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Comment by JMTQp8lwXL | Hacker News Reader

Most of your cells are replaced every decade [0]. In replication, a fresh copy of DNA is created.

[0]: https://www.snopes.com/fact-check/does-body-replace-itself-s...

Most cells, yes. All? No. Most neurons in your brain will have to last your lifetime, and IIRC some of your stem cells will have to last with the same dna strands for most of your lifetime.

However if some bases in the DNA molecule get chemically degraded then error correction mechanisms should kick in and (mostly) correct them.

If your cells aren't replicating... what do they need DNA for?

Your DNA is read during the life of the cell for maintaining cell function, e.g, creating proteins.

The cells DNA is still the source of all information for it's functioning, when a cell has to make new protein it reads the sequence from the DNA first.

Over long enough time scales, replication errors and base pair flips will accumulate, and it's likely these effects will become problematic way before the stated in vitro half life of 521 years. However, since we're talking about technologically enhanced life anyway, this opens the door to employing correction mechanisms that will actively repair such defects in vivo. In the end though, risks keep accumulating, both external and internal to the body. Intelligent biological life without digital backups does not seem to be the right platform for surviving time spans in excess of, say, a few hundred years.

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