Discovery of the oldest DNA in the world, dating back 2 million years

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 that they have discovered the oldest DNA extract ever recorded. Two million years old, it was unearthed from Ice Age sediments in Greenland, which opens a new chapter for paleogenetics.

“DNA can survive for 2 million years, which is twice as old as previously found DNA,” says 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 “gives a basic understanding of why minerals or sediments can preserve DNA…it’s a Pandora’s box we’re about to open,” says Karina Sand, who heads the geobiology group at the University of Copenhagen and participated in the study.

Fragments are so well preserved because they are frozen and found in small exploited surfaces that, for Mikkel Winther Pedersen, with this discovery we “break the barrier of what we thought we could achieve in relation to genetic studies”.

“One million years has long been considered the limit of DNA survival, but today we are twice that. And of course it pushes us to look for sites, he adds.

The “green earth” and its unique environment

The researchers’ work had begun in 2006, so they were able to establish a “portrait” of the region two million years ago. But beyond the DNA fragments, the presence of a mastodon alone is particularly noteworthy because it had never before been found this far north.

Identified in sediments, the various DNA fragments “come from the northernmost part of Greenland, called Cape Copenhagen, and (are) from an environment that we don’t see anywhere on Earth today,” said Mikkel Winther Pederson.

In fact, 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 determine the DNA of the elements found, and there was very little information about the possible presence of animals.

This unique environment therefore makes scientists think about the adaptability of the different species that were rubbing shoulders at the 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 in the winter.

Finding Siberian mammoths ‘makes you think about the plasticity of species: how species are actually able to adapt to a climate, to different types of climates, may be different than we thought before,’ Mikkel Winther Pederson concluded.

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