MASSIVE MUTATION RATE. “Mutation rates have been estimated by independent genetic and biochemical approaches to be in the range of 10(−3) – 10(−5) mutations introduced per nucleotide copied, almost a million-fold higher than standard mutation rates operating on cellular DNA. This difference led Holland et al. to emphasize in a seminal paper a number of disease implications of a rapidly evolving RNA world immersed in a far more static cellular DNA world.”
http://www.sciencedirect.com/science/article/pii/S0042682215001580