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Collective search behaviour in chaotic flows
Colin Torney (graduate student) and Sepideh Bazazi (graduate student)
Department of Ecology and Evolutionary Biology
Locating the source of an advected chemical signal is a common challenge facing many living organisms. The task becomes particularly difficult when the medium of the flow is chaotic. This image shows how the location of a source can be achieved without assessing the spatial gradient direction, measuring the properties of the flow field, or performing complex calculations. Instead the autonomous, non-communicating individuals (shown as spheres) follow simple social interaction rules which are modified according to the local conditions they are experiencing. Through these context-dependent interactions the group is able to locate the source and displays an awareness of the environment not present at the individual level.

This image shows five snapshots of the time evolution of a group of sixty individuals progressing from a position on a filament to the source of the chemical. Each panel shows the view from above (left) and the concentration profile (right). The work demonstrates the ability of decentralized information processing systems to solve real world problems and also illustrates an alternative pathway to the evolution of higher cognitive capacity via the emergent, group-level intelligence that can result from simple low-level interactions.