
Possible dinosaur DNA has been found - bookofjoe
https://www.scientificamerican.com/article/possible-dinosaur-dna-has-been-found/
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roywiggins
"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?

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tynpeddler
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 info on what stain they used to
identify the "DNA", the implications of this research are hard to figure out.

~~~
burtonator
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.

The main issue is that you'd have to find a LOT of DNA to build one complete
strand and you wouldn't have one strand from one specific animal.

... but you'd have a rough picture.

~~~
Robotbeat
What does half life of 500,000 years mean? Does that mean any given gene will,
on average, split every 500,000 years? Or become unusable in 500,000 years?

65 million years would mean 130 halvings. Basically nothing left, then.

...but this may depend on environmental conditions. this must depend on
average environmental temperature, right? Might dinosaur specimens in
Antarctic or Arctic regions have experienced significantly lower average
environmental temperatures? That could increase the half life significantly.

Maybe we'll find Cryolophosaurus DNA some day...

EDIT: the DNA degradation study specimen was in the south island of New
Zealand, which had an average burial temperature of 13C.

Antarctica along the coast has an average annual temperature of about -10C.
Further inland and at higher elevation, it's much colder and dryer. Both those
increase DNA stability. It's not crazy to me that you might have a factor of
100x greater stability for specimens found where the average temperature over
the last 65 million years was 20-40 degrees colder and also dryer.

EDIT AGAIN: Just to support what I said, it seems like a difference of average
burial temperature of just 2.5 degrees C doubles the half-life of DNA (and
this is multiplicative), so with a 20 degree difference in average burial
temperature, that would be 8 doublings of half-life length (factor of 256), so
instead of 500,000 years until the DNA was all broken up, you could have 128
million years.
[https://figshare.com/articles/_Predicted_DNA_half_life_for_v...](https://figshare.com/articles/_Predicted_DNA_half_life_for_varying_average_soil_temperature_for_each_fragment_type_/1420162)

~~~
gnramires
Not sure where his 500k years figure comes from. A cursory search gives 521
years:

[https://www.nature.com/news/dna-has-a-521-year-half-
life-1.1...](https://www.nature.com/news/dna-has-a-521-year-half-life-1.11555)

Chemical decay tends to follow Arrhenius equation:

[https://en.wikipedia.org/wiki/Arrhenius_equation#Equation](https://en.wikipedia.org/wiki/Arrhenius_equation#Equation)

so indeed a difference of maybe 40C should lead to a difference in half life
of about 20-30%. I think about 30 half lives (~10^-9 degradation factor)
should be the limit of recoverability, so perhaps 521x30 = 15k years in normal
conditions up to 521x30x1.25 = 20k years in low temperature.

Of course, other factors such as humidity could contribute as well to the
half-life, and reactivity is a lot more complicated than the Arrhenius model
in reality. But even then I would be surprised such a vast difference in
reactivity outside of true cryogenic conditions (maybe even shielding from
radiation?).

edit: your second edit is interesting :) is that curve polynomial or
exponential?

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Robotbeat
Looks exponential to me. After all, the Arrhenius equation (whose constants
seem different here than your earlier assumptions) is exponential.

~~~
gnramires
Oh yes, I definitely messed up my calculations. Half life is (inversely)
proportional to the reaction rate itself I guess (I were associating it with
the exponent, because half life is usually in the exponent), so the half life
itself would be proportional to exponential reciprocal of temperature
(e^(a/T)).

This means significant differences in HL for minor temperature variations
under e.g. Arrhenius model (consistent with your graph I think). To
extrapolate it some parameters need to be estimated though, which sounds
interesting, I'll get around to that later...

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syntaxing
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.

~~~
aphextron
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.

~~~
BrandonM
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 into the complex interaction between a mother and
her unborn child, including cytoplasm, mitochondrial RNA, etc. It's not like
an organism springs whole cloth from DNA alone.

~~~
dmurray
> Even with perfect DNA, I think we underestimate the role that social
> structure and ecological momentum play in even the simplest of creatures.

I don't think that's true. We raise animals without their parents all the
time, both on farms and in zoos. The animals we end up with are still
recognizably horses or rats or chimpanzees, with unique behavioural traits
that could be studied for years. Even if you lose the social structure of
mammoth society, you would still be bringing back something fascinating.

Animals that can be hatched from eggs have even less dependency on their
mothers, too.

~~~
mod
Was going to comment similarly.

I have 16 chicks in the brooder that have never been around a chicken. They
never will be around any but their 15 "siblings."

They're still acting like chickens, and they will continue throughout their
lifetimes.

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Taniwha
Yeah, but scientists are so preoccupied with whether or not they could make
dinosaurs without stopping to think if they should.

~~~
EmilioMartinez
By now they pretty much agreed that they should

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colinnordin
Assuming we had millions of 3D-scans of different kinds of animals and their
full DNA sequence. Wouldn't it be interesting to try to use generative ML
methods to generate a dinosaur DNA based on a 3D model?

~~~
andbberger
I suppose everything looks like a nail when you've got a few GPUs.

Besides, the sequence alone is not the full state. You have to also consider
expression and regulation and all that; epigenetics.

~~~
DavidSJ
I wonder:

Could you normally have two viable lineages, each with the same DNA, and each
with a different expression of that DNA which is stably conserved over many
generations, purely due to womb environment, etc.? In other words, if you
cloned a woolly mammoth using an elephant surrogate, might the great great
great great grandchildren of this clone still have some characteristics that
are due to having an elephant surrogate ancestor?

Or would there be a tendency to converge to a single stable expression due
entirely to genetics?

It‘s obvious that in principle the answer could go either way, but I’m not
sure whether that’s true in practice, with naturally occurring organisms and
naturally occurring DNA sequences. For the sake of this question, one is also
tempted to exclude post-natal “cultural” transmission, but it’s not clear that
can be easily distinguished.

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throwaway888abc
" Such potential tatters of ancient DNA are not exactly Jurassic Park–quality.
"

All right then.

~~~
buboard
Well we still have chicken

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Splendor
> Yet first, paleontologists need to confirm that these possible genetic
> traces are the real thing.

As is common with science articles, the headline doesn't quite match reality.

~~~
chc
The headline says possible dinosaur DNA has been found, and that quote agrees
that these samples are possibly dinosaur DNA. That seems to match.

~~~
echelon
Or bacterial DNA.

I think samples need to be isolated and sequenced before we know what we're
dealing with.

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pfarnsworth
Whatever happened to the finding 10+ years ago, where scientists found
jellified T-Rex bone marrow? It made a huge splash, and they claimed to be
able to see structures in the blood, etc, but I haven't heard anything since,
and I can't find any follow up research, or I don't know what to google for.

Has anyone seen any followups to this?

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darepublic
I'm sorry but I keep thinking of this:
[https://www.youtube.com/watch?v=h58lRIVHhGc](https://www.youtube.com/watch?v=h58lRIVHhGc)

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baybal2
Why would they wait, and no shove it into the sequencer if this is the case?

With modern sequencing technology, shouldn't they be able to detect strands of
base pairs much shorter than in the past?

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csvan
Young Earth Creationists are going to have a field day with this.

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29athrowaway
There's dinosaur DNA in every bird.

[http://tolweb.org/Dinosauria/14883](http://tolweb.org/Dinosauria/14883)

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gjsman-1000
Okay, quick and honest question: How does this support / not support the
theory of young earth creationism? For someone who believes that the earth is
6000 or so years old, and that humans and dinosaurs co-existed, and that DNA
doesn't last nearly _that long_, this seems like pretty definite proof of that
being possible. Counterpoint?

~~~
digitaltrees
That rests on the premise that dna doesn’t last that long. But maybe it does
and that premise is wrong. Alternatively radio carbon dating must be wrong and
with it large parts of chemistry. So I would weigh the strengths of both and
maybe scrutinize each premise for their respective scientific basis.

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elwell
> Using sophisticated techniques, they extract the preserved blood and bingo!
> Dino DNA!

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irrational
I have some eggs and chicken breasts in my fridge if anyone needs some
dinosaur DNA.

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rootsudo
I saw a movie about this once, can't remember the ending...

~~~
masonic
The chaos theory dude is discredited and ends up peddling apartments on TV
under pseudonyms.

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fortyseven
Dino-sour!

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parentheses
commence jurassic park 2020

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gok
Bingo!

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tunnuz
Life finds a way.

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zabeltech
Life will find a way

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0-_-0
The little kid in me got excited for a second seeing the headline

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rzimmerman
Bingo

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arthurcolle
They spared no expense.

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RedComet
I love how not only the time of existence but also its size and appearance are
presented as undisputable facts.

~~~
jstimpfle
Yeah and it's so wrong! Would they have checked the bible they'd agree that
the earth is 6000 years old.

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zabeltech
And flat obviously

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jstimpfle
It's not flat. When there was lack of food after the comet hit, dinosaurs
licked it so it became round.

