2 million-year-old DNA, the oldest-ever, uncovers Greenland's lost world
Two million-year-old DNA fragments, found in frozen soil in the northeastern tip of Greenland, are the oldest DNA ever obtained. Researchers said that this region was once a 'forested ecosystem' and was home to poplar trees, reindeer, mastodons, geese, and other species. Mastodons, a now-extinct elephantine mammal, lived in North American forests and their remains have never been found in Greenland before.
Why does this story matter?
The current advances in DNA extraction techniques have enabled this discovery, and some of these samples were collected back in 2006. This discovery also demonstrates the potential of ancient sedimentary DNA in providing valuable insights into past ecosystems. Previously, the record for the oldest DNA was held by a million-year-old mammoth sample found in northeastern Siberia in 2021.
The detected samples of marine species indicate a warmer climate
The extracted DNA samples, from Kap Kobenhavn Formation, were traced to more than 135 species. The planet varieties include poplar, spruce, and yew trees, which are usually found in lower altitudes. The DNA record also confirmed the presence of hares, mastodons, reindeer, rodents, and geese. Marine species including horseshoe crabs and green algae were detected which indicates that the climate must have been warmer.
Scientists are also probing 4 million-year-old sites in Canada
The current study suggests that the DNA molecules were bound to minerals of feldspar and clay, which protected them from damage and helped them survive. The same research team is also probing four million-year-old sites in northern Canada. Given the damages detected in the oldest DNA, scientists state that it might not be possible to recover genetic material older than five million years.
Clay might have preserved ancient DNA in humid conditions
"DNA generally survives best in cold, dry conditions such as those that prevailed during most of the period since the material was deposited at Kap Kobenhavn," said Professor Eske Willerslev, lead researcher. "Now that we have successfully extracted ancient DNA from clay and quartz, it may be possible that clay may have preserved ancient DNA in warm, humid environments in sites found in Africa."
Exploring age-old DNA might reveal 'ground-breaking information'
"If we can begin to explore ancient DNA in clay grains from Africa, we may be able to gather ground-breaking information about the origin of many different species—perhaps even new knowledge about the first humans and their ancestors—the possibilities are endless," said Professor Willerslev.
