Scientists have identified DNA of animals, plants and microbes dating back about 2 million years – by far the oldest ever recorded – from sediments unearthed at the northernmost point of Greenland excavated around the mouth of an Arctic Ocean fjord. revealing an incredible lost world on this remote frontier.
Researchers said Wednesday that DNA fragments have been detected in a range of animals, including mastodons, reindeer, hares, lemmings and geese, as well as plants, including poplars, birches and thujas, and microorganisms, including bacteria and fungi. DNA is the self-replicating material that carries genetic information in living organisms, a kind of blueprint for life.
The mastodon was a relative of the elephant that roamed North and Central America until its extinction along with many other large Ice Age mammals about 10,000 years ago. The discovery shows that it had a wider range than previously known.
“The mastodon was a big surprise. It had never been found in Greenland before. However, the biggest surprise was this unique ecosystem of mixed temperate and arctic species with no modern analogues,” said Eske Willerslev, director of the Lundbeck Foundation GeoGenetics Center and responsible for the study published in the journal Nature.
“I don’t think anyone could have predicted that Greenland would be home to such a diversity of plants and animals 2 million years ago when the climate was very similar to what we expect to see in a few years due to global warming.” added Willerslev, who is affiliated with the University of Cambridge and the University of Copenhagen.
While ancient DNA is highly perishable, the study showed that under the right conditions – in this case, permafrost – it can survive longer than previously thought possible. Willerslev said he now wouldn’t be surprised to find DNA from at least 4 million years ago.
The researchers extracted and sequenced DNA from 41 organic matter-rich sediment samples obtained from five sites on the Peary Land peninsula, which juts out into the Arctic Ocean. Microscopic fragments of DNA were extracted from the clay and quartz in the sediment. They identified over 100 types of animals and plants.
The samples were first unearthed in 2006, but previous DNA detection attempts have failed. The methods used to extract ancient DNA have since improved, eventually allowing for a breakthrough.
“We think it’s because the DNA bound to the mineral particles has allowed it to survive beyond what was thought possible. The binding reduces the rate of spontaneous chemical degradation,” Willerslev said.
The oldest recorded predecessor DNA was extracted from the molar of a mammoth, another relative of the elephant, in northeastern Siberia, dating back to 1.2 million years ago, also preserved in permafrost conditions. By way of comparison, our own species, Homo sapiens, appeared about 300,000 years ago.
Most of modern Greenland is covered in a thick layer of ice, with ice-free areas along the coast. The region under consideration is considered a polar desert. But 2 million years ago, average temperatures in Greenland were 11°C to 17°C higher, according to the study’s first author, Kurt Kjaer of the University of Copenhagen.
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Source: Terra
Camila Luna is a writer at Gossipify, where she covers the latest movies and television series. With a passion for all things entertainment, Camila brings her unique perspective to her writing and offers readers an inside look at the industry. Camila is a graduate from the University of California, Los Angeles (UCLA) with a degree in English and is also a avid movie watcher.
