Complex Systems Science: From Cell Regulation to the Global Food Crisis

Insights and methods of complex systems science are transforming science and providing clarity about the impact of policies to address major societal problems. These conceptual and mathematical advances allow us to study interdependence, patterns, networks, multiscale behaviors, and “big data.” Here I focus on the application of these advances to real-world concerns. I discuss case studies from global socioeconomic systems and immune cell regulation. Our analysis of the global food crisis exposes the causes and consequences of rapidly increasing and volatile food prices. Food price spikes in 2007–2008 and 2010–2011 triggered food riots across the world and precipitated the Arab Spring. Our quantitative models of nonequilibrium markets show that the food price increases are due to (1) US biofuel quotas increasing the amount of corn to ethanol conversion and (2) deregulation of commodity trading enabling speculator trend-following to cause bubbles and crashes. Policy action by the US and the European Union could alleviate or even resolve these problems. Our analysis of cell regulation makes use of gene expression data to obtain whole-cell regulatory models describing the response of immune cells to dynamic perturbations. Moreover, we have shown that cell dynamics are controlled by attractor states with implications for understanding biological development and treating cancer. Our analyses demonstrate the opportunity for complex systems science to inform both social policy decisions and medical advances.