A team of scientists has discovered the oldest known DNA and used it to reveal what life looked like 2 million years ago at the northern tip of Greenland.
Today Greenland is a barren desert in the Arctic, but back then it was a lush landscape filled with trees and plants and an array of animals, including the now-extinct mastodon, according to the Associated Press.
Uncover the secrets of a deep past
Lead researcher Kurt Kjaer, a geologist and expert on glaciers at the University of Copenhagen, said the study opens a window into the secrets of a distant past.
With animal fossils so hard to come by, researchers extracted environmental DNA, also known as eDNA, from soil samples. eDNA is the genetic material that organisms shed into their surroundings, for example hair, excrement, spit or decomposing corpses.
Greenland
Latest technology
Studying ancient DNA can be a challenge because the genetic material degrades over time, leaving only tiny fragments for scientists. But researcher Eske Willerslev, a geneticist at the University of Cambridge, explained that with the latest technology, researchers were able to obtain genetic information from small damaged fragments of DNA, as the DNA of different species was compared in search of matches, according to the journal Nature.
severe climate change
The scientists obtained the samples from a sediment called the Cap Copenhaven Formation in Berryland. Kiar said that the region today is a polar desert, while Willerslev explained that millions of years ago this region was going through a period of severe climate change that led to a rise in temperatures. Sediments likely accumulated for tens of thousands of years at the site before the climate cooled and stabilized the finds in the permafrost.
Greenland
Trees and plants
Researchers report that during the region’s warm period, when average temperatures were 11 to 19 degrees Celsius higher than they are today, the region was filled with an extraordinary array of plant and animal life. The DNA fragments point to a mixture of arctic plants, such as birch trees and willow bushes, with those that usually prefer warmer climates, such as fir and cedars.
Animals and marine life
Wellerslev said the DNA showed traces of animals, including geese, hares and reindeer. Previously, dung beetles and some rabbit remains were the only signs of animal life at the site.
Kyarr added that one of the big surprises was finding DNA from a mastodon, an extinct species that looked like a cross between an elephant and a mammoth.
Many mastodon fossils were previously found in the temperate forests of North America. It’s an ocean farther south than Greenland, Wellerslev said.
Because sediments accumulated at the mouth of the fjord, the researchers were also able to obtain clues regarding marine life from this time period. The DNA indicates that horseshoe crabs and green algae lived in the area, which Kyarr said meant the nearby waters were likely much warmer at the time.
road map
Researcher Willerslev believes that these plants and animals survived during a period of dramatic climate change, so their DNA might provide a “genetic roadmap” to help us adapt to current warming.
