Power Grids to Epidemics

Complex systems – from ecosystems and power grids to supply chains and social networks – can sometimes collapse or surge unexpectedly after minor disturbances. Understanding why this happens is a major challenge because these systems are made up of countless interacting parts. Small changes in one part of the network can ripple outward, creating outsized effects that are difficult to predict. Researchers have long suspected that certain patterns of interaction, or “motifs,” within these networks may play an outsized role in triggering these cascades.

A new study from FAU and international collaborators found that tiny clusters of interacting units can indeed act as amplifiers of disturbance. In ecological networks, just two or three species interacting in specific ways can explain a large portion of a system’s sudden reactivity. These findings suggest that small motifs are often responsible for the initial, dramatic responses in complex networks, whether in ecosystems, power grids or disease outbreaks. By identifying these critical clusters, scientists can better predict and potentially prevent cascading failures in a wide range of systems.

“We hope future research, perhaps inspired by this work, will deepen our understanding of which system properties arise from parts of a network and which emerge from the network as a whole,” said Ashkaan K. Fahimipour, Ph.D., co-author, an assistant professor in the Department of Biological Sciences, and a member of the Center for Complex Systems within FAU’s Charles E. Schmidt College of Science. “If we can figure out when small interaction patterns are responsible for big responses, we can focus attention on the most critical parts of complex systems and better anticipate how they might react to change.”

Read the press release.