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Ok, to clear things up, what they found was a rock, literally a rock down to the molecular level, that is perfectly shaped as a dinosaur embryo. It reveals some
by tomohelix 3y ago
Ok, to clear things up, what they found was a rock, literally a rock down to the molecular level, that is perfectly shaped as a dinosaur embryo. It reveals some interesting similarities to birds and stuff and good for paleontology.
But none of this contain even a miniscule amount of meat or organic material or DNA of a dinosaur. Those already disintegrated aeons ago. DNA half life is around 500 years. After a million years, it would have degraded so bad you literally have nothing left to reconstruct no matter how much sample you discover.
If you start with an entire dinosaur, let say 10 tons, and let be generous and have 1% of that being DNA, you get 1e15 copies of the genome, assuming a 10Gb genome. After 25,000 years, you get less than 1 copy left. Now make it 25 millions years...
I know this "half-life" term is kind of a misnomer since unlike radioisotope where it is unaffected by environmental conditions, DNA "half-life" can be longer depending on things like temperature and pressure. But still, on the scale of millions of years, it becomes exceedingly improbable that we can find even 1 copy of a dinosaur genome left.
- jacquesm 3y agoThere was this: https://www.scientificamerican.com/article/possible-dinosaur-dna-has-been-found/ https://www.scientificamerican.com/article/possible-dinosaur... but it's been pretty quiet afterwards.
- tomohelix 3y agoAs expected honestly. They found "chemical signals" that indicate DNA in the fossil. Such thing can be anything, from contaminations to errorneous readings. To sequence that supposed "DNA" is a whole other level of technology. In fact, it would be so complex that unless they are hiding alien tech somewhere, I dare say we can't do it at all with our current level of technology.
- jacquesm 3y agoIf there is anything at all... it would pretty much require rewriting the book on DNA preservation, given what we know about this right now I'd say 'impossible' but if there ever is any solid evidence to the contrary I'll be more than happy to admit that I was wrong.
- lifthrasiir 3y agoResearchers explain that the markers cannot be of the microbial origin because they were chosen to only stain DNA in dead cells, and that those markers were highly concentrated at where DNAs would originally have been before the death. So assuming no other obvious mistakes, there may be short (6+ bp) but still readable DNA strands in the fossil.
- jacquesm 3y agoThat's so short though that it isn't really useful. It would be like piecing together a book given syllables.
- lifthrasiir 3y agoYeah, 6 bp would be too short to be useful. But something like 50 bp would be much more useful, and haven't yet been exactly precluded.
- lifthrasiir 3y agoThe original research [1, section 4] is slightly more cautious (but otherwise agrees): > It is tempting to suggest that we can now predict the temporal limits of DNA survival, and finally refute the claims of authentic DNA from Cretaceous and Miocene specimens. This is, however, not straightforward. One needs information on the number of template molecules in living tissues, and estimates of post-mortem DNA decay rates for each tissue type. However, the half-life predictions display the extreme improbability that an authentic 174 bp long mtDNA fragment of an 80–85 Myr old bone could have been amplified. I looked at the paper partly because I was interested in the possibility that some multi-base strands survive, even though such strands would be very short. The "half-life" here was measured by qPCR, where a relatively large amplicon (a fragment being amplicated via PCR) was used. So this study doesn't preclude a possibility of very short (~100 bp) strands surviving, though this would require most enzymes to be much less effective at breaking such strands. [1] https://royalsocietypublishing.org/doi/10.1098/rspb.2012.1745 https://royalsocietypublishing.org/doi/10.1098/rspb.2012.174...
- credit_guy 3y ago> DNA half life is around 500 years. After a million years, it would have degraded so bad you literally have nothing left to reconstruct no matter how much sample you discover. That article with the 521 half life of DNA was complete bull. In 2022 they found DNA from a 2 million year old mastodon [1]. The whole 521 year half life is something like "it was that in our sample, and we can't guarantee that the result generalizes". Good maybe for a high school science project, not good for a paper in Nature. [1] https://www.nature.com/articles/d41586-022-04376-y https://www.nature.com/articles/d41586-022-04376-y
- lifthrasiir 3y agoThe half-life of 521 years does allow for some million year old DNAs to be found. The original paper even noted this possibility in exceptionally good environments [1, section 4]: > Our results indicate that short fragments of DNA could be present for a very long time; at –5°C, the model predicts a half-life of 158 000 years for a 30 bp mtDNA fragment in bone. Even rough estimates such as this imply that sequenceable bone DNA fragments may still be present more than 1 Myr after deposition in deep frozen environments. It therefore seems reasonable to suggest that future research may identify authentic DNA that is significantly older than the current record of approximately 450–800 kyr from Greenlandic ice cores. [1] https://royalsocietypublishing.org/doi/10.1098/rspb.2012.1745 https://royalsocietypublishing.org/doi/10.1098/rspb.2012.174...
- mrb 3y agoAnyone knows what research came out after scientists recovered 70 million-year-old T. rex soft tissue back in 2005 ? I remembered being blown away by the fact we could have soft tissues instead of fossilized remains... https://www.nbcnews.com/id/wbna7285683 https://www.nbcnews.com/id/wbna7285683
- femto 3y agohttps://en.wikipedia.org/wiki/Mary_Higby_Schweitzer https://en.wikipedia.org/wiki/Mary_Higby_Schweitzer
- mrb 3y agoThanks! So not only preservation of soft tissue was confirmed, although the exact mechanism is not fully understood. But also there are "multiple lines of evidence for material consistent with DNA in dinosaur" found in fossils https://www.sciencedirect.com/science/article/abs/pii/S875632821201318X?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S87563...
- lostlogin 3y ago> multiple lines of evidence for material consistent with DNA in dinosaur After reading a paper I don’t think I’ve ever had a thought like this before: did they run that past a legal team before publication? That sounds like a lawyer wrote it.
- mrb 3y agoThe language surprised me too! I realize the researchers wanted to be extra cautious (enough to pass peer-review) and that's the reason I did a literal quote instead of paraphrasing.
- holoduke 3y agoAnd what about fossilized dna remains? Would it not possible to have somekind od crystalized structure if DNA?
- mcv 3y agoFossilized means turned to stone. Since DNA is not a crystal, I don't think crystalized DNA is in any way a thing. All the organic stuff, including the DNA, has gone and been replaced with stone in the same shape. But only the same macro shape not the same molecular structures.
- jjtheblunt 3y ago> But still, on the scale of millions of years, it becomes exceedingly improbable that we can find even 1 copy of a dinosaur genome left. what about imputing genomics from the phenotypically similar present day animals (birds, reptiles, whatever else)?
- calamari4065 3y agoYou'd essentially be designing a dinosaur genome from scratch
- bryanrasmussen 3y agoOK but if you throw "AI" into that somewhere you'll have funding!
- 0xEF 3y agoIf anyone needs me, I'll be squatting the opendino.ai domain waiting for my payday.
- KingLancelot 3y ago[dead]
- zozbot234 3y agoSimilarities to birds? "Birds" aren't real, they literally are dinosaurs.