John Henry Holland, a computer scientist who incorporated fields as diverse as economics, psychology, and biology into his work, including the study of ecosystems and immune systems, died peacefully on Aug 9 at his home in Ann Arbor, Mich. He was 86.
He pioneered the use of computer science by creating the genetic algorithm, a general computational algorithm used to improve problem solving by recombining and mutating previous solutions.
Dr Holland had a unique gift for bubbling down complex systems, such as world economics or ecosystems, to their essential elements, expressed in the form of rules that react to stimuli. Sets of interacting rules can then be used to solve two practical problems in artificial intelligence in developing models for these more complex systems: (1) how to design procedures that can learn appropriate behavior rather than have the behavior programmed in and (2) how to test new behaviors while avoiding system breakdown.
“John is rather unique in that he took ideas from evolutionary biology in order to transform search and optimization in computer science, and then he took what he discovered in computer science and allowed us to rethink evolutionary dynamics,” David Krakauer, the president of the Santa Fe Institute, wrote in a memorial article. “This kind of rigorous translation between two communities of thought is a characteristic of very deep minds.”
The author of several books, including Hidden Order: How Adaptation Builds Complexity (1995) and Emergence: From Chaos to Order (1998), he was a professor of psychology and of computer science and engineering at the University of Michigan, Ann Arbor, where he has been on the faculty since 1959. He also serves as an external professor at the Santa Fe Institute.
He received a bachelor’s degree in 1950 from the Massachusetts Institute of Technology, a master’s degree in 1954 and a doctorate in 1959 from the University of Michigan.