Now a completely new picture is emerging of what Greenland looked like two million years ago.

Fragments of ancient genetic material (dna) that have been preserved in frozen sedimentary layers can now tell about a landscape that is very different from today's ice-covered stone deserts.

Birches and hares

Two million years ago, the global average temperature was 11 to 19 degrees higher than today.

The DNA fragments show that there was a mixed forest here consisting of poplars, birches and tujas, which is a cypress-like coniferous tree.

Rodents, hares, reindeer and geese roamed here, but there are also traces of marine animals that thrive in much warmer water than it is in Greenland today.

Eske Willerslev is an evolutionary geneticist at the University of Copenhagen and leads the research group that made the discovery.

He got quite a surprise when they analyzed the old genome:

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We found DNA from a mastodon that no one has ever thought existed in Greenland before, he says.

Extinct 10,000 years ago

Mastodons are a distant relative of the mammoth and became extinct when the ice age came to an end 10,000 years ago.

The fragments of genetic material from the mastodon and the other animals and plants have been preserved because they bind to different minerals in the soil.

After that, the soil layer has been frozen in and preserved until today.

- DNA that is two million years old is astonishing and goes much further back in time than what has previously been managed to be extracted from sediment layers, says Love Dalén, who is a professor of evolutionary genomics at Stockholm University.

Two million-year-old DNA was found in soil layers like this.

Photo: Svend Funder

Have analyzed mammoth teeth

Love Dalén himself has analyzed DNA from mammoth teeth that have been frozen in the Siberian permafrost.

A geological dating shows that it lived 1.2 million years ago.

Analyzes of teeth and plant parts provide knowledge about these particular individuals.

But when you have analyzed sediment, you get fragments from the entire ecosystem and thus a much richer overall picture.

- These are really exciting results and open up a number of research areas to investigate how ecosystems have changed between ice ages that have come and gone, says Love Dalén.