Hyunju Kim, PhD - US grants

From the level of chemical reaction networks within cells to the social structures of higher organisms, biological systems seem to take advantage of distributed computation to perform a myriad of complex functions. However, rigorous quantification of how life stores, processes and propagates information at the various levels of organization observed in biological systems has remained elusive. In this project the PIs will utilize recently developed information-theoretic tools from complex systems research, typically applied to artificial life systems, to assess how a real biological system manages distributed information to perform a collective computational task. This research will provide new applications of mathematical and computational tools for use by scientists and will provide important insights in issues of broader concern such as colony collapse disorder observed in honeybees. The results will be disseminated to the general public through a variety of media as part of the outreach efforts of the PI and Co-Is.

Specifically, the PIs focus on characterizing information storage, processing, and propagation in colonial decision making as a rigorous case-study for understanding the physics of collective computation in living systems. The aim is to address several outstanding questions in insect behavior, by applying a novel theoretical framework treating collective decision making as a computation to the problem of collective nest site choice by the ant Temnothorax rugatulus. To this end, the investigators will implement a novel synthesis of two levels of theoretical investigation, agent-based modeling and information-theoretic analysis of experimental and simulated data sets, with experimental manipulation to determine the mechanisms of information processing among individuals that lead to global, emergent computation in Temnothorax rugatulus colonies. With this novel framework, the PIs will address several important outstanding questions about the physics governing collective choice, including the role of negative feedback and under what conditions collective wins over individual rationality. The research will provide one of the first detailed studies expanding the wealth of knowledge on emergent computation in complex systems to the biological realm. This study will inform our understanding of fundamental aspects of biological computation that will provide new perspectives on the physics of living systems by illuminating how life stores, processes, and propagates information. Due to the ease of manipulation of individuals within eusocial-insect societies, the PIs will be able to probe the minimal set of individual-level features necessary for spontaneous distributed computation.