The Neanderthal Problem

[-Chris-]

On 5/11/2026 at 8:24 PM, Percy said:

Some sources say DNA has a half-life

 

Your questions were great and I did a little bit of research on DNA half life. Half-life implies a physical constant, the radioactive decay of an atom. DNA decay is a chemistry change, dependent on the temperature, environment and other factors. I think half-life is a poor term for these changes under these conditions.

 

Quote

By analysing mitochondrial DNA (mtDNA) from 158 radiocarbon-dated bones of the extinct New Zealand moa, we confirm empirically a long-hypothesized exponential decay relationship. The average DNA half-life within this geographically constrained fossil assemblage was estimated to be 521 years for a 242 bp mtDNA sequence, corresponding to a per nucleotide fragmentation rate (k) of 5.50 × 10^–6 per year. With an effective burial temperature of 13.1°C, the rate is almost 400 times slower than predicted from published kinetic data of in vitro DNA depurination at pH 5.

This paper is the apparent source of the oft-quoted 521 years. Note they mention the temperature and the length of the base pair sequence being measured.

Dry permafrost frozen sources may contain recoverable amounts much older than expected based on this study.