They sequence the DNA of the Greenland ecosystem and find traces of an ancient elephant. « We thought he lived only in North America»- Corriere.it

«Traces» of a great variety of plants, fish, insects, fleas, rabbits, ducks, different types of rodents and even some reindeer. Even an ancient mastodon (the American mammoth) and marine plankton. Of poplars and deciduous trees that are usually found in boreal forests and which instead were found in the northernmost tip of Greenland where, now, there is practically no life (with the exception of some lichens and mosses). That’s what an international team of researchers has discovered by analyzing a series of DNA samples dating back two million years and which could demonstrate how, in the polar desert of Greenland, a much warmer climate, 10 to 17 degrees warmer, supported an ecosystem teeming with a wide diversity of plants and animals. The DNA studied is the oldest that has ever been analysed. Previously, the oldest known recovered DNA was 1 million years old and came from a Siberian mammoth tooth preserved in permafrost that provided limited information about its surroundings.

The work required a detective investigation of more than 16 years by scientists and its results were published on December 7 by the journal Nature. The study, led by evolutionary geneticist Eske Willerslev, a professor at the University of Cambridge, could help researchers understand what to expect in a warmer future and provide clues as to how Greenland’s local ecosystem has been able to adapt to climate warming in the last two million years. “DNA evidence could provide clues about how these life forms survived extreme temperatures and how nature may respond to rising temperatures,” Willerslev explained. It’s actually very similar climate to what we expect to face on Earth due to global warming.”

The most startling discovery was the mastodon, an ancient relative of the elephant and which has long been associated with the boreal forests of North America. According to Willerslev, he probably traveled to Greenland across the ice with reindeer. “Not even in a million years would you expect to find a mastodon up there,” said Love Dalén, a paleontologist at the Natural History Museum of Sweden. but among the material found, also the DNA of blue algae to indicate the presence of a much hotter climate than today. “The two things that strike me are the age and diversity of the DNA analysed,” said Matthew Barnes, an ecologist at Texas Tech University who was not involved in the study. In fact, the team’s analysis was not aimed at tissue or feces but at an entire community of life forms . “It almost seems like magic to be able to study such a complete picture of an ancient ecosystem from tiny fragments of DNA that have been preserved over time,” said Beth Shapiro, paleogeneticist at the University of California at Santa Cruz to the New York Times. The analyzed DNA includes fragments of flowering plants and trees, species that have not existed in the area for a long time

The genetic material was harvested from ancient sediments in Greenland, an area of ​​the planet that once had a much warmer climate and has allowed a rich ecosystem of flora and fauna to thrive. Some of the samples analyzed by the researchers were taken from a deposit of clay and sand found in 2006, after being stored in Copenhagen. “The climate was similar to what we expect to face on Earth in the coming years due to global warming,” said Eske Willerslev of the University of Copenhagen. “The research will provide us with insights and data to understand how nature can respond to rising temperatures.”