I'm not strong in biology, so bear with me on this:
I've been reading that as we age, our DNA is damaged by internal (e.g. errors during replication) and external (e.g. sun damage or radiation) factors.
If you take, say, an 80 year old, can you find DNA in their body that's the same as when they were a newborn? What kind of cells would have undamaged DNA?
Is DNA damage distributed evenly across the body or will some parts have more damage than others?
Is there any published data on how much DNA damage an average person accumulates over their lifetime? I'm not sure how this can be quantified, but I'm wondering if there has been any study on gauging damage.