DNA has a 521-year half-life

[struggle4progress]

Genetic material can't be recovered from dinosaurs — but it lasts longer than thought.
Matt Kaplan
10 October 2012

... 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 ...

... 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 ºC. The findings are published today in Proceedings of the Royal Society B1.
Diminishing returns

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 ºC, 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 ...

http://www.nature.com/news/dna-has-a-521-year-half-life-1.11555

[Javaman]

1. And then there's this...

How long can DNA last? A million years, maybe more
http://www.msnbc.msn.com/id/49366487/ns/technology_and_science-science/

In "Jurassic Park," scientists extract 80-million-year-old dino DNA from the bellies of mosquitoes trapped in amber. Researchers may never be able to extract genetic material that old and bring a T. rex back to life, but a new study suggests DNA can survive in fossils longer than previously believed.

The oldest DNA samples ever recovered are from insects and plants in ice cores in Greenland up to 800,000 years old. But researchers had not been able to determine the oldest possible DNA they could get from the fossil record because DNA's rate of decay had remained a mystery.

Now scientists in Australia report they've been able to estimate this rate based on a comparison of DNA from 158 fossilized leg bones from three species of the moa, an extinct group of flightless birds that once lived in New Zealand. The bones date between 600 and 8,000 years old and importantly all come from the same region.

Temperatures, oxygenation and other environmental factors make it difficult to detect a basic rate of degradation, researcher Mike Bunce, from Murdoch University's Ancient DNA lab in Perth, explained in a statement.

more at link...

[Viva_La_Revolution]

2. this updates that (sadly)

"This confirms the widely held suspicion that claims of DNA from dinosaurs and ancient insects trapped in amber are incorrect," said Simon Ho, awesome dinosaur scientist at the University of Sydney Australia. And while these findings basically rule out ever cloning domesticated dinosaurs as the obvious transportation solution to solve the oil crisis, according to Ho, at least "we might be able to break the record for the oldest authentic DNA sequence, which currently stands at about half a million years."
http://www.escapistmagazine.com/news/view/120051-Science-Officially-Stomps-All-Hope-of-Dinosaur-Cloning