DNA can survive 2 million years, which is twice as old as previously found DNAexplains AFP Mikkel Winther Pedersen, one of the lead authors of the study published in the journal Nature (New window) (in English).

Identified in sediments from which various DNA fragments originate from the northernmost part of Greenland, called Cape Copenhagen, and [sont] from an environment we see nowhere on earth todayhe said.

They are so well preserved because they were frozen and found in little-used surfaces, the lecturer at the University of Copenhagen continues.

” The rivers [ont transporté] Minerals and organic matter in the marine environment where these terrestrial sediments were deposited. And then, sometime around 2 million years ago, this underwater landmass was raised and became part of North Greenland. »

Cape Copenhagen is now an arctic desert. Various types of deposits have been discovered there, including excellently preserved plant and insect fossils. The researchers had not attempted to determine the DNA of the found items, and there was very little information about the possible presence of animals.

The researchers’ work, begun in 2006, has made it possible to draw a portrait of the region 2 million years ago.

” We had this forest environment with giants, reindeer and rabbits and with many different types of plants. We found 102 different plant taxa. »

According to him, the occurrence of mastodons is particularly noteworthy as it had never before been noted so far north.

Researchers are therefore reflecting on the adaptability of species, because 2 million years ago Greenland – “green earth” in Danish – experienced temperatures that were 11 to 19 degrees Celsius higher than today, but at these latitudes the sun does not set in the summer months or in the winter rise.

We don’t see this community of species anywhere else on earth today., emphasized the paleoecologist. That makes you think about the plasticity of species: how species can actually adapt to one climate, to different climate types, may be different than we previously thought.

Thanks to innovative technology, the researchers discovered that the 41 fragments examined predate the previous record of DNA taken from a Siberian mammoth bone by a million years.

It had to be determined whether DNA was buried in the clay and quartz, and whether it was possible to extract it from the sediment in order to examine it.

The method used provides a basic understanding of why minerals or sediments can conserve DNA…it’s a Pandora’s box that we’re about to opensays Karina Sand, who heads the geobiology group at the University of Copenhagen and was involved in the study.

For Mr. Winther Pedersen, with this discovery, We’re breaking the barrier of what we thought we could achieve in terms of genetic studies.

” It was long thought that a million years was the limit of DNA survival, but today we’re double that. And that, of course, drives us to look for websites. »

There are several different locations around the world that have geological deposits that go back this far. And even further in timegreets the researcher.