DNA's "half-life"
"By comparing the specimens ages and degrees of degradation, the scientists calculated DNAs half-life. After 521 years, half of the bonds that bind nucleotides together break, and in another 521 they would break again, and so on."
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By comparing the specimens ages and degrees of degradation, the scientists calculated DNAs "half-life". After 521 years, half of the bonds that bind nucleotides together will have broken, and in another 521 half of those left intact would have themselves broken, and so on. Even beaking a few bonds (i.e. in the first few years) may well render the DNA "useless".
(c.f.radioactive decay)
