Functional Interdependence in Coupled Dissipative Structures: Physical Foundations of Biological Coordination

Abstract

Coordination within and between organisms is one of the most complex abilities of living systems, requiring the concerted regulation of many physiological constituents, and this complexity can be particularly difficult to explain by appealing to physics. A valuable framework for understanding biological coordination is the coordinative structure, a self-organized assembly of physiological elements that collectively performs a specific function. Coordinative structures are characterized by three properties: (1) multiple coupled components, (2) soft-assembly, and (3) functional organization. Coordinative structures have been hypothesized to be specific instantiations of dissipative structures, non-equilibrium, self-organized, physical systems exhibiting complex pattern formation in structure and behaviors. We pursued this hypothesis by testing for these three properties of coordinative structures in an electrically-driven dissipative structure. Our system demonstrates dynamic reorganization in response to functional perturbation, a behavior of coordinative structures called reciprocal compensation. Reciprocal compensation is corroborated by a dynamical systems model of the underlying physics. This coordinated activity of the system appears to derive from the system’s intrinsic end-directed behavior to maximize the rate of entropy production. The paper includes three primary components: (1) empirical data on emergent coordinated phenomena in a physical system, (2) computational simulations of this physical system, and (3) theoretical evaluation of the empirical and simulated results in the context of physics and the life sciences. This study reveals similarities between an electrically-driven dissipative structure that exhibits end-directed behavior and the goal-oriented behaviors of more complex living systems.

Thermodynamics, organisms and behaviour

“…Coupled pairs of trees will tend to synchronize with either anti-phase or in-phase dynamics, and the selected mode also tends to be the one which produces a higher rate of entropy production for the prevailing circumstances [53]. When external constraints are imposed on one of the coupled trees its partner will tend to assume new dynamics that restore the rate of entropy production [82]. These examples demonstrate that when context changes, the system's dynamics change in ways that preserve the intrinsic end-directedness towards maximizing the rate of entropy production.…”