Researchers reached the bottom of ice sheet at -2670M after 7 years of drilling

Re:Researchers reached the bottom of ice sheet at -2670M aft... by delecti on Monday July 31, 2023 @01:54PM (#36946350)

Where are you getting that figure? Everything I had ever read on the subject puts the half-life at more like 500 (five-hundred) years. While doing a quick double-check for this comment, it seems there was one sample with the unexpectedly long observed half-life of 15,000 years, still a couple orders of magnitude less than a million years. https://en.wikipedia.org/wiki/Ancient_DNA#Non-human_aDNA

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Re:Researchers reached the bottom of ice sheet at -2670M aft... by Tagbert on Monday July 31, 2023 @02:40PM (#36947002)

Preservation conditions might have some bearing.

This recent news article suggests nematodes actually surviving after 46K years in permafrost. https://www.scientificamerican.com/article/46-000-year-old-w...

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Re:Researchers reached the bottom of ice sheet at -2670M aft... by dekhn on Monday July 31, 2023 @02:37PM (#36946936)

I'm not an expert in this area but I do know a fair amount on the subject. I believe the section you linked is out of date.

The DNA we get back from old situations typically was preserved, by dryness/freezing, and it's still quite fragmentary. The actual "half life" of DNA is not that interesting- its the details of the DNA remnants that matter.

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Re:Researchers reached the bottom of ice sheet at -2670M aft... by sedatk on Monday July 31, 2023 @04:40PM (#36948470)

That’s room temperature. Frozen DNA is significantly more resilient. https://www.pnas.org/doi/10.1073/pnas.0702196104

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