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Half-Life of DNA is 521 Years, Jurassic Park Impossible After All

Soulskill posted about 2 years ago | from the unless-you-have-a-time-machine dept.

Biotech 315

another random user writes with this quote from Nature News: "Few researchers have given credence to claims that samples of dinosaur DNA have survived to the present day, but no one knew just how long it would take for genetic material to fall apart. Now, a study of fossils found in New Zealand is laying the matter to rest — and putting paid to hopes of cloning a Tyrannosaurus rex (abstract). After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate. Determining that rate has been difficult because it is rare to find large sets of DNA-containing fossils with which to make meaningful comparisons. To make matters worse, variable environmental conditions such as temperature, degree of microbial attack and oxygenation alter the speed of the decay process. By comparing the specimens' ages and degrees of DNA degradation, the researchers calculated that DNA has a half-life of 521 years. That means that after 521 years, half of the bonds between nucleotides in the backbone of a sample would have broken; after another 521 years half of the remaining bonds would have gone; and so on."

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Someone forgot to tell these guys (3, Funny)

pkbarbiedoll (851110) | about 2 years ago | (#41610033)

Re:Someone forgot to tell these guys (4, Insightful)

dpilot (134227) | about 2 years ago | (#41610121)

That just says that they're going to inject the DNA - it doesn't say that they're going to get viable embryos out of it.

Re:Someone forgot to tell these guys (3, Informative)

sed quid in infernos (1167989) | about 2 years ago | (#41610167)

Why do they need to know? 10,000 years is roughly 20 half-life periods, so they should expect roughly 1-millionth of the DNA to remain.

Re:Someone forgot to tell these guys (5, Insightful)

busyqth (2566075) | about 2 years ago | (#41610411)

Why do they need to know? 10,000 years is roughly 20 half-life periods, so they should expect roughly 1-millionth of the DNA to remain.

Since the wooly mammoth genome is approximately 4.7 billion in 58 chromosomes, for an average of 81 million base pairs per chromosome, the DNA fragments would be, on average 81 base pairs long, which should be enough to figure out the original sequence after duplicating and matching. So a full reconstructed mammoth genome should be possible.

Re:Someone forgot to tell these guys (5, Interesting)

Groo Wanderer (180806) | about 2 years ago | (#41610731)

Heck, 81 base pairs would save you a lot of time chopping strands for PCR, you would already have the pieces. :)

Seriously though, given those numbers are for a single cell, how many do you have with a mammoth carcass? More than 1, in fact more than 1 million. If you can find a lab blender big enough to stuff a mammoth carcass in to, the rest should be trivial. I would also venture that after a while, the fact that a dinosaur bone didn't degrade to dust means that it is better preserved than your average thing stuffed in to the ground so the half life would, after a point, extend.

Given a few dinosaur samples, you could probably get enough to reassemble most of the genome. With some not all that complex math, you can compare it to a few key reptile sequences and likely get some strong hints or even direct sequences that are missing. Some things change a lot over time, others do not or can not.

And yes, I did do this in college. No, not on dinosaurs though, that would have been a bit more fun to talk about at the bars.

              -Charlie

Re:Someone forgot to tell these guys (1)

Anonymous Coward | about 2 years ago | (#41610465)

Dude, temperature-adjust your half-life period for -20C.

Re:Someone forgot to tell these guys (0)

Anonymous Coward | about 2 years ago | (#41610233)

Wah Wah Wee Wah! Borat Sagdiyev will be there to cover the whole revolutionary processes!

Re:Someone forgot to tell these guys (2)

mdfst13 (664665) | about 2 years ago | (#41610541)

There is a big difference between finding 10,000 year old mammoth DNA under near perfect conditions (the bodies froze quickly because it was already freezing and stayed frozen until they were found) and hoping to find 65 million year old Tyrannosaurus rex DNA under bad conditions (the processes that preserve fossilized bones are bad for DNA--too much heat and pressure). As cold weather animals, mammoths are ideal candidates for something like this. The dinosaurs required much warmer climates.

Re:Someone forgot to tell these guys (0)

Anonymous Coward | about 2 years ago | (#41610675)

1) freezing tissues is very different from leaving a bone at ordinary temperatures in groundwater
2) there are *no* frozen dinosaur remains from the Mesozoic. The oldest frozen remains of any kind of creature are "only" a couple hundred thousand years old.

But what about... (1, Funny)

Anonymous Coward | about 2 years ago | (#41610041)

A mosquito that bit a dinosaur encased in amber....

The hell with dinosarurs... (4, Funny)

cayenne8 (626475) | about 2 years ago | (#41610129)

...for God's sake, lets get samples and clone Keith Richards before its too late!?!?!?

Re:The hell with dinosarurs... (4, Funny)

NEDHead (1651195) | about 2 years ago | (#41610213)

Isn't he already older than 521 years? I suspect his DNA is suspect as it is.

Re:The hell with dinosarurs... (1)

Groo Wanderer (180806) | about 2 years ago | (#41610767)

Why? He is already so well preserved that we have plenty of time. Just keep him away from coconut trees and we are golden.

                    -Charlie

(Note: There is also a strong possibility that if we sequence Keith, we might get a few extraneous dinosaur chromosomes for free....)

Re:But what about... (0)

Anonymous Coward | about 2 years ago | (#41610253)

Why is the parent modded 'Funny' - that is the story behind how the scientists in Jurassic Park found dinosaur DNA...

Re:But what about... (4, Funny)

somersault (912633) | about 2 years ago | (#41610643)

Why is the parent modded 'Funny' - that is the story behind how the scientists in Jurassic Park found dinosaur DNA...

You just explained why it's funny.

Re:But what about... (2)

MRe_nl (306212) | about 2 years ago | (#41610267)

Well, that would be "One hell of a mosquito and an only slightly less impressive glob of amber", or "A very small dinosaur" obviously.

Re:But what about... (1)

Anonymous Coward | about 2 years ago | (#41610377)

This is a serious point. This summary mentions groundwater being ubiquitous, but groundwater doesn't penetrate amber. Neither do microorganisms.

Re:But what about... (0)

Anonymous Coward | about 2 years ago | (#41610497)

My guess is, the specimen has to be completely void of water and other things within it in order for the amber to work as a shield from the environment. You might get a longer half-life, but nowhere near the tens of millions of years required for us to make a new dinosaur from the old DNA... even with frog's to fill in the blanks. :)

Re:But what about... (0)

Anonymous Coward | about 2 years ago | (#41610565)

even with frog's to fill in the blanks

Frog's what?

Re:But what about... (5, Funny)

fragtag (2565329) | about 2 years ago | (#41610667)

He meant frogs not "frog's". Dino DNA is of course really large (Were talking a T-Rex afterall), so all they have to do is inject a whole frog directly in sequence. AAAATSAATTTTS(frog)AAA

Re:But what about... (3, Funny)

Anonymous Coward | about 2 years ago | (#41610429)

If the dinosaur is encased in amber, why do we need to wait for a mosquito? Why would we want to wait for a mosquito that can bite through amber... drill the thing then get the hell out of there.

Re:But what about... (3, Funny)

fahrbot-bot (874524) | about 2 years ago | (#41610525)

A mosquito that bit a dinosaur encased in amber....

Forget that. I'd like to see the tree that generated the sap to encase a dinosaur in amber. :-)

Mammoths? (3, Funny)

Culture20 (968837) | about 2 years ago | (#41610049)

Quick, what does this mean regarding mammoth burgers?

Re:Mammoths? (1)

snikulin (889460) | about 2 years ago | (#41610191)

Still a-good eatin' in remote Siberia and Alaska them places.
Tastes a bit like a roadkill, though.

As I'm not personally familiar with it; (1)

MRe_nl (306212) | about 2 years ago | (#41610451)

How does roadkill taste?
(And no, I don't know how mammoth tastes either).

Re:As I'm not personally familiar with it; (1)

K. S. Kyosuke (729550) | about 2 years ago | (#41610629)

How does roadkill taste?

It's a little bit earthy, with a slight aftertaste of rubber.

Ummmm (0)

Anonymous Coward | about 2 years ago | (#41610053)

"Putting paid"? WTF does that mean?

Re:Ummmm (4, Informative)

biodata (1981610) | about 2 years ago | (#41610149)

It is an English phrase meaning 'putting an end to' but using fewer words.

Re:Ummmm (2)

Raenex (947668) | about 2 years ago | (#41610393)

It is an English phrase

To be precise, it's "chiefly UK". Another alternative in idiomatic American English would be "putting to rest", which wins the Google fight against "putting paid to" by a large margin.

Re:Ummmm (5, Funny)

Anonymous Coward | about 2 years ago | (#41610293)

If you don't pay for your putting, you can't have any meat. How can you have any meat if you don't pay for your putting?

Re:Ummmm (0)

Anonymous Coward | about 2 years ago | (#41610687)

This made me LOL. Well played--thanks!

Re:Ummmm (1)

hippo (107522) | about 2 years ago | (#41610807)

When I read that I heard it in a shrieking Scottish accent. Well done.

So wait... (0)

Anonymous Coward | about 2 years ago | (#41610059)

You're telling me no manner of preservation could get us T-Rex dna? And we've got nearly complete mammoths, furry hides and all, in giant blocks of ice, but no DNA?

Something about this don't seem right. I want to speak with Dr. Alan Grant.

Re:So wait... (2)

Electricity Likes Me (1098643) | about 2 years ago | (#41610185)

That the actual research is about the rate of degradation of DNA in fossils, and not the viability of cloning from DNA recovered?

It should be obvious that the half-life doesn't imply ubiquitous degradation, and with 25-bases ensuring a very reliably unique match, it's conceivable you could recover enough to start a cloning project provided the initial reservoir was very large.

Re:So wait... (0)

Anonymous Coward | about 2 years ago | (#41610533)

It should be obvious that the half-life doesn't imply ubiquitous degradation

I'm no expert on this, but that's... not how this sounds.

Oh don't worry (1)

kiriath (2670145) | about 2 years ago | (#41610107)

Nobody has scientifically disproved time travel yet... we may yet get to see dinosaurs alive!

Re:Oh don't worry (1)

Anonymous Coward | about 2 years ago | (#41610347)

E=MC^2

Re:Oh don't worry (0)

Anonymous Coward | about 2 years ago | (#41610787)

Massively heavy on the theory there buddy.
Plus, that doesn't rule-out the thing either, and it especially doesn't rule-out tachyons. Never has, never will.

Not only that, the thing you meant to cite, Relativity, is old as high-hell.
Finally people are actually working on extending it realistically since, while it is a theory, a good chunk of it fits most observations so far, with a few exceptions towards large values where it begins spitting out ridiculous things like infinities.
And while we don't know for absolute sure yet, we are pretty sure infinities don't exist in the universe outside of theory and as a concept.

Tachyonic reactions DO exist. We just don't know their configuration, how they work behind the scenes and if they can be used for anything useful or large.

Re:Oh don't worry (2)

ColdWetDog (752185) | about 2 years ago | (#41610353)

All you need is C-span.

Although 'alive' is pushing it a bit.

Re:Oh don't worry (1)

Bill Hayden (649193) | about 2 years ago | (#41610637)

Those time travellers would return on a different timeline, so you'd still be out of luck. It would have to have already happened for you to be able to see it.

Cryogenics (3, Interesting)

SJHillman (1966756) | about 2 years ago | (#41610117)

Does this have any bearing on cryogenics or would that preserve the DNA?

Re:Cryogenics (5, Informative)

biodata (1981610) | about 2 years ago | (#41610189)

Cryogenics would pretty much stop most of the reactions that break the bonds, so half-life would be hugely increased, especially if material is properly dried first. Seeds can last for many decades and still grow if dried to 5% moisture content and frozen at -80. Not sure about animal embryos, but sperm and eggs also.

Re:Cryogenics (2)

Spottywot (1910658) | about 2 years ago | (#41610437)

FTA:

The calculations in the latest study were quite straightforward, but many questions remain. “I am very interested to see if these findings can be reproduced in very different environments such as permafrost and caves,” says Michael Knapp, a palaeogeneticist at the University of Otago in Dunedin, New Zealand. Moreover, the researchers found that age differences accounted for only 38.6% of the variation in DNA degradation between moa-bone samples. “Other factors that impact on DNA preservation are clearly at work,” says Bunce. “Storage following excavation, soil chemistry and even the time of year when the animal died are all likely contributing factors that will need looking into.”

Clearly the researchers are aware of the effects of different conditions and levels of preservation and are looking into it. Would be a bit worrying if they didn't.

Re:Cryogenics (0)

Anonymous Coward | about 2 years ago | (#41610711)

Before the last dinosaur died, he quickly built a maintenance-free solar-powered liquid nitrogen generator and dripped some of his blood into the dewar! Yikes! That was close! I thought we'd never fall to the bottom of the food chain again :)

Water? Microbes? The answer: Amber (0)

Anonymous Coward | about 2 years ago | (#41610133)

Yes, water and stuff is bad for DNA, m'kay? Didn't they know that is why you use blood of dinosaurs that is enclosed in amber? D'uh.

Just do not fix the holes was DNA from frogs. That's going to end badly...

Frog DNA? (0)

Anonymous Coward | about 2 years ago | (#41610135)

Jurassic Park had it figured out. They patched the destroyed parts with frogs DNA which fucked up everything

Re:Frog DNA? (1)

gapagos (1264716) | about 2 years ago | (#41610679)

I'm surprised that they didn't call it "Frogassic Park" instead of Jurassic Park.

No water, no air, no bonds broken? (5, Insightful)

Doofus (43075) | about 2 years ago | (#41610151)

So in amber, or some other similar impermeable substance, the chemical reactions requiring water or air might well be prevented or dramatically slowed, thus the degradation of DNA might be substantially slower than the 521 years described in the summary.

Not necessarily the end of the Jurassic Park idea.

Re:No water, no air, no bonds broken? (4, Interesting)

Sparticus789 (2625955) | about 2 years ago | (#41610257)

Also worth mentioning, what about the tar pits? If an animal is surrounded by tar and sealed in, what happens to the DNA degradation?

Re:No water, no air, no bonds broken? (1)

rwv (1636355) | about 2 years ago | (#41610475)

But the hand-wave explanation used in Jurassic Park was DNA from dinosaurs extracted from blood stored in the stomach of mosquito's that had been preserved in amber. So why it remains an interesting question to ask regarding the effect of tar pits... TFS seems to glaze over the effect of mosquito/amber preservation that would specifically address whether Jurassic Park is possible. A similar article about why mosquito/amber preservation is bunk would also be relevant... because I assume we've never found amber entombed mosquito's from the Jurassic Period.

Re:No water, no air, no bonds broken? (0)

Anonymous Coward | about 2 years ago | (#41610553)

The degraded DNA is spliced in from frogs, so a bunch of degradation is OK!

Re:No water, no air, no bonds broken? (2)

Maximum Prophet (716608) | about 2 years ago | (#41610611)

"there were several reports, including the one in 1992, that claimed that DNA fragments had been recovered from insects that had died between 25 and 125 million years ago. These reports caused considerable excitement, but despite intensive efforts no other researchers, including the team at The Natural History Museum, have been able to repeat and verify these results. As a result of these findings, most scientists now agree that DNA doesn't survive in fossilized insects in amber."

http://www.nhm.ac.uk/resources-rx/files/12feat_dna_in_amber-3009.pdf [nhm.ac.uk]

Short answer: It was plausible, but now is considered debunked. Unless a dino got frozen for 150 mega-years, there's no Jurassic to be.

Re:No water, no air, no bonds broken? (1)

K. S. Kyosuke (729550) | about 2 years ago | (#41610799)

Not necessarily the end of the Jurassic Park idea.

From the beginning, it was obvious that Jurassic Park is to genetic engineering as Star Trek is to astronautics: good entertainment, a captivating story, an even better sound track, but nothing even remotely related to reality.

I prefer to transfer my DNA (1)

badford (874035) | about 2 years ago | (#41610161)

the old fashioned way.

Ba-dum-cha!

Frog DNA (0)

Anonymous Coward | about 2 years ago | (#41610165)

Just use frog dna to fill in the holes...nothing could possibli go wrong.

Question... (5, Insightful)

Savage-Rabbit (308260) | about 2 years ago | (#41610169)

If the half-life of DNA is 521 years how are scientists able to sequence 30.000 year old Neanderthal DNA? Presumably this applies to regular DNA, did Svante Pääbo and his team sequence mtDNA?

Re:Question... (0)

Anonymous Coward | about 2 years ago | (#41610317)

From TFA:

The team predicts that even in a bone at an ideal preservation temperature of 5 C, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.

So 30,000 years doesn't seem to be beyond recoverable, as long as you get enough material from a body kept under roughly ideal conditions.

Re:Question... (1)

Savage-Rabbit (308260) | about 2 years ago | (#41610705)

From TFA:

The team predicts that even in a bone at an ideal preservation temperature of 5 C, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.

So 30,000 years doesn't seem to be beyond recoverable, as long as you get enough material from a body kept under roughly ideal conditions.

So you are saying that the DNA is fragmented but it can still be 'stitched' together even If the DNA degrades. How do you re-assemble the DNA of an archaic hominid accurately when it had DNA that was different from ours? I suppose you could use the DNA of modern humans as a clue but if that is the case (and I'm not saying it is), what about animals that are extinct and have no close genetic relative today like, say, a terror-bird. What I mean is that with Neanderthal DNA being sequencable we could theoretically some day clone a Neanderthal does that mean that 'Pleistocene park' is theoretically doable, that we could some day theoretically possibly clone any animal from the Pleistocene period as long as we have the genetic data?

Re:Question... (0)

Anonymous Coward | about 2 years ago | (#41610325)

Huh, you're right (intuition told me that it'd still be fairly close at that many half-lives) 30,000 years is 60 half lives or 10^-18. There are somewhere around 10^14 cells in the body (if you mashed a whole neanderthal and ran him/her through your machine). I don't know where the extra four orders of magnitude come from, but I suspect it's well preserved samples due to environment (I imagine the halflife increases rather drastically if your sample is encased in a glacier) combined with errors averaging out somehow.

Re:Question... (1)

ColdWetDog (752185) | about 2 years ago | (#41610463)

It has taken folks decades to get the technology to sequence such DNA. It's very degraded. IIRC, they rely on multiple overlaps of small fragments and the technology has been pushing that fragment size down over the years. I'm sure you could look it up. To tired at the moment.

Re:Question... (5, Informative)

MaXintosh (159753) | about 2 years ago | (#41610607)

Scientist here (you can tell by my hat, and the fact that something like 90% of my comments on /. start with "I'm a biologist"). First, the DNA we get is from better preserved remains, which kicks the half life back further (It's in TFA, but not mentioned in the summary). There's still a 'deadline' around 7 MYA, where (allegedly) all the bonds would have pretty much been broken at that point - Frozen remains supposedly have a halflife around 158 kya. It's that dang phosphate backbone that's too willing to run off and go have reactions with any trallop of a molecule that wanders on by.

This means even in the relatively recent past, the amount of DNA we're looking at is pretty dang tiny. Part of the reason ancient DNA is so dang tricky is because the much of what you sequence is not actually what you're interested in - doubly so when you're sequencing something closely related to humans. For example, did some spot sequencing of ancient/historic polar bear remains, and had to toss out a chunk of the data we got back, as it was soil bacteria(/fungi/pollen) contamination. How do we know which is which? We had good scaffolds to align our bear sequences back up again, though not everyone is as fortunate as us.

In addition to being rare, what is left is fairly short. You can imagine if you start putting breaks in at random, your average length is going to start declining rapidly, and then level out at some small value that takes quite a while to get smaller. It'll get there, and given geologic time scales, a lot of what we want is that far back, but it'll take a while.

Finally, what isn't mentioned in this summary is that there was massive variance in the estimates of half-life. Supposedly only 40% of the variance in halflife was explained by age. Preservation, inter-lab differences, and good old fashioned luck probably contribute considerably to variance in half-life.

There are other factors too, but they're boring, and I should probably get work done instead of dragging out this reply.

(And to answer your latter question, Neanderthals have been sequenced whole genome, not just mtDNA).

Building a dinosaur from a chicken (2)

John Bokma (834313) | about 2 years ago | (#41610197)

An option (?) still open:

Jack Horner: Building a dinosaur from a chicken | Video on TED.com [ted.com] - Renowned paleontologist Jack Horner has spent his career trying to reconstruct a dinosaur. He's found fossils with extraordinarily well-preserved blood vessels and soft tissues, but never intact DNA. So, in a new approach, he's taking living descendants of the dinosaur (chickens) and genetically engineering them to reactivate ancestral traits — including teeth, tails, and even hands — to make a "Chickenosaurus".

Re:Building a dinosaur from a chicken (1)

Man On Pink Corner (1089867) | about 2 years ago | (#41610523)

Exactly. Much of the "lost" DNA is still very much available, in the form of the dinosaurs' descendants.

Not only that, but any sample of nontrivial size will contain plenty of redundant DNA strands. This "half-life" business can be dealt with through instrumentation and data analysis, if not through chemistry or biology alone.

Re:Building a dinosaur from a chicken (1)

PortHaven (242123) | about 2 years ago | (#41610755)

I thought Mosanto already invented the chickensaurus. And that's why chicken breasts today are the size of yesteryear's turkey breasts?

But Jurassic Park wasn't bsaed off fossil DNA (2)

91degrees (207121) | about 2 years ago | (#41610201)

It was based off DNA from blood from an insect trapped in amber.

Now, the enzyme degradation will no doubt be an issue, as well as the rareness of mosquitoes preserved in amber, but that's another matter.

Re:But Jurassic Park wasn't bsaed off fossil DNA (1)

Mike Buddha (10734) | about 2 years ago | (#41610507)

An article on this at The Register pointed out that even in amber, the DNA had very little chance of surviving 1.5M years, let alone the 62M years that would have been required for Jurrassic Park to have happened.

If its left exposed... sure. (1)

powerlinekid (442532) | about 2 years ago | (#41610203)

What if it is sealed in a way that microbes, oxygen, etc can not interfere with it? Say amber, a tar swamp, a deep freeze?

No I did not read the article nor do I have any knowledge on the subject beyond that leaving a steak on a counter in 100 degree heat has a very different outcome than putting it in a sealed bag in a freezer.

Re:If its left exposed... sure. (0)

Anonymous Coward | about 2 years ago | (#41610297)

Eggzactly! - If it's cold enough, or isolated enough, or both, the time for it to degrade enough to be completely no longer possible to get any useful information from it, given the most advanced analysis technology available, has got to be far, far longer than this makes it sound.

Re:If its left exposed... sure. (1)

powerlinekid (442532) | about 2 years ago | (#41610459)

The article actually addresses this and DNA is capable of lasting 1.5 to 6 million years.

Typical crap Slashdot summary pandering to the Anti-Cloning lobby.

Difficult is not impossible. (1)

Anonymous Coward | about 2 years ago | (#41610215)

So, it's been about 65,000,000 years since the dinosaurs became extinct. Which means each piece of DNA has degraded by half 130,000 times. 1/2^130,000 is about 1 e -39000. Which is a lot of zeros. Each recovered strand conveys an infinitismal amount of information about the original. If you had only one cell, you could barely guess at the original DNA sequence.

But that doesn't make it impossible. Because all the cells of a given organism are genetically identical (or close enough) when the animal died. With enough cells, you can theoretically "average out" the (presumed random) noise until the underlying "signal" of the original DNA sequence emerges. It will take a LOT of samples, but organisms have a LOT of cells.

Uh, what? (3, Insightful)

Daetrin (576516) | about 2 years ago | (#41610223)

Wikipedia seems to have a page all about doing what this article says is impossible: http://en.wikipedia.org/wiki/Ancient_DNA [wikipedia.org]

It claims there are multiple cases of Neanderthal DNA being sequenced, and a couple quick google searches seem to indicate there are many other similar situations where DNA was recovered.

So i'm wondering, did this study perhaps prove that if nothing is done to preserve the DNA after death then... surprise! The DNA isn't preserved?

Practical limit,~1.5 million years (4, Informative)

slew (2918) | about 2 years ago | (#41610249)

The 521 year half-life is if the DNA is exposed to water in typical situations, ITFA (in the article) they give an estimate for the best case situation...

The team predicts that even in a bone at an ideal preservation temperature of 5 C, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.

“This confirms the widely held suspicion that claims of DNA from dinosaurs and ancient insects trapped in amber are incorrect,” says Simon Ho, a computational evolutionary biologist at the University of Sydney in Australia. However, although 6.8 million years is nowhere near the age of a dinosaur bone — which would be at least 65 million years old — “We might be able to break the record for the oldest authentic DNA sequence, which currently stands at about half a million years,” says Ho.

As other posters point out, the famous mammoth recreated from DNA was from about 10,000 years ago, much less than the 1.5 million year practical limit estimated by this research team.

Re:Practical limit,~1.5 million years (1)

Anonymous Coward | about 2 years ago | (#41610427)

I'd really like to know their original concept for asserting entropic change in a static environment. Inside a bone, absent an appreciable energy source, any microorganisms would be killed off in far less than 6.8 million years. What continues the decay of genetic bonds? These bonds presumably do not consume energy by their very existence, so what is the environmental pressure causing them to break? Wouldn't the default assumption be that, absent an external influence, the bonds would remain intact indefinitely? How did they come to this conclusion?

Fill in the gaps? (1)

llZENll (545605) | about 2 years ago | (#41610259)

If ape and human DNA are 5-10% different, then perhaps dinosaur and some current reptile DNA are very similar as well, since now you have 90% of the DNA already, you have to find much less, and if you have billions of samples of DNA, perhaps they could be reconstructed. I would think that by the time we are able to do such a thing we won't be far from being able to create our own dinosaur from scratch.

Re:Fill in the gaps? (1)

Havokmon (89874) | about 2 years ago | (#41610455)

Yeah, right. Then lesbian dinosaurs start mating and we're spending the rest of our lives avoiding Pterosaur poo.

Re:Fill in the gaps? (0)

Anonymous Coward | about 2 years ago | (#41610579)

Dinosaurs are birds, not reptiles.

...of a sample... (1)

Relic of the Future (118669) | about 2 years ago | (#41610269)

"after 521 years, half of the bonds between nucleotides in the backbone of a sample would have broken"

Okay, but there were how many billion copies of the sample when the creature died? If there were two, after 521 years I still have (on average) at least one copy of 3/4 of the data, extending the half-life to (check my math here) 737 years. With 15 billion copies or so, the half-life gets up to, hey!, about 65 million years, and there are trillions of cells (and so trillions of copies of DNA) in a human-sized body.

Not impossible (2)

michaelmalak (91262) | about 2 years ago | (#41610283)

It's not impossible. You just show the computer a photo of a dinosaur, let it start from the DNA of a Komodo Dragon, and let it try different "what if" changes to the DNA, simulating the growth of the each resulting organism. Could even happen within the lifetime of Randall Munroe.

Not impossible? (1)

Anonymous Coward | about 2 years ago | (#41610363)

> ... a photo of a dinosaur ...

I think you have a bit of a problem in step 1

Re:Not impossible (4, Funny)

ColdWetDog (752185) | about 2 years ago | (#41610573)

OK. I just showed my computer a picture of a Komodo Dragon. It just is sitting there, doing nothing.

Now what am I supposed to do?

Frog DNA (1)

areusche (1297613) | about 2 years ago | (#41610351)

Just get more of it. Problem solved.

Transport Phenomenon? (0)

Anonymous Coward | about 2 years ago | (#41610357)

With the transport of water into and out of a bone - how old are those bones now?

So what did MarySchweitzer find? (4, Interesting)

Zinho (17895) | about 2 years ago | (#41610365)

Is this why we haven't heard much from Mary Schwietzer [discovermagazine.com] lately? Six years ago she isolated soft tissue remnants from inside a T-rex femur.

More recently, Charlotte Oskam (Biologist at Murdoch University in Australia) identified DNA in fossilized egg shells [metro.co.uk] .

We've always known that DNA was unlikely to survive the passage of aeons, this just puts a number to it. Specific conditions could still allow better than typical preservation, and so I dislike making an absolute statement that we'll never find it. Hopefully those who are still looking for the elusive ancient DNA will take this study as a way to focus their search rather than have their funding cut.

News for nerds (3, Funny)

Hadlock (143607) | about 2 years ago | (#41610403)

But we're going to explain to you how half-lives work anyways.

Re:News for nerds (1)

Mike Buddha (10734) | about 2 years ago | (#41610567)

If there's one thing you should have learned from Slashdot it's that simply being a nerd doesn't make one less stupid, less ignorant, or less technically inclined.

Re:News for nerds (1)

Hadlock (143607) | about 2 years ago | (#41610609)

At the same time, it also shouldn't make you less capable of googling a term you don't understand.

Hmm (4, Funny)

kiriath (2670145) | about 2 years ago | (#41610405)

I wonder if 521 years is how long we'll be waiting for Half Life 3?

Re:Hmm (1)

PortHaven (242123) | about 2 years ago | (#41610781)

Nope, that's the release date for Duke Nukem 4D!

Ladies and gentlemen.. (4, Funny)

jd2112 (1535857) | about 2 years ago | (#41610417)

Welcome to Dodo Park.

Sorry, it just doesn't have the same ring to it.

There is still hope. (2)

TsuruchiBrian (2731979) | about 2 years ago | (#41610431)

This doesn't fundamentally change anything. Even if half your DNA is destroyed every 521 years, large multicellular organisms have trillions of cells containing copies of their DNA. You don't need to find a single complete correct set. That is already hard enough to do in living organisms. You can assemble a mostly complete set from many incomplete sets. Recovering data from a harddrive with corrupted data is very hard. Recovering the data from a trillion copies of the same data that was corrupted in different random ways is much much easier. As long as every section of data survived in some of the copies, it can be reassembled. Even if there is not enough DNA in a single organism to do this, the differences between the DNA of individuals of the same species is very small. This is what makes sexual reproduction possible. Maybe we can't clone a T-Rex, but if we find enough genetically similar DNA from multiple T-Rexs, we can theoretically make a T-Rex "offspring" of all of them. We don't really care about cloning an specific individual T-Rex anyway. A genetic T-Rex that never existed, but does now, is perfectly acceptable. Maybe there isn't enough T-Rex DNA in the whole world to make a coherent set of DNA. That's possible. All I am saying is that we still have some more good tricks up our sleeve, and we shouldn't give up yet. We will certainly clone some kind of Pleistocene organism like a mammoth as an earlier step anyway. No reason to decide what are limits are so early in the game.

Jurassic Park still possible (3, Interesting)

captaindomon (870655) | about 2 years ago | (#41610435)

Even given the half life, we may be able to resurrect dinosaurs. Remember that we are talking about information that is encoded, with billions of copies hanging around. Given we can find enough samples, even if they are all missing different portions, we may be able to piece together the complete sequence by combining the portions of each sample that survived. Throw in extremely cold temperatures like the article talks about, and some Jurassic-park style replacement of certain portions from modern animals, and it is still very possible. Maybe not today, but in 100 years I can see it being very possible.

Re:Jurassic Park still possible (0)

Anonymous Coward | about 2 years ago | (#41610605)

Just like bit torrent.

Re:Jurassic Park still possible (1)

Maximum Prophet (716608) | about 2 years ago | (#41610735)

Create something that looks like a Dinosaur, walks and generally does things we think a dino should do: -> Very Likely

Reproduce a T-Rex exactly like it was: -> Not so Likely.

250M-year-old bacteria were revived in 1999... (2)

jeffb (2.718) (1189693) | about 2 years ago | (#41610469)

...or so researchers claimed. I know there was some skepticism around their claim, but was it ever refuted?

But, can error correction algorithms compensate? (0)

Anonymous Coward | about 2 years ago | (#41610511)

Since each cell's DNA is essentially a duplicate of all others, is it possible to compensate over this short half life by using millions of cells from the same creature with error correction in order to reconstruct the original sequence correctly in its entirety?

"Impossible After All" (3, Insightful)

jlv (5619) | about 2 years ago | (#41610547)

One of the best ways to make it happen is to declare it's "impossible". It gives people something to strive for.

What about possible cells from t. Rex fossil? (1)

smooth wombat (796938) | about 2 years ago | (#41610645)

For those who don't know, in 2005 it was announced a paleontologist had inadvertently found what appeared to be remnants of blood and or related items inside a t. Rex fossil. Three reference stories:

Story 1 [msn.com]

Storey 2 [smithsonianmag.com]

Story 3 [pbs.org]

IF, and that's a big if, what this paleontologist has found is un-fossilized bits of t. Rex, would it be possible to see if any bits of DNA remain? As she states in the third article, she is not equipped to look for DNA and so can't do it.

Not doubting what the research has found, but if this stuff is something that is real, would it hurt to look and prove the exception to the rule?

Maybe just look harder... (0)

Anonymous Coward | about 2 years ago | (#41610757)

Yet this was possible...
---------
Amplification and sequencing of DNA from a 120-135-million-year-old weevil.
http://www.ncbi.nlm.nih.gov/pubmed/8505978

Ignorance is bliss. (0)

Anonymous Coward | about 2 years ago | (#41610761)

This ignores the ability to do statistical analysis of the breakdown products, and the ability to build the DNA from the analysis. It may be impossible to use the DNA, but that does not mean it is impossible to rebuild it.

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