Book Reviewed: Worlds Hidden in Plain Sight - Thirty Years of Complexity Thinking at the Santa Fe Institute by David C. Krakauer

Explaining the complexity of evolution in biological and non-biological systems

This is an edited book that discusses the evolutionary science of complex systems that includes diverse subjects as, matter (non-life) to life transitions, and evolution, which includes biological evolution, and evolution of, economics and technologies, educational system, rural and urban structures, political structures, and banking systems. There are 37 chapters from various teams active in complex science research, and many are from the Santa Fe Institute in New Mexico. The editor of this book is a leading researcher in the field, and I found many chapters very illuminating. This new and emerging area of science finds commonality in the birth and evolution in biology, economics and technology, and other systems.

The take-home message from this book is as follows: Biological and non-biological systems seem to be unrelated. However, when we consider concepts such as non-equilibrium thermodynamics, entropy, Shannon’s information theory and statistical mechanics, they yield surprisingly similar results for the evolution of life and non-life systems alike. From one perspective, dynamical systems can be viewed as obeying the laws of physics (and chemistry for biological systems). From another perspective, they can be viewed as processing information and the operation of non-linear statistical mechanics. This is how complex adaptive systems come into existence and solve problems to control its own environment. This is illustrated by an example of a robot that is trying to catch an irregularly bouncing ball. It must decide what information is relevant, and the best way to use that in a model of task, and how can it learn to perform that task in real time? Similar challenges are relevant to biological systems undergoing natural selection or to any system that processes information in order to adapt. The fact that the total information contains both order and disorder information. We must identify where order increased at the expense of disorder. A system that controls its environment successfully adapts by constructing models that allow it to decide what information is necessary and how to act on it.

Thermodynamics is not a dynamical theory, it offers no explanation for the mechanistic origins of its macroscopic variables, such as pressure, temperature, volume, entropy, etc. But statistical mechanics offers microscopic basis for these macroscopic variables. The statistical mechanics establishes the conditions for non-equilibrium states, that is for dynamical/irreversible processes for counting microscopic configurations of a system and then connecting to its macroscopic averages of thermodynamic/macroscopic variables. The evolution of pattern formation under these conditions becomes relevant in system learning. Then terms such as, ''individual species," the boundaries of "community," the functional scale at which to characterize the "ecosystems," and the interface between "natural selection and self-organization," becomes more meaningful.

It should also be emphasized that the methods of dynamical systems theory are derived from deterministic classical mechanics. In contrast, the methods of information theory are non-deterministic which are based on probabilities. An example should serve as a useful exercise; In some monkey societies, it has been observed and reported that individuals estimate the future cost of social interaction by encoding the average outcome of past interactions in special signals and then summing over these signals that help them to take next steps in social interactions!

The authors in the edited book help us take a closer view of the world we live in. The physical reality we see, and experience is not just a product of the laws of physics and chemistry but also information dynamics, statistical mechanics and thermodynamics of systems. The non-deterministic probability component of statistical mechanics is ever present. No body could have modelled the path of biological evolution if there were intelligent beings studying planet Earth 65 million years ago! Highly recommended to readers interested in understanding the parallels in biological and non-biological evolution.