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Possible dinosaur DNA has been found

scientificamerican.com

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Re: Possible dinosaur DNA has been found

#31

Post by [deleted] »

roywiggins wrote: post #27
tynpeddler wrote: post #15

Earlier quoted context omitted.

Homology studies. A DNA strand 17 bp long is pretty distinct. If a strand that long or longer was found, we would gain a lot of information about the evolutionary history of dinosaurs that we could never get from fossils. However, the article isn't clear about what they found. It says DNA, then it says there may not be a recoverable sequence. In that case nucleic acids would be a better term than DNA. Without more in…

"broken down components" reads like loose nucleic acids to me, rather than actual DNA fragments

[deleted]

Re: Possible dinosaur DNA has been found

#32

Post by crimsonalucard »

tynpeddler wrote: post #15
roywiggins wrote: post #10

"At best, their biological makers seem to be degraded remnants of genes that cannot be read—broken-down components rather than intact parts of a sequence." So... what good does that do?

Homology studies. A DNA strand 17 bp long is pretty distinct. If a strand that long or longer was found, we would gain a lot of information about the evolutionary history of dinosaurs that we could never get from fossils. However, the article isn't clear about what they found. It says DNA, then it says there may not be a recoverable sequence. In that case nucleic acids would be a better term than DNA. Without more in…

I think by what "good does that do?" he means like what's the point if you can't use it to create dinosaur clones Jurassic Park style.

I literally clicked on the link because that was the only thing on my mind. Not joking.

Re: Possible dinosaur DNA has been found

#34

Post by varenc »

roywiggins wrote: post #10

"At best, their biological makers seem to be degraded remnants of genes that cannot be read—broken-down components rather than intact parts of a sequence." So... what good does that do?

The article is a bit inconsistent on its claims. But in the paper the authors seem to say that intact DNA sequences could exist:

"... to this date, the possible preservation of original proteins and DNA in deep time has not been convincingly eliminated with data."

"Our data support the hypothesis that calcified cartilage is preserved at the molecular level in this Mesozoic material, and suggest that remnants of once-living chondrocytes, including their DNA, may preserve for millions of years."

https://academic.oup.com/nsr/article/doi/10.1093/nsr/nwz206/

Re: Possible dinosaur DNA has been found

#35

Post by Baeocystin »

zabeltech wrote: post #14
aphextron wrote: post #8

Earlier quoted context omitted.

It's a completely impossible fantasy. DNA has a half life of ~500 years. Mammoths only died out around 10,000 years ago, which is why it's conceivable that one could be brought back, but all dinosaur DNA has been destroyed for millions of years.

What if the DNA was frozen?

At these time scales, background radiation is the fundamental killer, and it is omnipresent in the environment.

Using numbers taken from http://news.mit.edu/1994/safe-0105 for napkin-math:

Average background dose/year: 500 millirem

LD50 instantaneous exposure: 450000 millirem

LD100 instantaneous exposure: 600000 millirem

Radiation exposure of our dinoDNA sample: 65 million * 500 = 32.5 billion millirem.

Obviously there's a lot more to it than simple dose adding, but this gives you an idea of just what deep-time DNA recovery is up against.

Re: Possible dinosaur DNA has been found

#36

Post by phiresky »

aphextron wrote: post #8
syntaxing wrote: post #3

This is a naive question...but let's just say we do have the DNA, is Jurrasic park possible with today's technology?! I remember reading that someone was trying to inseminate an elephant with mammoth sperm a couple years ago but failed. Not sure if it was because the sample was super old or it just doesn't work.

It's a completely impossible fantasy. DNA has a half life of ~500 years. Mammoths only died out around 10,000 years ago, which is why it's conceivable that one could be brought back, but all dinosaur DNA has been destroyed for millions of years.

> DNA has a half life of ~500 years

but:

Researchers in 2016 measured chloroplast DNA in marine sediment cores, and found diatom DNA dating back to 1.4 million years.[62] This DNA had a half-life significantly longer than previous research, of up to 15,000 years. Kirkpatrick's team also found that DNA only decayed along a half-life rate until about 100 thousand years, at which point it followed a slower, power-law decay rate.

https://en.wikipedia.org/wiki/Ancient_DNA#Non-human_aDNA

Re: Possible dinosaur DNA has been found

#37

Post by grecy »

aphextron wrote: post #8
syntaxing wrote: post #3

This is a naive question...but let's just say we do have the DNA, is Jurrasic park possible with today's technology?! I remember reading that someone was trying to inseminate an elephant with mammoth sperm a couple years ago but failed. Not sure if it was because the sample was super old or it just doesn't work.

It's a completely impossible fantasy. DNA has a half life of ~500 years. Mammoths only died out around 10,000 years ago, which is why it's conceivable that one could be brought back, but all dinosaur DNA has been destroyed for millions of years.

Alright, let's just pretend the DNA was somehow snap frozen or preserved to make it still useable.

With today's technology could we create a creature from long ago with nothing more than it's DNA?

Re: Possible dinosaur DNA has been found

#39

Post by dumbfoundded »

BrandonM wrote: post #28
aphextron wrote: post #8

Earlier quoted context omitted.

It's a completely impossible fantasy. DNA has a half life of ~500 years. Mammoths only died out around 10,000 years ago, which is why it's conceivable that one could be brought back, but all dinosaur DNA has been destroyed for millions of years.

Bringing back mammoths based only on DNA seems to me to be akin to bringing back a New Yorker based only on DNA, thousands of years after NYC no longer exists. Even with perfect DNA, I think we underestimate the role that social structure and ecological momentum play in even the simplest of creatures. I think humans are the rule and not the exception when it comes to learning after birth. And that's not even getting…

So the culture issue you raise definitely presents some unrecoverable aspect, but as for the biology, there's certainly a path.

We have animals now that are closely enough related to extinct animals that we could conceivably bring them back through incremental genetic modifications.

For example, if we wanted to bring back Direwolves, we could edit the DNA of a gray wolf maximally such that it can still be fertile and be born by a non-edited gray wolf. This would give you a wolf closer to a Direwolf and then you could repeat this process using each previous generation as the carrying mother for the genetically modified embryo.

Re: Possible dinosaur DNA has been found

#40

Post by varenc »

empath75 wrote: post #30
TuringNYC wrote: post #26

Earlier quoted context omitted.

>> DNA has a half life of ~500 years. Could you describe half life here? So suppose the strands are now small snippets. If you find enough, couldnt you overlap common parts and eventually re-construct the full length?

It means half of the dna is destroyed every 500 years. After 65,000,000 years, you have 1/(2^130,000)th of the original DNA left, which is to say, none at all.

DNA half-life isn't an immutable property of the material like radioactive half-life is. The environment has an effect. The DNA in cryogenically preserved tissue should have a much longer half life.
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