Carl Zimmer's profile of mathematical biologist Martin Nowak is well worth reading. Zimmer does a good job of describing the relevance of Nowak's modeling work, centered on the Prisoner's Dilemma:
Dr. Nowak and his colleagues found that when they put players into a network, the Prisoner's Dilemma played out differently. Tight clusters of cooperators emerge, and defectors elsewhere in the network are not able to undermine their altruism. "Even if outside our network there are cheaters, we still help each other a lot," Dr. Nowak said. That is not to say that cooperation always emerges. Dr. Nowak identified the conditions when it can arise with a simple equation: B/C>K. That is, cooperation will emerge if the benefit-to-cost (B/C) ratio of cooperation is greater than the average number of neighbors (K).
"It's the simplest possible thing you could have expected, and it's completely amazing," he said.
This work branches out into cancer etiology and social dynamics, among other things. My students will be reminded that I think the Prisoner's Dilemma is overrated -- but that's a topic for another day...
(not via Gene Expression, although Razib got there first!)
