A Drive towards Thermodynamic Efficiency for Dissipative Structures in Chemical Reaction Networks.

Kai Ueltzhöffer,Daniela Cialfi,Lancelot Da Costa,Karl Friston

doi:10.3390/e23091115

Abstract

Dissipative accounts of structure formation show that the self-organisation of complex structures is thermodynamically favoured, whenever these structures dissipate free energy that could not be accessed otherwise. These structures therefore open transition channels for the state of the universe to move from a frustrated, metastable state to another metastable state of higher entropy. However, these accounts apply as well to relatively simple, dissipative systems, such as convection cells, hurricanes, candle flames, lightning strikes, or mechanical cracks, as they do to complex biological systems. Conversely, interesting computational properties—that characterize complex biological systems, such as efficient, predictive representations of environmental dynamics—can be linked to the thermodynamic efficiency of underlying physical processes. However, the potential mechanisms that underwrite the selection of dissipative structures with thermodynamically efficient subprocesses is not completely understood. We address these mechanisms by explaining how bifurcation-based, work-harvesting processes—required to sustain complex dissipative structures—might be driven towards thermodynamic efficiency. We first demonstrate a simple mechanism that leads to self-selection of efficient dissipative structures in a stochastic chemical reaction network, when the dissipated driving chemical potential difference is decreased. We then discuss how such a drive can emerge naturally in a hierarchy of self-similar dissipative structures, each feeding on the dissipative structures of a previous level, when moving away from the initial, driving disequilibrium.

Highlights

We start by briefly reviewing the role of dissipation in self-organisation on one hand, and the role of thermodynamic efficiency in the emergence of interesting computational properties—a hallmark of biological systems—on the other
We end by highlighting a small explanatory gap, namely how self-organising dissipative processes might be driven towards thermodynamic efficiency
Contrary to the—still widely held—belief that life is a struggle against the second law of thermodynamics, recent advances in nonequilibrium thermodynamics successfully recast biological systems as a subclass of dissipative structures

Summary

Introduction

We start by briefly reviewing the role of dissipation in self-organisation on one hand, and the role of thermodynamic efficiency in the emergence of interesting computational properties—a hallmark of biological systems—on the other. Dissipative structure formation has been well understood for many systems in the nearequilibrium, linear-response regime, due to the work of Prigogine and colleagues in the 1960s and 1970s [9], leading to the notion of biological systems as a class of self-organising free energy-conversion engines [10]. It took several decades until thermodynamic equalities were derived that hold for small systems arbitrarily far from equilibrium. Energy levels and kinetic accessibility of potential final states being equal, outcome states with a higher dissipative history are favoured, leading to the coining of the term dissipative adaptation for such a selection process [16]

Methods

Results

Discussion

Conclusion