olnokL A. Social diversity and promotion of cooperation in the spatial prisoner's dilemma game. Phys. Rev. E 77, 011904 (2008). 14. Houchmandzadeh. B. & Manacle. M. The fixation probability of a beneficial mutation in a geographically structured population. New Phys. 13.073020 (2011). 15. Frean. M.. Raine