Known worldwide as “the land of the midnight sun,” the sun remains high in the Greenland sky throughout the entire summer, the country bathed in golden light for weeks on end. The literal endless days of summer make the country sound like a warm, possibly even tropical, place. In reality, however, the Greenland of today is a polar desert, its icy landscape covered in snow and enormous icebergs – but it wasn’t always that way.
As scientists have discovered, Greenland was once “a forested ecosystem unlike any now found on Earth.” In a new study published in Nature this week, researchers revealed how their 2-million-year-old DNA discovery provided a look into Greenland’s lush past.
“A new chapter spanning one million extra years of history has finally been opened. For the first time, we can look directly at the DNA of a past ecosystem that far back in time. DNA can degrade quickly,” Eske Willerslev, one of the researchers, said in a press release. “But we’ve shown that under the right circumstances, we can now go back further in time than anyone could have dared imagine.”
“The study opens the door into a past that has basically been lost,” added lead author Kurt Kjær.
Using Historic DNA Discovery, Scientists Learn Mastodons Once Roamed Greenland
Through their research following the fascinating DNA discovery, scientists determined that the now-barren desert used to be covered in trees and vegetation housing a wide range of wildlife, including the mastodon.
To do so, they analyzed small, damaged fragments of DNA found in a sediment deposit called the Kap København formation. They then compared their findings to the DNA of species of today, hoping to find a match. “I wouldn’t have, in a million years, expected to find mastodons,” said Love Dalen, a researcher in evolutionary genomics.
“You really get a broader picture of the ecosystem at a particular time,” said Benjamin Vernot, ancient DNA researcher. “You don’t have to go and find this piece of wood to study this plant. Or this bone to study this mammoth.”
According to scientists, the DNA was preserved for so long thanks to intense climate change. Millions of years ago, the temperatures in Greenland spiked upward before eventually cooling, cementing the DNA into the permafrost.
During the country’s warm period, the average temperatures were around 20-30 degrees higher than today. This supported a wide array of plant and animal life, including both Artic species and those that prefer warmer climates. The DNA held traces of birch trees, willow shrubs, firs, and cedars, as well as geese, hares, reindeer, and lemmings.
The discovery of mastodon DNA was shocking, but it was the deer DNA that truly left scientists dumbfounded. “Reindeers, according to paleontologists, should not have survived,” Eske Willerslev said. “They shouldn’t even exist at that time.”