Dec 09, 2022 I Paul Seaburn

Oldest DNA Ever Found Reveals the Lost World of Greenland 2 Million Years Ago

Few countries are less aptly named than Greenland and Iceland. While its name says ‘ice’, the land of Iceland is located completely outside the Arctic Circle and is bathed in the warm North Atlantic Current which keeps its coasts ice-free through the winter and its land covered with greenery except where it is affected by volcanoes or human development. On the other hand, Greenland is home to the lowest temperature ever recorded in the Northern Hemisphere as might be expected of an island mostly inside the Arctic Circle and nearly covered year-round by a sheet of ice - so much so that the northern portions are called a polar desert. Fans of Greenland defend it by saying that it was once covered in lush greenery and befitting of its modern name, but that is hard to believe without proof. Well, get ready to cheer, Greenland fans -- the proof is in the DNA pudding. Scientists in Greenland have found the oldest DNA ever – two million years old – and it reveals that the lost ecology of the island was filled with birch and poplar trees, mastodons, reindeer, geese, horseshoe crabs, algae and much, much more.

Can you imagine Greenalnd covered with lush forest of birch trees?

“For many years, people did not bother very much with places like northern Canada or northern Greenland, because you couldn't expect to find very much. We only had our dreams and our imagination.”

Ross MacPhee, senior curator at the American Museum of Natural History and an expert in Ice Age mammals who was not involved in the study, tells Nova that he felt the same frustration as many scientists and museum curators did when they looked around and saw no records of the flora and fauna of prehistoric Greenland. Without fossils or DNA, which in Greenland are buried under layers of ice, it has been impossible to get a good impression of what it looked like before the climate changed and the ice took over. That has changed recently with the advent of environmental DNA (eDNA) - organismal DNA which originates from cellular material shed by organisms via skin, excrement, leaves, etc. into water or soil that can now be sampled and studied using state-of-the-art molecular analysis technology. Scientists soon found that archeological sites with few or no fossils still had ancient environmental DNA.

“The huge damage pattern made it very clear it was ancient DNA. When it's 2 million years, there has been so much evolutionary time, that whatever [species] you are finding are not necessarily very similar to what you see today. You know exactly that at this time, and this place, these organisms were together.”

Eske Willerslev of the University of Copenhagen led the study which was published this week in the journal Nature. He tells the MIT Technology Review that he and his team began working with samples from the Greenland sediment layers back in 2006. The 41 samples were found buried in the Kap København Formation, a 300-feet-deep sediment deposit located in the mouth of a fjord in the Arctic Ocean at Greenland’s northernmost point (just 600 miles from the North Pole) that took 20,000 years to form. The first major discovery was that the sediment layer dated back 2 million years to the Late Pliocene and Early Pleistocene epochs. These eras were 3.6 to 0.8 million years ago and little is know of the plants and animals of the time. That changed in 2017 with the second major discovery by the team - ancient environmental DNA samples preserved by ice and permafrost and undisturbed for 2 million years – a record for ancient DNA by one million years!

“It was a breakthrough. It was going from nothing or very little that you don’t know is real, to suddenly: It’s there.”

Willerslev, who is a pioneer in the study of eDNA, told The New York Times that the research team sorted the samples with DNA sequences of living species and identified 102 different kinds of plants — 78 that had previously been identified from fossils and 24 new ones. This proved that northern Greenland 2 million years ago was covered with forests of predominantly  poplar and birch trees, with Arctic shrubs, herbs, ferns and mosses growing among them. Once they sorted out the plants, the team moved on to animals. The eDNA showed that Greenland of 2 million years ago was more like a modern wildlife safari park than a polar desert – they managed to identify DNA from caribou, Arctic hares, mastodons, geese, lemmings and ants.

“What the hell are they doing up there?”

The mastodons were a shocker to Love Dalén, a paleogeneticist from Stockholm University who discovered mammoth DNA in Siberia that was 1.2 million years old. Until now, the nearest known mastodon fossils were 75,000-year-old remains found in Nova Scotia much farther south than Kap Kobenhavn. The study team determined that the Greenland mastodons belonged to a previously unknown and very deep branch of the mastodon family tree. In fact, Dalén thinks it might be a new species that thrived in the poplar and birch forests of Greenland long before its mastodon relatives did the same in North America. Finding caribou in this warm ancient Greenland forest was also a surprise – the species today prefers northern tundras. However, the next big shocker was not on land but on the beach and in the water -- horseshoe crabs. This supports the new idea that North Greenland of two million years ago was much warmer than it is today – with an average annual temperature projected to be about 11-19C (51.8-66.2F) … making the coastal ocean waters and internal lakes downright balmy.

"What it really tells us is that the plasticity of biological organisms - in terms of where they can live and the plants or animals that can live together - is way larger than what we thought."

Willerslev doesn’t just see the Greenalnd of 2 million years ago as a paradise of plants and animals -- he also sees it as a place where a wide variety of them managed to live, thrive and get along. That makes this new discovery both scientific and sociological – it proves that environmental DNA can survive far longer than previously thought, which will open the doors to finding more ancient lost worlds and the flora and fauna that lived in them. It also shows that diversity does not mean conflict and competition – the plants and animals on ancient Greenland were varied, populous and thriving, Only the advent of an ice age could destroy the harmony of an ancient Greenland that truly lived up to its modern name.

It sounds much better than a turndra.

“I think it’s going to blow people’s minds. It certainly did so for me.”

Andrew Christ, a geoscientist at the University of Vermont who studies the ancient Arctic and was not part of the study, thinks this is a game-changer for the use of environmental DNA to travel far back in time and get an accurate picture of ancient life without the need for fossils. Because the Greenland of 2 million years ago looks nothing like any area on earth today, he also sees using eDNA as a way to determine how climate change today will affect our modern plants and animals. He ends with a warning from 2 million years ago:

“Life will adapt, but in ways we don’t expect.”

Paul Seaburn

Paul Seaburn is the editor at Mysterious Universe and its most prolific writer. He’s written for TV shows such as "The Tonight Show", "Politically Incorrect" and an award-winning children’s program. He's been published in “The New York Times" and "Huffington Post” and has co-authored numerous collections of trivia, puzzles and humor. His “What in the World!” podcast is a fun look at the latest weird and paranormal news, strange sports stories and odd trivia. Paul likes to add a bit of humor to each MU post he crafts. After all, the mysterious doesn't always have to be serious.

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