4 ms·
Would it theoreticaly possible to find frozen animals 120.000 years old with still intact DNA?
by holoduke 3y ago
Would it theoreticaly possible to find frozen animals 120.000 years old with still intact DNA?
- sedatk 3y agoYeah, DNA in ice has a half-life of a million years. Seems very much possible.
- wwwtyro 3y agoWhat does half-life mean in the context of DNA? One base pair corrupted / unrecoverable? Half of them?
- netcraft 3y agohalf life generally means that within the time frame 50% of the material will have been destroyed or changed. so it would mean that half of the dna might still be available after 1M years
- graycat 3y agoTo be meaningful, half-life needs a Markov assumption, i.e., that the past and future are conditionally independent given the present. Or, more simply, at each instant, forget the past and for predicting the future use only the present. Some interesting work in the many contexts where half-life works would be to say what the Markov property says about the mechanism of the decay or whatever are trying to predict in the context.
- monocasa 3y agoHalf of them. Which is still useful in biological samples that have billions of copies.
- amelius 3y agoYeah, you can still assemble a genome even if strands are broken. In fact this is done all the time as the size of the strands going into DNA sequencers are often only 100s or maybe 1000s of basepairs.
- delecti 3y agoWhere 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 https://en.wikipedia.org/wiki/Ancient_DNA#Non-human_aDNA
- dekhn 3y agoI'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 I believe the section you linked is out of date.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.
- Tagbert 3y agoPreservation 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-worm-possibly-revived-from-siberian-permafrost/ https://www.scientificamerican.com/article/46-000-year-old-w...
- sedatk 3y agoThat’s room temperature. Frozen DNA is significantly more resilient. https://www.pnas.org/doi/10.1073/pnas.0702196104 https://www.pnas.org/doi/10.1073/pnas.0702196104
- AmericanOP 3y ago[flagged]
- bagels 3y agoI don't think this is a factual response. This appears to be some cartoon?
- AmericanOP 3y agoRecent Netflix story arc about boxing a defrosted caveperson. I couldn't resist.
- mandmandam 3y agoNot even a caveperson - a 200 million year old dude who fights tyrannosaurs. It's ridiculous and it's awesome.
- dekhn 3y agoThe oldest frozen mastodon found is only 30K years ago. This isn't really "frozen animals" and everything was sort of mixed together so they had to compare remaining fragments to existing sequences: https://www.nytimes.com/2022/12/07/science/oldest-dna-greenland-species.html https://www.nytimes.com/2022/12/07/science/oldest-dna-greenl...
- tokai 3y agoNot an animal, icecore, or that old, but ancient plants has been grown from seeds from permafrost.[0] So who knows what might be found and analyzed from all the icecores. [0] https://www.theguardian.com/world/2012/feb/21/russian-scientists-regenerate-ice-age-plant https://www.theguardian.com/world/2012/feb/21/russian-scient...