Oldest DNA reveals life in Greenland 2 million years ago - ABC News

NEW YORK -- Scientists discovered the oldest known DNA and utilized it to uncover what beingness was similar 2 cardinal years agone successful the bluish extremity of Greenland. Today, it’s a barren Arctic desert, but backmost past it was a lush scenery of trees and vegetation with an array of animals, adjacent the present extinct mastodon.

“The survey opens the doorway into a past that has fundamentally been lost,” said pb writer Kurt Kjær, a geologist and glacier adept astatine the University of Copenhagen.

With carnal fossils hard to travel by, the researchers extracted biology DNA, besides known arsenic eDNA, from ungraded samples. This is the familial worldly that organisms shed into their surroundings — for example, done hair, waste, spit oregon decomposing carcasses.

Studying truly aged DNA tin beryllium a situation due to the fact that the familial worldly breaks down implicit time, leaving scientists with lone tiny fragments.

But with the latest technology, researchers were capable to get familial accusation retired of the small, damaged bits of DNA, explained elder writer Eske Willerslev, a geneticist astatine the University of Cambridge. In their study, published Wednesday successful the diary Nature, they compared the DNA to that of antithetic species, looking for matches.

The samples came from a sediment deposit called the Kap København enactment successful Peary Land. Today, the country is simply a polar desert, Kjær said.

But millions of years ago, this portion was undergoing a play of aggravated clime alteration that sent temperatures up, Willerslev said. Sediment apt built up for tens of thousands of years astatine the tract earlier the clime cooled and cemented the finds into permafrost.

The acold situation would assistance sphere the delicate bits of DNA — until scientists came on and drilled the samples out, opening successful 2006.

During the region's lukewarm period, erstwhile mean temperatures were 20 to 34 degrees Fahrenheit (11 to 19 degrees Celsius) higher than today, the country was filled with an antithetic array of works and carnal life, the researchers reported. The DNA fragments suggest a premix of Arctic plants, similar birch trees and willow shrubs, with ones that usually similar warmer climates, similar firs and cedars.

The DNA besides showed traces of animals including geese, hares, reindeer and lemmings. Previously, a dung beetle and immoderate hare remains had been the lone signs of carnal beingness astatine the site, Willerslev said.

One large astonishment was uncovering DNA from the mastodon, an extinct taxon that looks similar a premix betwixt an elephant and a mammoth, Kjær said.

Many mastodon fossils person antecedently been recovered from temperate forests successful North America. That’s an water distant from Greenland, and overmuch farther south, Willerslev said.

“I wouldn’t have, successful a cardinal years, expected to find mastodons successful bluish Greenland,” said Love Dalen, a researcher successful evolutionary genomics astatine Stockholm University who was not progressive successful the study.

Because the sediment built up successful the rima of a fjord, researchers were besides capable to get clues astir marine beingness from this clip period. The DNA suggests horseshoe crabs and greenish algae lived successful the country — meaning the adjacent waters were apt overmuch warmer backmost then, Kjær said.

By pulling dozens of taxon retired of conscionable a fewer sediment samples, the survey highlights immoderate of eDNA’s advantages, said Benjamin Vernot, an past DNA researcher astatine Germany’s Max Planck Institute for Evolutionary Anthropology who was not progressive successful the study.

“You truly get a broader representation of the ecosystem astatine a peculiar time,” Vernot said. “You don’t person to spell and find this portion of wood to survey this plant, and this bony to survey this mammoth.”

Based connected the information available, it’s hard to accidental for definite whether these taxon genuinely lived broadside by side, oregon if the DNA was mixed unneurotic from antithetic parts of the landscape, said Laura Epp, an eDNA adept astatine Germany’s University of Konstanz who was not progressive successful the study.

But Epp said this benignant of DNA probe is invaluable to amusement “hidden diversity” successful past landscapes.

Willerslev believes that due to the fact that these plants and animals survived during a clip of melodramatic clime change, their DNA could connection a “genetic roadmap” to assistance america accommodate to existent warming.

Stockholm University's Dalen expects past DNA probe to support pushing deeper into the past. He worked connected the survey that antecedently held the “oldest DNA” record, from a mammoth bony astir a cardinal years old.

“I wouldn’t beryllium amazed if you tin spell astatine slightest 1 oregon possibly a fewer cardinal years further back, assuming you tin find the close samples,” Dalen said.

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