Presentation Information
[SS14-03]Anticipating regime shifts in biological complex systems using network analysis
*Naoki Masuda1 (1. State University of New York at Buffalo (United States of America))
Keywords:
networks,dynamics,bifurcations
Complex biological dynamical systems often show sudden major changes, or tipping points, as the system gradually changes. Examples include mass extinctions in an ecosystem and aggressive progression of a disease in a human body. Exploiting critical slowing down phenomena among other things, various early warning signals (EWSs) that anticipate tipping events before they occur have been developed. In fact, many biological systems of our interest in this context form networks. How to construct EWSs for network systems is an underexplored question. We present heuristic and mathematically grounded methods to select sentinel nodes in a given network to construct good EWSs. We show that carefully chosen small subsets of nodes can anticipate transitions as well as or even better than using all the nodes under a wide variety of conditions. We further address the case in which one cannot use too many observations from each node for forming EWSs, expanding "spatial" EWSs that have been examined in particular in theoretical ecology research community. Lastly, while the main focus of this presentation is on systems showing either saddle-node or transcritical bifurcations, we discuss potential applications of these methods for biological network oscillations, which may emerge via Hopf bifurcations.