Luis Gomez (Personal webpage )

Institute for Theoretical Biology, Humboldt Universität zu Berlin, Berlin, Germany
Groups of animals perform highly coordinated collective behaviors that confer benefits to the individuals by facilitating social information exchange and protection from predators. Previous research has suggested that collective biological systems, ranging from the brain to animal groups, should operate in a special parameter region, where the system behavior undergoes a qualitative change, the so called critical points. Critical systems exhibit unique properties like maximal responsiveness to external stimuli and optimal propagation of information within the group. However, direct empirical support for critical dynamics and its functionality in animal groups (in particular in the wild) is mostly absent. In this work, we show that giant schools of sulphur mollies (Poecilia Sulphuraria) in their natural environment operate close to criticality, maximizing their discrimination capability of different environmental stimuli. Our results are based on analysis of spatio-temporal patterns of information transfer in animal groups at an unprecedented scale through quantification of giant escape waves encompassing up to 100000’s individuals in the wild, with the identified functional benefits of criticality being highly ecologically relevant in the context of the naturally occurring high predation pressure in the noisy and unpredictable environment.