This volume has its genesis in the activities of the DIMACS working group on Genetics and Evolution of Pathogens. This working group held a meeting on November 24-25, 2003 at Rutgers University, and we would like to express our appreciation to Zhilan Feng for organizing and planning this successful conference. The volume represents an expansion of the efforts of this working group, and contains papers from experts in the field who were unable to attend this initial meeting. We thank the three editors Zhilan Feng, Ulf Dieckmann and Simon Levin for their efforts in the organization of the volume, and we thank Bruce Levin for his insightful Preface and also the various authors who contributed to the volume.

The meeting was part of the 2002-2007 Special Focus on Computational and Mathematical Epidemiology, and was organized by one of a number of special focus research groups called ``working groups'' as part of the special focus. We extend our thanks to Martin Farach-Colton, Sunetra Gupta, Donald Hoover, David Krakauer, Simon Levin, Marc Lipsitch, David Madigan, Megan Murray, S. Muthukrishnan, David Ozonoff, Fred Roberts, Burton Singer and Daniel Wartenberg for their work as special focus organizers.

The meeting brought together researchers who approach the study of epidemiology from a variety of disciplines, some applied and some theoretical. These included computer scientists, mathematicians, statisticians, and biologists together with both descriptive and analytical epidemiologists. The goal of the working group as well as of this volume is the exploration of cross-disciplinary approaches to the study of topics related to disease evolution, and how they apply to the study of specific diseases.

DIMACS gratefully acknowledges the generous support that makes these programs possible. Special thanks go to the National Science Foundation, the James S. McDonnell Foundation, the Burroughs-Wellcome Fund, the Purdue University Mathematics Department and to DIMACS partners at Rutgers, Princeton, AT&T Labs - Research, Bell Labs, NEC Laboratories America, and Telcordia Technologies, and affiliate partners Avaya Labs, HP Labs, IBM Research, and Microsoft Research.

Fred S. Roberts

Robert Tarjan
Co-Director for Princeton