Where are bottlenecks in NK fitness landscapes?

Usually the offspring-parent fitness correlations is used to visualize and analyze some characteristics of fitness landscapes such as evolvability. In this paper, we introduce a more general representation of this correlation, the fitness cloud (FC). We use the bottleneck metaphor to emphasis fitness levels in landscape that cause local search process to slow down. For a local search heuristic such as hill-climbing or simulated annealing, FC allows one to visualize the bottleneck and neutrality of landscapes. To confirm the relevance of the FC representation we show where the bottlenecks are in the well-known NK fitness landscape and also how to use neutrality information from the FC to combine some neutral operator with local search heuristic.