ical Population Biology journal home pa go: ..vww.elscvier.comflocateApb A two-player iterated survival game John Wakeley a.*, Martin Nowak a'b'c 'Department of Organismic and Evolutionary Biology. Harvard University. Cambridge. MA, 02138. USA b Program for Evolutionary Dynamics. Harvard University. Cambridge. MA 02138. USA ' Department of Ma

viruses. They could also occur in natural population structures. 1IST Austria, A-3400 Klosterneuburg. Austria. 2 Program for Evolutionary Dynamics. Department of Organismic and Evolutionary Biology, Department of Mathematics, Harvard University, Cambridge, MA 02138, USA. These authors contributed equally: Andreas Pavlogiannis, Josef Tkadlec. Co

s Ibsen-Jensen Krishnendu Chatterjee ' , and Martin A. Nowak' 'IST Austria. Klosteineuburg. A 3400. Austria. and 'Program for Evolutionary Dynamics. Department of Organismic and Evolutionary Biology. Department of Mathematics. Harvard University. Cambridge. MA 02138. USA Submitted to Proceedings of the National Academy of Sciences of the United