According to a paper posted in National Science Review, scientists propose that DNA may actually be able to last for dozens of millions of years – a finding that’s sure to spark as much controversy as excitement in the scientific community.
If it’s true, new avenues for studying the biology of prehistoric organisms could surely be available (though no one is saying we could or should resurrect dinosaurs anytime soon).
The claims made in the paper are definitely controversial; previous research indicated that DNA only remains stable for around a million years. The discovery of DNA inside a 75-million-year-old baby duck-billed dinosaur called a Hypacrosaurus, though, could upend everything we previously “knew” about ancient DNA.
The specimen, housed at the Museum of the Rockies, revealed some remarkably preserved cells within a section of fossilized cartilage tissue during a routine examination. Researchers isolated the cells, the applied two DNA strains, which bind to fragments of DNA and highlight areas where genetic materials are present.
In the Hypacrosaurus tissue, both of the DNA strains interacted in a pattern consistent with modern cells. That indicates that at least some of the dinosaur’s DNA was preserved, says study author Alida Bailleul,
“I couldn’t believe it, my heart almost stopped beating.
These new exciting results add to the 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.”
Of course, only certain conditions will lend themselves to preserving DNA for longer periods of time.
The bones in this particular sample had all become disconnected from each other, suggesting that the organism didn’t end up buried until after it had started to decompose – a set of circumstances the researchers say probably led to the DNA’s preservation.
The report also posits that ancient genetic material is only expected to be found in well-preserved cartilage cells, not bones. Cartilage is less porous than bone, so it lets in less water and microbes that break down the material.