Michael Crichton may not have been that far wide of the mark when he wrote Jurassic Park, as a sensational new paper in the journal National Science Review suggests that DNA may be able to persist for dozens of millions of years. This finding is sure to spark debate within the scientific community as it contradicts all previous evidence regarding the longevity of genetic material. If true, though, it could open up new possibilities for studying the biology of prehistoric organisms – but it certainly won't lead to any dinosaurs being resurrected.
Previous research has indicated that DNA can only remain stable for around a million years, leading to the assumption that genetic material has a sell-by date beyond which it degrades. Yet this latest study appears to blow that theory to smithereens by annoucing the discovery of DNA in a 75-million-year-old baby duck-billed dinosaur called a hypacrosaurus.
Housed at the Museum of the Rockies, the specimen caught the attention of researchers after an examination revealed the presence of some remarkably preserved cells within a section of fossilized cartilage tissue.
After isolating the cells, the study authors applied two DNA stains, which bind to fragments of DNA in order to show up any areas where genetic material is present. Both of the stains interacted with the hypacrosaur tissue in a pattern that is consistent with modern cells, indicating that some of the dinosaur’s DNA was indeed preserved within the sample.
"I couldn't believe it, my heart almost stopped beating," said study author Alida Bailleul in a statement. "These new exciting results add to growing evidence that cells and some of their biomolecules can persist in deep-time. They suggest DNA can preserve for tens of millions of years.”
While this finding certaily points to the possibility that DNA can survive for extremely long periods of time, the study authors also explain that this is only likely to occur under certain conditions. For instance, the fact that the bones in this particular sample had all become disconnected from each other suggests that that organism was not buried for some time after dying, which the researchers say probably aided the preservation of its DNA.
Additionally, they report that such ancient genetic material is only likely to be found in well-preserved cartilage cells, but not in bones. This is because cartilage is less porous than bone, and therefore lets in less water and microbes that could cause biodegradation.
In spite of this, researchers investigating other samples of preserved dinosaur cartilage have failed to detect any DNA, and it is thought that even if some could survive it probably wouldn't be intact.
If nothing else, this discovery re-opens the discussion on how long genetic material can persist for, and the study authors hope that their work will inspire researchers at museums around the world to seek out specimens with preserved cartilage tissues in search of more ancient DNA.