Martijn Huynen, Peter Stadler and Walter Fontana
RNA secondary structure folding algorithms predict the existence of connected networks of RNA sequences with identical structure. On such networks evolving populations split into subpopulations which diffuse independently in sequence space. This demands a distinction between two mutation thresholds: one at which genotypic information is lost and one at which phenotypic information is lost. In between diffusion enables the search of vast areas in genotype space, while still preserving the dominant phenotype. By this dynamics the success of phenotypic adaptation becomes much less sensitive to the initial conditions in genotype space.