Signs of Life: How Complexity Pervades Biology

If you've ever been in a traffic jam, chances are, you've also engaged in a coordinated, complicated activity with other drivers - without even knowing about it. They are called traffic density waves. How can that be? How can you engage in large-scale behavior and not know it? It happens because of emergent behavior that results from simple algorithms in our driving. It happens to you, just like it happens to ants, bees, and termites. These simple rules result in unexpected, large-scale order. It's what Sole and Goodwin would call "order for free."Sole and Goodwin begin with one of the best introductory summaries that I've seen of simple chaotic behavior in nonlinear systems. The interesting thing about these systems is the way in which complicated behavior results from repetition and feedback using simple rules. Later descriptions of biological systems carry this theme forward, and constitute some of the most interesting reading in this book. For example, in the chapter on "Ants, Brains, and Chaos," the authors describe a model that simulates the raiding patterns of army ants. Observing these insects from a distance, one might be inclined to wonder at the appearance of a higher purposeful component to the movement of colony. With simulations, however, the authors have argued convincingly that the basic patterns seen in the foraging of army ants result from relatively simple algorithms built into the individual insects. These simple algorithms, at the individual level, result in large-scale behavior that has no obvious causal connection to the algorithms that are their cause. A similar chapter on the human brain helps us see that our own intelligence is most likely the amazing consequence of emergent behavior resulting from the interconnections and interactions of an unimaginable number of connected neurons in our brains. As such, it begins to make sense that what we call "ourselves" is really an emergent property of cells that is as unrelated to individual members as the marauding patterns of army ants is to the simple algorithms operating on the level of individual insects.Yet another fascinating example from the insect world is that of mound-building termites and nest-building wasps like those that infest my barn each year. Again, with computer simulations, the authors illustrate that beautiful wasp-like nests can be created using automata with simple algorithms that belie the complexity of the structures that emerge from groups operating under simple rules. After reading page after page of examples, one begins to get the sense that self organization is a rule of nature. It seems to be everywhere - almost to the degree that we might marvel when it does not appear. This, I believe, is one of the underlying messages in "Signs of Life:" That the order and complexity we perceive is actually the result of simpler algorithms operating in (mostly nonlinear) systems with feedback. That there is a broad range of emergent properti

This is what overviews of scientific fields of research should be like. The book begins in a gentle manner with an introduction into non-linearity, chaos and complexity. Many somewhat detailed technical steps are shown in text boxes and there are many illustrations to try to convey the information to a casual reader.In fact, this book bridges the gap between general overviews (something like Gleick's "Chaos") and much more scholarly presentations ("Complexity : Metaphors, Models, and Reality"). I suspect some non-technical readers won't make it very far but that is more likely due to the fact that they spend too much time on things they don't understand. Many important aspects of complex adaptive systems in biology are reviewed using many different examples. Both theoretical and real-life examples are typically used to help make the point.It is evident that the authors not only really understand the subject, they are also passionate and have excellent writing skills. Kauffmann is cited frequently but I suspect that most who have read "Investigations" will likely get a much better idea of his thesis when they read this book.The only minor point: why no commentary on where we appear to be rushing? Or better yet, why nothing about the philosophical implications of complexity? Perhaps the authors wanted to keep this book as non-controversial as possible and thereby potentially have it as an "official" reference but I cannot see why people should be upset by drawing some conclusions. Unless, of course, it is simply because some of the conclusions are so scary.This book should be standard reading!

This is a very interesting book. Athough there is some available literature on the recent advances in complex systems, it is often too general for the readers interested in having a good picture of how the area is developed and what type of (really) new advances are taking place. I think that this book, together with some literature on chaos (particularly Ian Stewart's book "Does God Play Dice?") and self-organization (I would strongly recomend Coveney's book "The Arrow of Time") provides a very useful guide to some of the most interesting findings, particularly within biological sciences. Although the most recent breakthroughs in complex networks are not there (not surprisingly) and the range of topics is certainly broad, I think the authors did a pretty good job in presenting a well-defined picture of the importance of emergence and phase transitions in genetics, ecology, evolution and brain dynamics (to cite just a few). You might agree with their views or not, but I think their enthusiam is contagious and makes you seriouly consider these ideas. The boxes, even if not allways self-contained (more references in the final list would have been helpful) trigger further interest in knowing more about the underlying maths and physics. Given the limitations imposed by a popular science book, I think they did a good job. This book should be a must-read for everyone interested in complex systems but also to those who feel that the analytic (so called reductionist) view of reality needs to be complemented with a wider perspective. I am myself molecular biologist, and in spite of the success of my own field over the last decades, I think it's time for some fresh air. Both approaches are needed and this book can give you a first glimpse of why the two approaches are required. I enjoyed reading it and loved the final paragraph.

Sole and Goodwin bring together a host of biological phenomena that can be explained only through nonlinear dynamics, self-organization and complexity theory. Starting with the work of Kaneko and Ko, which shows that genetically identical E. coli cells placed on identical nutrient media nevertheless grow at different rates, they demonstrate that biological systems are exquisitely sensitive to initial conditions and to unpredictable internal fluctuations. This results from the interactional nature of all biological processes. The activity of a whole organism or system of organisms cannot be predicted by summing the isolated activities of its component parts. Complexity theory explains the discontinuities of form and behavior that characterize biological systems. The illustration of these ideas in "Signs of Life" ranges all the way from cell differentiation in slime molds and higher organisms to the interactional nature of metabolic processes, the self-organizing properties of the central nervous system, the organizations created by social insects, ecosystems in general, and the economic and cultural activities of human beings on the largest scale. Evolution is shown to be the product of interactional phenomena involving many species at least as much as the competition of individual organisms with members of their own species. The fractal nature of complexity, resulting from the iteration of simple but universal rules, is illustrated in boxed mathematical descriptions of the phenomena being discussed. What emerges from all this is a picture of the biosphere creating a huge array of diverse organisms and organizations of organisms in a manner that remains orderly and intelligible from the viewpoint of complexity theory. The writing is both clear and lively. "Signs of Life" illustrates the fruitfulness of the vision of a complex universe developed in recent years at the Santa Fe Institute, where Sole and Goodwin and many of the scientists whose work they describe have worked.

This book is very good because it shows you a very broad spectrum of phenomena in which emergence takes place (genetics, the brain, the ants, rainforests, virus, economics, etc.). Emergence happens when a system of simple and numerous parts does something you couldn't have predicted from a description of the parts. It's full of very well chosen examples of emergence in complex systems. If you don't understand what the science of complexity *really* is about, buy it! You certainly will understand after you read it, I can assure you.I've always hated books in which there's only text and more text. I need drawings, diagrams, things that SHOW you something and make well explained ideas even better! This book is perfect in that. Also, if you don't like mathematics, they are exclusively inside gray boxes, and you just look at them if you want, the explanation is good enough. And by the way, the boxes are just great!