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Possible dinosaur DNA has been found

scientificamerican.com

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Re: Possible dinosaur DNA has been found

#91

Post by haihaibye »

daemonk wrote: post #52
burtonator wrote: post #49

Earlier quoted context omitted.

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…

That's pretty much how modern genome assemblies work. We currently do not have a reliable or accurate way of sequencing DNA longer than ~200 bases. So we fragment the DNA into small pieces, sequence them and then put it all back together. It's not a completely solved problem as there are features of genomes that can make this process difficult or complicated (repetitive regions, highly heterozygous organisms, etc). E…

Illumina sequencers (highest throughput per $) have a (paired end total) read length of 300 but we can sequence much longer with other tech.

Ie Pacbio - 10-15kb

Sanger sequencing, used for the human genome project 20 years ago is over 500 bases

Re: Possible dinosaur DNA has been found

#92

Post by mkl »

TuringNYC wrote: post #73
varenc wrote: post #40

Earlier quoted context omitted.

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)?

It seems to depend mostly on temperature and moisture: dry, cold, and unchanging are best. We have good DNA from Deniovans because it was recovered from bones and teeth that sat buried in a cave in Siberia for 50k years.

Being in amber might protect from moisture, but I think the temperature and temperature swings would still likely destroy it within thousands of years.

Re: Possible dinosaur DNA has been found

#93

Post by kijin »

a_t48 wrote: post #79
kuprel wrote: post #77

Earlier quoted context omitted.

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. :)

The Australian army has had enough difficulty dealing with emus already. Dinosaurs would absolutely wipe them out.

On a more serious note, are egg sizes proportional to the size of the animal, or does the curve flatten after a certain size? I can't imagine an adult T-Rex dropping eggs that are 90cm across, for example, without either breaking them or making the shell impractically thick.

Re: Possible dinosaur DNA has been found

#94

Post by nerfhammer »

kijin wrote: post #93
a_t48 wrote: post #79

Earlier quoted context omitted.

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

The Australian army has had enough difficulty dealing with emus already. Dinosaurs would absolutely wipe them out. On a more serious note, are egg sizes proportional to the size of the animal, or does the curve flatten after a certain size? I can't imagine an adult T-Rex dropping eggs that are 90cm across, for example, without either breaking them or making the shell impractically thick.

there is a maximum viable egg size, which is about as big as an ostrich egg, due to the square-cube law. Eggs need to be semi-breathable, but as volume increases cubically, surface area increases only quadratically, but surface area is needed for breathability.

So huge dinosaurs had eggs that weren't much bigger than ostrich eggs, containing relatively tiny offspring. Maybe they would have been very cute. Or not, since baby birds often aren't that cute.

Since eggs had to be small, many dinosaurs utilized r-selection, like sea turtles for example, producing large numbers of eggs that only a tiny percent of which would survive to adulthood. This may also be why there were such ferociously efficient superpredator dinosaurs, because there were large numbers of relatively helpless juvenile dinosaurs scampering around to be preyed upon.

Re: Possible dinosaur DNA has been found

#95

Post by 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?

Re: Possible dinosaur DNA has been found

#96

Post by digitaltrees »

gjsman-1000 wrote: post #95

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?

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.

Re: Possible dinosaur DNA has been found

#97

Post by throwaway2048 »

gjsman-1000 wrote: post #95

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?

Young earth creationism isn't predicated on any kind of consistent or logical position.

Its advocates almost without exception, do not give a shit about the facts, and you aren't going to sway them with another few pebbles added to the absolute mountain of evidence that their position is flawed.

Debating them like their position has merit and is reasonable is a hopeless waste of time, and is in fact exactly what they want because it puts their position on level footing with the scientific consensus.

Re: Possible dinosaur DNA has been found

#98

Post by djmips »

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.

Whenever this comes up I wonder why no one mentions any associated symbiotic bacteria that might also be necessary for a dinosaur to live. Is it accepted that they could live without any additional microorganisms from the same time period?

Re: Possible dinosaur DNA has been found

#99

Post by 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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