The most important and interesting things in this world are complex systems, systems that emerge from the interactions of seemingly autonomous component subunits. Brains and the thoughts they entertain emerge from interacting neurons, bodies and their vitality from interacting cells, and societies from interacting people (or ants). How do interactions, distributed over time and space, make for seemingly intelligent complexity? This book offers some insight by examining certain aspects of the immune system together with several other types of complex systems. The immune system is an ideal theatre for inspecting the drama of complexity because we have more scientific information about this system's actors than is available for other systems. Knowing the character of the actors gives us indispensable insights into the logic of the system as a whole. Examples of prototypical problems that are treated in the book are these. (i) How do systems choose the right set of agents to perform appropriate actions with appropriate intensities at appropriate times? (ii) How in the immune system, ant colonies and metabolic networks does the diffusion and binding of a large variety of chemicals to their receptors permit coordination of system action? (iii) What advantages drive the various systems to complexity, and by what mechanisms do the systems cope with the tendency toward unwieldiness and randomness of large complex systems.

About the Editors

Lee A. Segel, Benson Professor of Mathematics, Weizmann Institute. Lee Segel studied mathematics and its applications, mainly to fluid mechanics, at Harvard, Cambridge University and MIT. Around 1970 he switched his interests to applications of mathematics in the biological sciences. He is Editor-in-Chief of the Bulletin of Mathematical Biology.

Irun Cohen, Professor, Immunology Department, Weizmann Institute.