Primers in Complex Systems

"One of Choice's Outstanding Academic Titles for 2010" Deborah M. Gordon is professor of biology at Stanford University. She is the author of Ants at Work (Norton). How do ant colonies get anything done, when no one is in charge? An ant colony operates without a central control or hierarchy, and no ant directs another. Instead, ants decide what to do based on the rate, rhythm, and pattern of individual encounters and interactions--resulting in a dynamic network that coordinates the functions of the colony. Ant Encounters provides a revealing and accessible look into ant behavior from this complex systems perspective. Focusing on the moment-to-moment behavior of ant colonies, Deborah Gordon investigates the role of interaction networks in regulating colony behavior and relations among ant colonies. She shows how ant behavior within and between colonies arises from local interactions of individuals, and how interaction networks develop as a colony grows older and larger. The more rapidly ants react to their encounters, the more sensitively the entire colony responds to changing conditions. Gordon explores whether such reactive networks help a colony to survive and reproduce, how natural selection shapes colony networks, and how these structures compare to other analogous complex systems. Ant Encounters sheds light on the organizational behavior, ecology, and evolution of these diverse and ubiquitous social insects. "In her new book, written in a lively style and accessible to a general audience, Gordon describes the sophisticated experiments that led her to intriguing insights about how an ant colony can solve vital problems, such as finding the shortest path to the best food source, allocating workers to different tasks or defending a territory from rivals." "This volume provides a well-focused review of how complex biological systems develop and function, with applications well beyond understanding ant colonies. It may compel behavioral and community ecologists, as well as other non-biologists, to consider new perspectives in understanding interacting systems." "This concise, well-written book will be of interest to biologists and complexity scientists, but is written to also be accessible to non-scientists. . . . Ant Encounters is an enjoyable read, full of neat experiments and lively anecdotes illustrating the scientific points."---Elva J. H. Washington, Trends in Ecology and Evolution "[T]he good and easy to understand introduction to the role of interaction networks in colony behavior--or ants as a natural complex system based on interactions networks--as well as the style of writing makes the book an entertaining read."---Heike Feldhaar, Basic and Applied Ecology "Deborah Gordon has produced a delightful and scholarly introduction to ant colony organization that teaches as it entertains. Building on decades of observation, experimentation, and simulation, she convincingly demonstrates that ants form self-organized communities, in which individual tasks change dynamically as conditions and interaction networks shift. Placing her work in a historical framework that reaches from Darwin to political theory, Gordon conclusively makes the case that ant societies are model systems for the study of collective behavior."-Simon A. Levin, Princeton University "Deborah Gordon's amazingly detailed book on the complex web of interactions in ant colonies makes fascinating reading for anyone who is curious about the world around us. And-even more interestingly from my point of view-this book provides rich fodder for understanding other kinds of collective intelligence, from neurons in the brain to human societies linked by the Internet."-Thomas W. Malone, Massachusetts Institute of Technology "Ant societies are like-and not like-human societies. Deborah Gordon's new book takes on these fascinating contradictions and achieves the rare balance of serving as an introduction for those wishing to learn about the wonders of

Scott E. Page is the Leonid Hurwicz Collegiate Professor of Complex Systems, Political Science, and Economics at the University of Michigan and an external faculty member at the Santa Fe Institute. He is the author of The Difference: How the Power of Diversity Creates Better Groups, Firms, Schools, and Societies (Princeton). This book provides an introduction to the role of diversity in complex adaptive systems. A complex system--such as an economy or a tropical ecosystem--consists of interacting adaptive entities that produce dynamic patterns and structures. Diversity plays a different role in a complex system than it does in an equilibrium system, where it often merely produces variation around the mean for performance measures. In complex adaptive systems, diversity makes fundamental contributions to system performance. Scott Page gives a concise primer on how diversity happens, how it is maintained, and how it affects complex systems. He explains how diversity underpins system level robustness, allowing for multiple responses to external shocks and internal adaptations; how it provides the seeds for large events by creating outliers that fuel tipping points; and how it drives novelty and innovation. Page looks at the different kinds of diversity--variations within and across types, and distinct community compositions and interaction structures--and covers the evolution of diversity within complex systems and the factors that determine the amount of maintained diversity within a system. • Provides a concise and accessible introduction • Shows how diversity underpins robustness and fuels tipping points • Covers all types of diversity • The essential primer on diversity in complex adaptive systems "Scott Page effectively illustrates the multiplicity of results from diverse aspects of complex systems. While all too many social scientists have tried to focus on making analysis simple, Page points out that this overlooks the great variety of relevant material in our social worlds. I am looking forward to having my students read it in my graduate seminar and encourage others to do so as well."-Elinor Ostrom, winner of the Nobel Prize in economics "At once clear and precise, Page not only makes a persuasive case for the advantages of diversity in biological, ecological, and social systems alike, but also provides the reader with the analytical tools necessary to engage real-world debates in a rational, even quantitative manner. The result is a valuable primer on a difficult and important subject."-Duncan J. Watts, author of Small Worlds: The Dynamics of Networks between Order and Randomness "Scott Page has performed a remarkable work of synthesis. The concepts of diversity and its implications for performance and growth are common to many fields, especially biology and economics. Page has drawn these illustrations together and shown the common elements and how each field illuminates others."-Kenneth J. Arrow, winner of the Nobel Prize in economics "Page engagingly seduces readers into rather deep ideas in complex systems, including sophisticated mathematical formulas, by using a relaxed style with lots of examples. Yet the treatment is rigorous."-Simon A. Levin, Princeton University "One of the book's many strengths is that it draws upon insights from seemingly disconnected areas of research and shows how they can be viewed within a common framework. Page's style is lively and conversational, making challenging subject matter quite readable, but without any sacrifice of rigor. He manages to convey both the excitement and difficulty of analyzing complex systems and the role of diversity within them."-Rajiv Sethi, Barnard College, Columbia University

"Winner of the 2012 First Place Cover/Jacket in the Professional, Scholarly Series, New York Book Show" Ricard V. Solé is research professor and head of the Complex Systems Lab at Pompeu Fabra University and external professor at the Santa Fe Institute. He is the coauthor of Signs of Life (Basic) and Self-Organization in Complex Ecosystems (Princeton). Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation of diverse ecosystems, the book illustrates the power of simple models to reveal how phase transitions occur. Introductory chapters provide the critical concepts and the simplest mathematical techniques required to study phase transitions. In a series of example-driven chapters, Ricard Solé shows how such concepts and techniques can be applied to the analysis and prediction of complex system behavior, including the origins of life, viral replication, epidemics, language evolution, and the emergence and breakdown of societies. Written at an undergraduate mathematical level, this book provides the essential theoretical tools and foundations required to develop basic models to explain collective phase transitions for a wide variety of ecosystems. "Solé has compiled an interesting overview of the vast amount of real world systems in which phases play a role. It is a good introduction to the topic and the great variety of applications is inspirational. Phase Transitions is a good read for the JASSS audience interested in if, how, and when abrupt changes may occur--either as risks for collapse or as opportunities for salvation."---Emile Chappin, Journal of Artificial Societies and Social Simulation "Mean-field approaches constitute an elegant and considerable contribution to complex systems studies, and I commend Sole for his rigorous presentation."---Lael Parrott, BioScience "This ambitious book provides an elegant and much-needed synthesis to many of the ideas that have come to define the field of complex systems and their applications to nature and society. It makes an important contribution to the field, especially for researchers and students looking for an overview of the literature and entry points for research."-Luis Bettencourt, Los Alamos National Laboratory and the Santa Fe Institute "This clear and easy-to-follow book is a valuable compilation of systems showing phase transition phenomena that have become more and more important in understanding natural and man-made complex systems. It is a useful addition to the already existing literature."-Stefan Thurner, Medical University of Vienna

Daniel L. Stein is professor of physics and mathematics at New York University's Courant Institute of Mathematical Sciences. His books include Spin Glasses and Biology. Charles M. Newman is professor of mathematics at NYU's Courant Institute of Mathematical Sciences and at the University of California, Irvine. His books include Topics in Disordered Systems. Spin glasses are disordered magnetic systems that have led to the development of mathematical tools with an array of real-world applications, from airline scheduling to neural networks. Spin Glasses and Complexity offers the most concise, engaging, and accessible introduction to the subject, fully explaining what spin glasses are, why they are important, and how they are opening up new ways of thinking about complexity. This one-of-a-kind guide to spin glasses begins by explaining the fundamentals of order and symmetry in condensed matter physics and how spin glasses fit into--and modify--this framework. It then explores how spin-glass concepts and ideas have found applications in areas as diverse as computational complexity, biological and artificial neural networks, protein folding, immune response maturation, combinatorial optimization, and social network modeling. Providing an essential overview of the history, science, and growing significance of this exciting field, Spin Glasses and Complexity also features a forward-looking discussion of what spin glasses may teach us in the future about complex systems. This is a must-have book for students and practitioners in the natural and social sciences, with new material even for the experts. "The challenge that Stein and Newman faced in creating this book . . . was to write for a broad range of readers and still offer interesting depth. As they state in the preface, they are aiming for a reading level that is between Scientific American and research journals. This reviewer believes they have succeeded. . . . Stein and Newman write well and keep the mathematics to a minimum." "[A] surprisingly broad field of view is visible through the lens of the classical, equilibrium using spin glass and the authors are able to use it to explore many fascinating topics. Stein and Newman have written an excellent introduction to the field of spin glasses and the many ramifications of spin glass theory outside of condensed matter physics and statistical mechanics. Experts and novices alike will find this book interesting and useful."---Jonathan Machta, Journal of Statistical Physics "Spin Glasses and Complexity is not a journalistic book that merely reports on the subject. Based on profound mathematical insights, here distilled into an incisive presentation, it represents the fruit of the lifelong commitments two experts have made to spin-glass theory within and beyond physics. . . . Spin Glasses and Complexity is unique in successfully bringing this thrilling theme to a broader scientific audience."---Stefan Boettcher, Physics Today "[T]he work is well presented and the reader will surely find it both inspiring and interesting."---Marco Castrillon Lopez, European Mathematical Society "Well presented and the reader will surely find it both inspiring and interesting."---Marco Castrillon Lopez, European Mathematical Society "This excellent book fills a unique and valuable niche. It is a great introduction to some fascinating physics, emphasizing the fundamental concepts and the connections to other complex systems. There are lots of technical volumes on spin glasses, but no other book works at this nonmathematical level, certainly not while still being so accurate and insightful."-Cosma Shalizi, Carnegie Mellon University "This primer builds the theory of spin glasses, starting with the real physical systems and experiments that inspired the theory. Stein and Newman work hard to make this material accessible to nonphysicists, and they write in an entertaining and friendly way. Even as a physicist I learned a fair amount."-Cr