Scientists find 2m-yr-old DNA in Greenland

Scientists in Greenland announced Wednesday they had found DNA dating back two million years -- the oldest ever extracted -- in sediment from the Ice Age, opening a new chapter in paleogenetics.

"We are breaking the barrier of what we thought we could reach in terms of genetic studies," said Mikkel Winther Pedersen, co-author of a new study published in science journal Nature.

"It was long thought that one million years was the boundary of DNA survival, but now we are twice as old" as that, Pedersen told AFP.

They found the DNA fragments in sediment from the northernmost part of Greenland known as Kap Copenhagen, said the University of Copenhagen lecturer.

The fragments "come from an environment that we do not see anywhere on Earth today," he added. Frozen in a remote unpopulated area, the DNA had been very well preserved.

New technology enabled the scientists to determine that the 41 fragments were more than a million years older than the oldest known DNA, from a Siberian mammoth.

They had to first determine whether there was DNA hidden in the clay and quartz, then see whether it could be removed from the sediment to examine it.

The method used "provides a fundamental understanding of why minerals, or sediments, can preserve DNA", said Karina Sand, who heads the geobiology team at the University of Copenhagen and who took part in the study.

"It's a Pandora's box we're just about to open up", she added.

The "rivers running through the environment transported minerals and organic material into the marine environment and this was where these terrestrial sediments were deposited", said Winther Pedersen.

Then, at some point around two million years ago, "this land mass beneath the water was raised up and became a part of North Greenland", he explained.

Today, Kap Copenhagen is an Arctic desert, where different types of deposits, including plant and insect fossils preserved in excellent condition, have already been discovered.