RNA reproduction by iterative template-directed recombination. The simulation was repeated 100 times with 300X initial RNAs for 10,000X, 30,000X, and 100,000X reaction steps. Each value was plotted against different diversities of an initial RNA population X. (a) Probability that at least one recombination occurred during simulation. (b) Average recombination number per population size (300X) when recombination occurs. (c) Probability that at least one autocatalytic network formed and collective reproduction occurred during a simulation. (d) Probability that no autocatalytic network formed, but self-reproduction of an RNA occurred. (e) Maximum network size of emerged autocatalytic networks. The error bars indicate standard errors in all panels. The data of X = 2 was omitted from panels (b–e) because the sample size was insufficient due to the low probability of reaction; see panel (a).