Rick Riolo, who for decades taught students the art and science of agent-based modeling, passed away on August 25 surrounded by his family after a long illness. Born on September 4, 1950, Rick served as a Research Scientist and Research Professor at the University of Michigan’s Center for the Study of Complex Systems. He was one of the most visible and influential researchers, mentors, and instructors in the interdisciplinary field of complex adaptive systems.
The author of more than 80 papers, Rick made substantial methodological and applied contributions. His University of Michigan (UM) Ph.D. thesis, supervised by John H. Holland, advanced the fields of evolutionary and computational learning. A world class computational scientist, Rick wrote broadly on evolutionary computation, writing numerous papers on genetic algorithms, genetic programming, classifier systems, and agent-based modeling. His co-authored applied work spans topics of such breadth as to inspire awe: organizational culture, phenotypic plasticity, urban sprawl, typologies of corn-belt farmers, HIV transmission, hospital infections, political coalitions, sea lampreys, food webs, Mongolian grasslands, primary healthcare, and forests.
In each case, research teams reached out to Rick to tap into his computational skills, his open and engaged mind, and his cooperative personality. Rick always had time for everyone. Given that he never asked for anything in return, it is fitting that one of his most cited papers is titled: Evolution of Cooperation without Reciprocity, which was published in Nature.
He was a co-founder and co-organizer of the Genetic Programming Theory and Practice (GPTP) Workshop and co-editor of each of its annual conference proceedings since 1996. When the NIH established an interdisciplinary network to use complex systems techniques to study issues of population health in 2011, Rick was appointed the lead complex systems modeler. He is coauthor for three of the papers in the recently published summary volume of this network’s research.
Rick was a member of the famous complex systems brainstorming BACH group, founded by the artificial intelligence pioneers Art Burks, Bob Axelrod, Michael Cohen, and John Holland. Recognizing the influence of the BACH group, UM established the Program for the Study of Complex Systems in the late-1980s with Rick as one of its first two faculty members.
When the university promoted the Program to become the Center for the Complex Systems (CSCS), Rick was again one of the first faculty hires and the teacher of its two core courses. In 1991 the NSF awarded CSCS a $3.5 million-dollar IGERT grant to fund Ph.D. dissertations that use complex systems techniques to study social science problems; 43 Ph.D. students were funded under this grant, all learned their complex systems techniques from Rick who served on the dissertation committees of many of these students.
In 2014, the University of Michigan held a conference in his honor, all speakers hailed Rick as the heart and soul of CSCS.
Outside of his academic work, Rick was an enthusiastic bicycle rider, taking 40-mile bike trips a few times a week. He biked the two miles from home to office rain or shine or blizzard. He and his daughter Maria once biked in tandem from Ann Arbor to the Maryland shores. The onset of a degenerative muscle disorder ended his biking days and led eventually to his retirement from CSCS. In the last two years, despite extreme difficulty in speaking and typing, Rick remained active on research projects on the formation of hierarchies and the structure of aquatic food webs. He is survived by his wife Sue Monet and his daughter Maria Riolo who recently earned her PhD in Applied and Interdisciplinary Mathematics from the University of Michigan.
The family obituary can be reached HERE.
The Bach Group.