Cooperation level for population structures with different replacement graphs.

<p>Results are shown for the conventional NPD (Panels A and B) and the distributed NPD (Panel C). In each case, interaction graphs are constructed following the graph approach from rings (Panel A) or Barabási-Albert scale-free networks (Panels B and C) of order and mean degree . The replacement graph is given by the original graph from which the interaction bigraph is constructed (OG) or the unweighted, unnormalized weighted or normalized weighted projection of the interaction graph (UP, UWP and NWP, respectively).