About the Authors

Martin A. Nowak

martin_nowak@harvard.edu

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

Benjamin Allen

Affiliations Program for Evolutionary Dynamics, Harvard University, Cambridge, Massachusetts, United States of America, Department of Mathematics, Emmanuel College, Boston, Massachusetts, United States of America, Center for Mathematical Sciences and Applications, Department of Mathematics, Harvard University, Cambridge, Massachusetts, United States of America

Competing Interests

We have read the journal's policy and have the following potential conflict: Liao et al criticize Nowak et al. (2010). Here we defend Nowak et al. (2010).

Author Contributions

Wrote the paper: MAN BA.