This project investigates the mechanisms for promotion of cooperation in decentralized wireless networks. The main objective is to determine whether cooperation can emerge in these networks in the same way it emerges in biological systems. The approach is motivated by recent results in evolutionary biology which suggest that cooperation can be favored by natural selection, if a certain mechanism is at work. We are interested in promoting cooperation based on simple rules, in contrast to most of the approaches which enforce cooperation by using complex algorithms and require strategic complexity of the network nodes. We present a model of a wireless network as a graph, and associate benefits and costs with the strategy that the network users follow at a certain time instant (cooperation or defection). We define fitness function based on the amount of power each node has to transmit and allow the users to update their strategy based on the observed change of fitness. The objective is to demonstrate that cooperative behavior, if introduced by chance, can persists over time in the wireless network.