Abstract:

How do complex adaptive systems, such as life, emerge from simple constituent parts? In the 1990s Walter Fontana and Leo Buss proposed a novel modeling approach to this question, based on a formal model of computation known as lambda calculus. The model demonstrated how simple rules, embedded in a combinatorially large space of possibilities, could yield complex, dynamically stable organizations, reminiscent of biochemical reaction networks. In this talk I will revisit this classic model, called AlChemy, and show some new results.  We reproduced the original results and studied the robustness of those results using the greater computing resources available today. Our analysis revealed several unanticipated features of the system, demonstrating a surprising mix of dynamical robustness and fragility. Specifically, we found that complex, stable organizations emerge more frequently than previously expected, that these organizations are robust against collapse into trivial fixed-points, but that these stable organizations cannot be easily combined into higher order entities. We also studied the role played by the random generators used in the model, characterizing the initial distribution of objects produced by two random expression generators, and their consequences on the results. I will conclude with a discussion of possible applications of AlChemy to self-organization in modern programming languages and quantitative approaches to the origin of life.

Speaker: Dr. Cole Mathis (Arizona State University)

Speaker bio: Cole Mathis is an assistant professor in the Biodesign Institute and the School of Complex Adaptive Systems at Arizona State University. His research focuses on understanding the origin of life and detecting life beyond Earth. Before his current position Cole was a NASA postdoctoral fellow.

Host: Harrison Smith, ELSI.

Date: Wed. 12 Jun. 16:00-17:00 JST

Venue: Mishima Hall, ELSI (hybrid)