When a species disappears from a region, the rest of the ecosystem may flourish or collapse, depending on the role that species played. When a storm rolls across the coast, the power grid might reconfigure itself quickly or leave cities dark for days. A snowstorm might mean business as usual in a hardy city and a severe food shortage in another, depending on the distribution strategies of residents.
Each of these systems is a kind of network, with thousands of members and relationships linking them. Understanding how networks behave is key to ensuring their functioning.
With current network theory, scientists can predict a few simple trends, such as which web pages are likely to get more hits over time. Mostly, current models “flatten” the system to a list of points (nodes) and connections between them (edges). But the features that bestow a network’s true cohesion and character – such as the nuanced predator-prey dynamics in an ecosystem, hierarchies in a social community, or critical hubs in a distribution system – have eluded quantification.
A new four-year, $2.9 million grant from the Defense Advanced Research Projects Agency is supporting SFI research that will, the researchers hope, propel their understanding of networks to the next level.