Two million year old DNA discovered in Greenland

Orange with media services, Posted on Sunday 11th December 2022 at 07:00

Various DNA fragments unearthed from Pleistocene deposits in Greenland are the oldest ever found. They are a million years older than the previous record, from DNA taken from a Siberian mammoth bone.

This is a significant discovery for paleontology: Two-million-year-old DNA has been discovered in Greenland, scientists announced this week, stating that it is the oldest ever recovered.

DNA can survive for 2 million years, twice as long as preexisting DNA.explains to AFP Mikkel Winter Pedersen, one of the lead authors of the study published in the scientific journal nature.

The various DNA fragments were identified in the sediments “from the northern part of Greenland, called Cape Copenhagen, and (are) from an environment we don’t see anywhere on Earth today,” he said.

They are well preserved because they are frozen and found in areas that have been little exploited, continues the lecturer at the University of Copenhagen.

“Rivers (carry) minerals and organic matter into the marine environment, where these terrestrial sediments were deposited. And then, at some point, about two million years ago, this land mass was lifted underwater and became part of northern Greenland,” he says.

Mastodons, reindeer and hares

Today Cape Copenhagen is considered a polar desert. Various types of sediments have been discovered there, including excellently preserved fossils of plants and insects. The researchers did not seek to prove the DNA of the items found, and there was very little information about the possible presence of animals.

The researchers’ work, which began in 2006, has made it possible to paint a picture of the region two million years ago. “We had this jungle environment with mastodons, reindeer, hares and a whole lot of different plant species. We found 102 different plant species,” says Mr. Winter Pedersen. According to him, the presence of mastodons is particularly notable because it had not been observed before until now in the North. Therefore, researchers are considering the ability of species to adapt because two million years ago, Greenland – “green land” in Danish – experienced temperatures 11 to 17 degrees warmer than today, but at these latitudes the sun neither sets in the summer months nor Set rise in winter.

“We don’t see this connection of species anywhere else on Earth today,” said the paleoecologist. This “makes you think about species resilience: How species can actually adapt to climate, with different types of climate, may be different than we previously thought.”

“We break the barrier of what we thought we could achieve”

Thanks to innovative technology, researchers have discovered that the 41 fragments studied are a million years older than the previous record of DNA taken from a Siberian mammoth bone. It was necessary to determine if the DNA was hidden in the clay and quartz and then it could be separated from the sediment for examination.

The method used “provides a fundamental understanding of why minerals or sediments are able to preserve DNA… It’s a Pandora’s box that we’re about to open,” explains Karina Sand, who directs the Geobiology group at the University of Copenhagen and was involved in the study.

For Mr. Winter Pedersen, with this discovery, “we’re breaking the barrier of what we thought we could achieve in terms of genetic studies.” “One million years was long thought to be the survival limit for DNA, but today we’re doubling that. And that’s clearly driving us looking for sites.”he adds. “There are many different sites around the world that contain geological deposits that go back this far. And even further back in time,” says the researcher.