This book consists of 17 papers on the contributions of John Holland by a distinguished group of scholars from a wide range of fields, including the Nobel laureates Kenneth Arrow and Herbert Simon, and also Douglas Hofstadter, Brian Arthur, Robert Axelrod, and Melanie Mitchell. Holland is the father of genetic algorithms, the pioneering worker exploring "emergence," and one of the leaders of the sciences of complexity. Holland's work is especially important for economics and evolutionary biology, artificial intelligence and machine learning, artificial life, and cognitive science.