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Half-Life of DNA is 521 Years, Jurassic Park Impossible After All
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."
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.
The living have better things to do than to continue hating the dead.
...for God's sake, lets get samples and clone Keith Richards before its too late!?!?!?
Light travels faster than sound. This is why some people appear bright until you hear them speak.........
It is an English phrase meaning 'putting an end to' but using fewer words.
Korma: Good
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.
If the Government becomes a lawbreaker, it breeds contempt for law;
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?
Only to idiots, are orders laws.
-- Henning von Tresckow
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.
Korma: Good
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.
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?
Is this why we haven't heard much from Mary Schwietzer 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.
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.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
I wonder if 521 years is how long we'll be waiting for Half Life 3?
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.
Welcome to Dodo Park.
Sorry, it just doesn't have the same ring to it.
Any insufficiently advanced magic is indistinguishable from technology.
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?
Faster! Faster! Faster would be better!
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.
which is totally what she said
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
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
Something must be wrong with the 521 years. 65 million years / 521 years = 124.760 half lifes.
That means only 1 / (2^124.760) = 1 / (3,1787695069134767997232294562089e+37556) of the original DNA should be available for analysis today. Those guys would be lucky to find a single base pair that has not decayed. Hardly a sufficient basis to make a quantitative analysis ;-)
C - the footgun of programming languages
The half-life of unusual British phrases in the US is less than 18 years.
Even more importantly, this ignores a previous published article on "DNA Sequence from Cretaceous Period Bone Fragments" -- Science 266 (5188) 1229-1232, here is a PDF of the article in Science. Either 80 mya (Cretaceous) is horribly wrong, the 521 year half-live of DNA is horribly wrong, Woodruff, et al were horrible deceived (or frauds) or some combination of these.
You would hope evidence would be the deciding factor, but scientists are human too, and the interpretation of evidence is often more important than the actual evidence -- it is very hard to upset to prevailing opinion (as it should be when the opinion is well founded)
the assumptions in the 521 year half life number is that we are above freezing temperatures. so mammoth DNA has a different experience
there are arguments to make that frozen water would lengthen the half life (frozen water is not as chemically active) or shorten it (ice crystals shredding the dna physically rather than chemically)
i'm not knowledgeable enough to guess if the frozen effect would save the DNA better or shred it even worse, but i think it is a valid to say that the half life would be a lot different if you are dealing with a corpse that was frozen at death and stayed that way in permafrost the entire thousands of years time before getting to a modern biotech lab
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Yes, but back then we called them 'Safety goggles'. They had a precursor to a holographic UI called 'scratches'. It worked much the same in practice.
-Charlie
521 years should be enough for anybody.
Hey now there's no need to exaggerate, Gabe said HL3 will be done when it's done.
"Mind, as manifested by the capacity to make choices, is to some extent present in every electron." -Freeman Dyson