Scientists have announced that they have extracted the oldest DNA to date, two million years old. This major discovery was made from Ice Age sediments in Greenland, opening a new chapter for paleogenetics.
A discovery that will revolutionize genetics. Scientists have announced in the scientific journal Nature, having discovered the oldest DNA extract ever identified. Two million years old, it was unearthed from Ice Age sediments in Greenland, opening a new chapter for paleogenetics.
“DNA can survive for 2 million years, which is twice as old as previously found DNA,” said Mikkel Winther Pedersen, one of the study’s lead authors.
A technological feat
No less than 41 fragments have been studied by scientists. Thanks to innovative technology, they were able to take these fragments, twice as old as previous records, from a Siberian mammoth bone.
The method used “provides a fundamental understanding of why minerals or sediments can preserve DNA…it’s a Pandora’s box we’re regarding to open,” says Karina Sand, who leads the geobiology group at the University of Copenhagen and participated in the study.
Fragments so well preserved because frozen and found in little exploited surfaces, that for Mikkel Winther Pedersen, with this discovery, “we break the barrier of what we thought we might achieve in terms of genetic studies”.
“A million years was long thought to be the limit of DNA survival, but today we are double that. And obviously, that pushes us to look for sites,” he adds.
The “green earth” and its unique environment
The work of the scientists had begun in 2006, they were thus able to establish a “portrait” of the region two million years ago. However, in addition to the DNA fragments, the presence of a mastodon alone is particularly notable because it had never before been found so far north.
Identified in sediments, the different DNA fragments come “from the northernmost part of the Greenlandcalled Cape Copenhagen, and (are) from an environment that we don’t see anywhere on Earth today,” said Mikkel Winther Pederson.
Indeed, Cape Copenhagen is today an arctic desert. Different types of deposits, including excellently preserved fossils of plants and insects, had already been discovered there. However, the researchers had not sought to establish the DNA of the elements found, and very little information existed on the possible presence of animals.
This unique environment therefore makes scientists think regarding the adaptability of the different species that rubbed shoulders at that time. Greenland, Danish for ‘green earth’, had temperatures 11 to 17°C warmer than today, but at these latitudes the sun does not set in the summer months or rise during Winter.
Finding Siberian mammoths there ‘makes you think regarding species plasticity: How species are actually able to adapt to one climate, to different types of climates, might be different than we thought before,” concluded Mikkel Winther Pederson.
