A new study is finally laying to rest the debate over whether DNA from the age of the dinosaurs could survive to the present day.

Scientists at Murdoch University led a study which shows the rate of DNA degradation and calculates that all bonds in a DNA strand preserved at the ideal temperature of minus five degrees centigrade would be completely destroyed in bone after approximately 6.8 million years.

This figure is incompatible with the idea of finding intact DNA in an 80 million year old dinosaur remnant, as was famously alluded to in the Steven Spielberg film Jurassic Park, but is much older than the currently accepted record of 450,000 to 800,000-year-old DNA from Greenlandic ice cores.

Dr Mike Bunce and Dr Morten Allentoft from Murdoch Universitys Ancient DNA lab came to their conclusions after studying 158 fossilised leg bones belonging to three species of the moa, an extinct group of birds that once roamed New Zealand.

It has been agonisingly difficult to estimate the rate of DNA decay before now because finding a large set of DNA-containing fossils with which to make meaningful comparisons are exceedingly rare, said Dr Bunce.

Environmental conditions like temperature, degree of microbial attack and oxygenation, can affect the DNA decay process and make it hard to detect a basic rate of degradation.

The moa bones however have allowed us to study the comparative DNA degradation because they come from different ages from a region where they have all experienced the same environmental conditions.

The fossil bone specimens were carbon dated as being between 600 and 8000 years old and looking at the varying degrees of DNA degradation in each specimen, the team were able to calculate a DNA half-life of 521 years. The half-life is the amount of time taken for an amount of DNA to reach 50 per cent of the starting amount.

The scientists found that the estimated decay rate in the specimens was almost 400 times slower than predicted from simulation experiments carried out in the lab.

Based on these calculations and other investigations, the team were able to make their predictions of DNA survival deeper into time.

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Mystery of DNA decay unravelled

ST. LOUIS Rodney Lincoln has spent half his life in prison and knows he will spend the rest there, too, unless a sealed Federal Express container en route to Lorton, Va., can unlock his cell.

Inside: A swab of red stain from the front edge of a kitchen sink. A piece of aluminum door frame with a bloody fingerprint. A steak knife and butcher knife, both with blood. A broom. And a piece of tissue paper left near a doorway where the killer fled.

Those are among the physical evidence stored for decades from the gruesome murder of JoAnn Tate and attack on her two young daughters at their St. Louis apartment on April 27, 1982.

Now, with the state's blessing, the evidence will be tested by Bode Technology, in the suburbs of Washington. It specializes in DNA comparisons, science not available at the time of the crime.

The Midwest Innocence Project is paying for the testing, believing the results will not only free Lincoln whose case they've been fighting for years but also point to a particular man it suspects of being the real killer.

Tate's family, however, hopes the tests will put a final stamp on Lincoln's conviction and provide closure.

A GRUESOME CRIME

Police who responded on that spring morning to Tate's apartment on Farrar Street encountered a gory scene.

Tate, 35, was facedown in a pool of blood, fatally stabbed in the chest and sexually assaulted with a broom. The killer delivered 10 stab wounds to Tate's daughter, Melissa, 7, and sliced the throat of Renee, 4.

Melissa feebly told relatives who found them, "Bill did it."

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DNA testing keeps convicted killer's hopes alive

Palaeogeneticist Morten Allentoft used the bones of extinct moa birds to calculate the half-life of DNA.

M. Mhl

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.

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.

But palaeogeneticists led by Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, examined 158 DNA-containing leg bones belonging to three species of extinct giant birds called moa. The bones, which were between 600 and 8,000 years old, had been recovered from three sites within 5 kilometres of each other, with nearly identical preservation conditions including a temperature of 13.1 C. The findings are published today in Proceedings of the Royal Society B1.

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.

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.

The calculations in the latest study were quite straightforward, but many questions remain.

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DNA has a 521-year half-life

We are used to radioactive substances having a half-life, but DNA? Now a study of bones from extinct birds suggests the double helix too has a measurable half-life and that we have underestimated its ability to survive in the fossil record.

"DNA degrades at a certain rate, and it therefore makes sense to talk about a half-life," says Morten Allentoft at Copenhagen University, Denmark, who together with Mike Bunce at Murdoch University in Perth, Australia, and colleagues, extracted DNA from the leg bones of 158 extinct flightless birds called moas.

Part of the reason a DNA half-life has been so elusive is that it is hard to find a large enough cache of samples that have been exposed to similar conditions. The moa bones were all between 600 and 8000 years old, and came from a 5-kilometre-wide area of New Zealand's South Island, key factors for helping identify a regular pattern of decay.

With an estimated burial temperature of 13 C, the DNA's half-life was 521 years almost 400 times longer than expected from lab experiments at similar temperatures, says Allentoft.

The oldest DNA to date belongs to insects and plants and was found in 450,000 to 800,000-year-old ice. Under subzero conditions, Allentoft and Bunce estimate that DNA's half-life can be up to 158,000 years, meaning the last remnants would disappear around the 6.8-million-year mark. Allentoft does say that is an optimistic assessment, and doesn't imply that samples of DNA large enough to measure could be extracted from such old bones.

Eva-Maria Geigl at the Jacques Monod institute in Paris, France, is still to be convinced by the half-life claims, which she says rest on statistically weak evidence. She points out, for example, that the correlation relies heavily on the moa bones older than 6000 years when fewer than 10 of the 158 bones are this ancient.

"Old fossils are rare and hence there will be less data in this part of the analysis," says Bunce. "There is nothing we can do about it other than present what we have at hand and clearly, the signal is present. The correlation is highly significant."

If DNA decays in a predictable way, can we calculate the chances of finding it at key sites? Ever since the Indonesian island of Flores yielded remains of the "hobbit", Homo floresiensis in 2004, speculation has been rife that some specimens might contain DNA that would help pin down its position in the human family tree. This notion has been spurred by evidence that the hobbits may have survived until as recently as 18,000 years ago.

Unfortunately, Bunce thinks the new calculations will be difficult to apply to specific sites. "A host of other factors come into play," he says, including the season the organism died. In fact, although the moa bones in the analysis had been buried in a similar environment, the age of the specimens could account for only about 40 per cent of the variation in DNA preservation in other words, the half-life signal is noisy.

Alan Cooper, director of the Australian Centre for Ancient DNA at the University of Adelaide, South Australia, agrees. "The rotting process after death is very seasonal and context dependent, and has a major impact on DNA survival."

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DNA's half-life identified using fossil bones

DNA from two home-invasion robbery suspects who allegedly stole a truck and then got into a fatal hit-and-run crash will be pivotal evidence in their trial, which started Tuesday, the prosecutor said.

Curtis Travis, 35, and Stephen Stowers, 24, both of Fresno, are on trial for murder, robbery and hit-and-run in the death of Heliodoro Anthony Ruvalcaba, 50, of Fresno, who was killed in January 2011.

Ruvalcaba was on his way home from his janitorial job when he was struck by a truck that Travis and Stowers allegedly stole minutes earlier.

The pair had been at a friend's apartment at 4111 N. Blythe Ave. about 1 a.m. on Jan. 5, 2011.

A short time later, they forced their way into another apartment at the complex, taking a laptop computer, two cellphones, $10 and keys to the resident's pickup, police reports state.

David Ruiz testified Tuesday that he was asleep in the apartment with his wife and two children when Travis and Stowers entered by breaking a window.

After hearing the noise, he went into his living room to investigate and was ordered by the two men to hand over his keys, cash, laptop computer and cellphones. Ruiz said he did so because he feared for the lives of his wife and daughters.

Ruiz described the men as light-skinned and dark-skinned, and he identified Travis as the man who made most of the demands. He could not positively identify Stowers. Travis is white and Stowers is black.

The pair left in Ruiz's 1994 Chevrolet Silverado, running two red lights before speeding about 60 mph eastbound on Ashlan Avenue near Highway 99, police said.

Travis, reportedly the driver, ran red lights at Ashlan and the Highway 99 offramp and hit Ruvalcaba's northbound 1998 Ford Taurus, killing him, police said.

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DNA links Fresno robbery suspects to fatal crash

Reconstructing dinosaurs from ancient DNA has been dealt a blow with a new study finding genetic material can only last 1 million years.

An international team of researchers reached the finding after analysing DNA extracted from bones of the extinct New Zealand moa.

They found that while short fragments of DNA could possibly survive up to 1 million years, sequences of 30 base pairs or more would only have a half-life of around 158,000 years under certain conditions.

Lead author Dr Morten Allentoft from Murdoch University's Ancient DNA lab in Perth says their results contradict earlier studies which claimed to have extracted DNA fragments several hundred base pairs long from dinosaur bones and preserved insects, claims which underpinned the storyline of the 1993 movieJurassic Park.

"What we show here with the decay rate of DNA is that this is never going to be possible," Dr Allentoft said.

"It may be that you can have extremely short fragments of DNA, only a few base pairs that persist for maybe a million years, maybe even longer."

Dr Allentoft says the earlier findings may have been due to contamination with human DNA.

Rate of decay

The latest study, published in the Proceedings of the Royal Society B, also establishes a DNA decay rate which could help identify specimens likely to yield useful genetic material.

It might also one day enable DNA to be used to date bones and teeth or even be used for forensic investigation of human remains.

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DNA dating study kills off Jurassic Park

STONY BROOK, NY--(Marketwire - Oct 9, 2012) - Applied DNA Sciences, Inc. ( OTCBB : APDN ), (Twitter: @APDN), a provider of DNA-based anti-counterfeiting technology and product authentication solutions, announced today that 3SI Security Systems is expanding its use of APDN's SigNature DNA evidence marking product into 3SI smoke and dye cash protection systems used across Europe. First orders, to the banking sector, are already being processed.

3SI Security Systems is a world leader in cash protection systems designed to recover stolen cash and high-value assets, apprehend criminals and deter crime.

The smoke and dye system, called Thinpac, is already in use in over 130,000 locations worldwide, with great success at deterring crime. 3SI called the addition of SigNature DNA marking to the Thinpac "a unique and leading edge security feature which we are happy to be able to offer to our customers." The company points out that "SigNature-DNA-tagged items can be identified unequivocally with a marker unique to a specific Thinpac, and hence unique to a particular crime. Any item, cash or person that comes in contact with the smoke will be marked by the SigNature DNA."

Police forces across Europe are becoming more familiar with the use of unique SigNature DNA markers in cash-protection systems, placing them in a much better position to catch and convict criminals. SigNature DNA provides police with a welcome additional investigative tool, which often reduces the amount of time it takes the police to undertake such investigations.

James Hayward, Chairman and CEO of Applied DNA Sciences, said, "Our SigNature DNA product is now used in many countries across Europe and is increasingly popular with police. One of our best examples of how the police make excellent use of our DNA to catch criminals is in the United Kingdom where 48 criminals have already been convicted and jailed for over 242 years, providing a great deterrent that has helped to significantly reduce the number of Cash in Transit robberies."

SigNature DNA is used to protect approximately 26% of cash movements in the United Kingdom.

Protection of bank tellers adds to APDN's portfolio of cash protection products. 3SI already uses APDN SigNature DNA marks to protect nearly 5,000 ATMs, using a DNA liquid which is placed in ink tanks that are fitted inside individual ATM cassettes. The cassette activates when triggered, marking all the cash inside the ATM and the criminals.

David Stanks, CEO of 3SI Corporation noted, "We have proven that we can significantly extend the value of our solutions by including the SigNature DNA products. This is a logical continuation of our strategy to deter crime and protect people."

About Applied DNA Sciences

APDN is a provider of botanical-DNA based security and authentication solutions that can help protect products, brands and intellectual property of companies, governments and consumers from theft, counterfeiting, fraud and diversion. SigNature DNA and smartDNA, our principal anti-counterfeiting and product authentication solutions that essentially cannot be copied, provide a forensic chain of evidence and can be used to prosecute perpetrators.

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Applied DNA Sciences and 3SI Use DNA to Protect Teller Stations

Update: A forensic expert in the Corryn Rayney murder investigation was asked to check whether a specific third person had left behind hair in Mrs Rayney's car or at the alleged crime scene, statements have revealed.

Statements from forensic scientist Rosalyn Treliving were among those released to the media today.

In her statements, the scientist says she had been given hairs found in Mrs Rayney's car and outside her Como home - the alleged crime scene - to see whether they matched her husband Lloyd Rayney or a third person whose name is blacked out of the statements for legal reasons.

Mr Rayney has pleaded not guilty to wilful murder and denies any involvement in the death of his wife who was last seen alive at a dance class that evening.

In her statements, Ms Treliving said that not all the hairs contained roots and of those that did no DNA was recoverable apart from partial profiles corresponded with Mrs Rayney's profile and therefore could have come from her.

She concluded the findings could not assist in determining whether Mr Rayney or the third person were involved in Mrs Rayney's death.

She also examined a handkerchief found in Mrs Rayney's grave, locating possible saliva but not blood. The handkerchief did not yield DNA.

Ms Treliving stated that tests were also conducted on DNA extracts from hair on Mrs Rayney's clothes, DNA from a tree branch at her gravesite and DNA from a hair in her body bag.

She said DNA samples from the gravesite branch and from on hair on her clothes could not be reliably said to have come from Mrs Rayney, her husband or the other suspect. but they did contain components that could not have come from the trio.

A single DNA component from hair on Mrs Rayney's clothes that corresponded with both Mrs Rayney and her husband's profiles bore little significance while a single DNA component from the body bag hair and which matched the un-named suspect was also of little significance becasue it was in one of every five people.

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Rayney investigators seek 'third person' DNA

HOUSTON (KTRK) -- DNA testing has led to a man being charged in the 2003 rape of an elderly woman.

According to court documents, the victim, who was 77 at the time of the alleged incident, told police she was raped on August 8, 2003 in the dining room of her apartment on N. Braeswood. The woman says a man grabbed her from behind and dragged her to her bedroom as she screamed for help. Then she says the man punched her and threw her to the floor.

Court documents state the suspect stole her coin jar and piggy bank, then tied her hands together and sexually assaulted her. The woman says he took her purse too.

The woman said she did not see the suspect's face because the room was dark and she suffers from degenerative eye disease. She got a rape kit on the same day.

Then on September 21 of this year, DPS crime lab identified a DNA profile match with Wesley Bernard Gordon.

Gordon, 40, is charged with aggravated sexual assault of elderly person. He is not in custody.

Court records show Gordon has prior convictions for theft in 1990 and burglary of a motor vehicle in 1991.

(Copyright 2012 KTRK-TV/DT. All Rights Reserved.)

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DNA testing leads to charges in elderly woman's rape in 2003

A few months ago someone asked me (via email) which populations I would love to get typed (genetically that is). There is one population which did not come to mind at the time: the Sumerians. Why? Because these are arguably the first historic nation. The first self-conscious ethnic group which operated by the rules which we define as the fundamentals of literate civilization. Strangely, they are an ethno-linguistic isolate. My own assumption until lately has been that this is not too surprising, in that prior to the rise of expansive civilizations (Sargon of Akkad) there was much more linguistic and ethnic diversity than we currently see around us. Or, was evident even in the early Iron Age. In other words, the ancient Fertile Crescent may have resembled the highlands of Papua, with Hurrians, Akkadians, Gutians, Elamites, Sumerians, etc., all speaking mutually unintelligible dialects which diverged very far back in the mists of antiquity.

I am no longer quite so sure about this model. That is largely due to the possibility that there was a great deal of demographic change between the Mesolithic and the Bronze Age, with successive waves of layering and replacement. My rough model is that a few groups of farmers may have expanded to swallow up thousands of hunter-gatherer groups. These homogeneous farmer societies eventually would diversify, because they were not united by the institutional forces which cemented later imperial regimes, in particular, literate elites which had a sense of consciousness which extended deep into the past because of written records.Therefore, the diversification would presumably have been similar to what we see with Romance languages, or Indo-Aryan, branching out from an common root language which replaced many competitors rapidly. Without writing and large scale polities the divergence would be more rapid, and there would be many more tips on the phylogenetic tree.

The Sumerians, and their neighbors the Elamites, as well as groups like the Hatti and Hurrians & Urartian, pose problems for this thesis. None of these groups seem to be Indo-European or Semitic, the two dominant language families of Near East by ~1,000 B.C. You have in the ancient Near East then a situation where the light of history reveals before us not the diversification of Indo-European and Semitic speaking farmers, but rather a host of unique and disparate peoples, all simultaneously lurching toward literate civilization, one after another.

Something just does not add up in my models. Genetics will not solve the puzzle, but it may help in elucidating relationships. The origins of the Sumerians are murky, but many scholars have suggested that they may have arrived from the south (the oldest city, Eridu, is in the south). Others have suggested that the Sumerians descended from the mountains of the northeast. Though I presume that the people Arabia have changed a great deal since antiquity, it would be interesting if it was found that the Sumerians resembled the Qatari (at least the Eurasian component) more than they did the modern Assyrians.

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Ancient DNA and Sumerians | Gene Expression