There is a scene in the animated blockbuster "Finding Nemo" when a school of fish makes a rapid string of complicated patternsan arrow, a portrait of young Nemo and other intricate designs. While the detailed shapes might be a bit outlandish for fish to form, the premise isnt far off. But how does a school of fish or a flock of birds know how to move from one configuration to another and then reorganize as a unit, without knowing what the entire group is doing? New research by University of Alberta scientists shows that one movement started by a single individual ripples through the entire groupa finding that helps unravel the mystery that has plagued scientists for years.
"It is known that there is a connection between the signals animals use to communicate with each other and their behaviour," said Raluca Eftimie, a graduate student in the U of As Centre for Mathematical Biology. "But until now, the connection between the complex spatial group patterns that we can see in nature and the different ways animals communicate, has not been stated explicitly."
For decades people have puzzled about how animalsfish schools, locust swarms, large flocks of birds--form large complex dynamical groups. It is clear individuals in the group are only communicating with nearby neighbours, but then the groups somehow emerge spontaneously with complicated patterns of their own. Eftimie and her co-authorsDr. Mark Lewis and Dr. Gerda de Vries, also from the Centre for Mathematical Biology housed in the U of As Department of Mathematical and Statistical Sciences--used a one-dimensional mathematical model to describe the formation and movement of animal groups. The work is published in the prestigious journal, "Proceedings of the National Academy of Sciences."
"Every individual in the group is influenced by movement of the individuals in its neighbourhood," said de Vries. Conversely, the individuals movement can influence the movement of the entire group.
Contact: Phoebe Dey
University of Alberta