Figure 6. Cell-size limitation.

(a) Genome size and fitness of the last common ancestors for simulations with the number of sequences limited to 10 and 25 sequences. For each mutation rate four repetitions of a simulation (circles and stars) with a different seed and the average, are shown. Note that results under high mutation rates differ the least, suggesting a ‘natural’ upper bound for genome size. (b) Number of sequences (above) and the functional structures encoded (below), for both limitations with the four mutation rates. Blue bars are the total number of sequences and structures. Yellow bars depict the number of sequences coding for adapters (above) and functional structures guided by adapters (below). By restricting the number of sequences, redundancy is suppressed and adapter usage is promoted.