Higher-order assembly and emergent persistence in biology

Abstract

Biological systems often maintain functional organization for far longer than the molecular, cellular, or ecological interactions from which it emerges. How such organization persists despite rapid dynamics and continuous component turnover remains poorly understood. Here we review examples from genomics, neuroscience, development, and ecology, and distinguish the timescale over which organization assembles from the timescale over which it persists. Classical mechanisms based on slow variables, conserved quantities, or weak coupling explain important aspects of this separation, but persistence can also reside in relationships that remain stable as their underlying components change. We propose that interaction-modulating architectures provide one mechanism for this form of persistence by making interactions depend on additional components or context. A multilayer stochastic framework illustrates how these conditional relationships can be maintained across separated timescales. This perspective shifts the focus from the lifetime of individual components to the organization that persists through their turnover.