I read that a lot of aging is caused by DNA and mtDNA getting damaged, I was wondering if anyone knew of how much it gets damaged, like say if someone is X years old then the average cell's DNA is Y% correct of what it was originally. Or are changes to DNA much more rare, and if a small change happens does it turn into a cancerous cell or do small changes happen often with no apparent consequences. Same questions for mtDNA. If someone wanted to preserve both types of DNA with no deterioration, what would be the way to do it? I see a lot of companies that preserve DNA for parental testing and stuff, but I am not sure if they preserve it perfectly or just good enough to do their testing.