Figure 7

Structural stability: disintegration of collective information depends on the secondary structure, example hairpin. We represent, for each position along the sequences in the population, the total number of secondary structures presenting each structural state. In this case, we have only considered those sequences that do not fold into the hairpin structure. Subplots correspond to increasing values of the mutation rate μ = 0.04 (a), μ = 0.05 (b), μ = 0.06 (c), and μ = 0.07 (d). This representation permits to identify robust motifs in the secondary structure, that is, structural parts that are maintained at high values of μ. Curves have been calculated from the asymptotic state (after 6000 generations) of 25 simulations for a population with N = 602. From the obtained 15050 structures, those folding into the target structure have been discounted: 1891 (a), 590 (b), 70 (c), 0 (d). Black dots denote unpaired positions ".", red triangles directed to the right correspond to upstream pairs "(", and green triangles directed to the left are downstream paired ")" nucleotides. The consensus structure is obtained by taking the most frequent state at each position.