In the case of aging, I believe a problem emerges from human ego and pet theories that are pushed to the exclusion of other complimentary parts of a multifactorial model
If we assume 3 billion base pairs, 1/100,000 transcription errors, but a high rate of intra-transcriptional proofreading, we get that figure down to about 0.3 mutations (wrong letter substitution) per cell division.