About the Authors

Arne Traulsen

To whom correspondence should be addressed. E-mail: traulsen@fas.harvard.edu

Affiliation Program for Evolutionary Dynamics, Department of Organismic and Evolutionary Biology, Department of Mathematics, Harvard University, Cambridge, Massachusetts, United States of America

Martin A. Nowak

Affiliation Program for Evolutionary Dynamics, Department of Organismic and Evolutionary Biology, Department of Mathematics, Harvard University, Cambridge, Massachusetts, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: MN AT. Analyzed the data: MN AT. Wrote the paper: MN AT.