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Possible dinosaur DNA has been found

scientificamerican.com

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Re: Possible dinosaur DNA has been found

#71

Post by Baeocystin »

brobinson wrote: post #47
Baeocystin wrote: post #35

Earlier quoted context omitted.

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 the…

Right, but even a small amount of water (and presumably, ice) is amazing at absorbing radiation. Wouldn't something buried in a few meters of ice or more be effectively insulated from radiation?

DNA isn't isotope free.

Like hyperbovine mentioned, there are actually other effects that come in to play far sooner, but radiation puts (an additional) hard cap on things, and is easy to napkin-math.

Re: Possible dinosaur DNA has been found

#73

Post by TuringNYC »

varenc wrote: post #40
empath75 wrote: post #30

Earlier quoted context omitted.

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.

Curious what the half life would be for dinosaur blood within Amber (per the book)?

Re: Possible dinosaur DNA has been found

#74

Post by gorgoiler »

burtonator wrote: post #49
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…

There was a paper not long ago saying that the DNA half life is about 500k years or so and that most of the DNA would be degraded. The issue I had with this is why can't we reassemble chunks of DNA like we can with a puzzle. I'm certain specialized algorithms exist within DNA analysis for this reason. This isn't my field and there are already algorithms that exist on the top of my head that could solve this issue. Th…

> reassemble like a puzzle

That’s a good enough analogy for modern DNA sequencing.

The code of DNA is an image trapped in an opaque box. Instead of being able to image the complete picture of an organism’s DNA, you take thousands of identical images in opaque boxes, smash the boxes and their contents into tiny pieces to get bits of image out, then line up the now exposed fragments to see the original image.

It is the realignment that is the computationally expensive part of the process.

Re: Possible dinosaur DNA has been found

#76

Post by gus_massa »

londons_explore wrote: post #64
neilwilson wrote: post #21

Earlier quoted context omitted.

It would die near instantly anyway. Very likely modern bacteria and viruses would overwhelm the creature's immune systems.

The same argument could apply when you take plants or animals from one continent to another when those continents haven't been connected for tens of millions of years. Yet somehow camels or kangaroos seem to have no trouble living in each others environments. In fact, you see a bit of the reverse - Banana skin rapidly decomposes in tropical forests where bananas grow, but take one to frigid Norway and drop a banana s…

The part of the banana skin looks like a very nice experiment if you have a webacam and five years available.

Re: Possible dinosaur DNA has been found

#77

Post by kuprel »

koeng wrote: post #41
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.

Possible? Yes. Practical? Not for 2-3 decades when DNA synthesis capacity gets good enough to synthesize full animal genomes. In terms of raw synthesis power, we do have the ability to synthesize billions of base pairs, but you're going to need other infrastructure around it. Also, immune problems I don't think would be a huge issue, the adaptive immune system has been around for a while.

If we could synthesize the dinosaur DNA, would a chicken be able to hatch a dinosaur egg if we injected it in the right place?

Re: Possible dinosaur DNA has been found

#78

Post by bosswipe »

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…

What they found is structures that looked like cells under a microscope: https://academic.oup.com/view-large/figure/200008005/nwz206f... Section C shows cell-like structures and D shows the hypothesised DNA-like structure. They compare with a modern Emu's microstructures in section G.

They also applied a stain to the fossil and compared it to a stained emu bone here https://academic.oup.com/view-large/figure/200008014/nwz206f...

Re: Possible dinosaur DNA has been found

#79

Post by a_t48 »

kuprel wrote: post #77
koeng wrote: post #41

Earlier quoted context omitted.

Possible? Yes. Practical? Not for 2-3 decades when DNA synthesis capacity gets good enough to synthesize full animal genomes. In terms of raw synthesis power, we do have the ability to synthesize billions of base pairs, but you're going to need other infrastructure around it. Also, immune problems I don't think would be a huge issue, the adaptive immune system has been around for a while.

If we could synthesize the dinosaur DNA, would a chicken be able to hatch a dinosaur egg if we injected it in the right place?

I'd go for something larger like an emu, personally. :)

Re: Possible dinosaur DNA has been found

#80

Post by [deleted] »

credit_guy wrote: post #46
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.

> DNA has a half life of ~500 years DNA is not a radioactive material. It decays, but there's no absolute law like the radioactive decay, where the half life is the same for every microgram of the same substance everywhere in the world. The average half-life may be 500 years, but there can be situations where the DNA is exceptionally well preserved due to local circumstances. As a simple analogy: the average half lif…

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