Introduction

A revolution is underway in the physical sciences, based on insights from nonlinear dynamics, which includes the areas popularly known as chaos and complexity studies. As described in the previous chapters, this revolution is beginning to affect greatly the biological and medical sciences as well. Prominent examples are the discovery of deterministic chaos in physiological time series data, of fractal properties of living processes, and of dynamical information processing in single cells and coupled cell signaling networks. The key feature of this work is the treatment of a living system as a dynamical system of nonlinearly interacting elements. As I have proposed in the Introduction to this book, the field of biodynamics might therefore be defined as the study of the complex web of nonlinear dynamical interactions between and among molecules, cells and tissues, which give rise to the emergent functions of a biological system as a whole.

This concluding chapter reviews major characteristics of this quickly developing research area and explores implications for basic research, clinical applications and biological thinking. Before highlighting selected findings that emphasize the nonlinear dynamical view, I first draw attention to the nonequilibrium foundations of living processes.

Life as a dynamical, nonequilibrium process

Many standard textbooks of cell biology or biochemistry still stress ideas that are based upon biochemical reaction-diffusion processes for equilibrium conditions in closed systems. Yet, we now know that the decay to biochemical equilibrium is a poor representation of living systems.