. By establishing this bound, our results suggest that entropy drives local organization in all crowded soft and biological systems of rigid objects.