London: Scientists have stumbled upon two-million-year-old DNA for the first time — breaking the record of world’s oldest DNA discovery by one million years and opening a ‘game-changing’ new chapter in the history of evolution.
Microscopic fragments of environmental DNA were found in Ice Age sediment in northern Greenland.
Using cutting-edge technology, researchers discovered the fragments are one million years older than the previous record for DNA sampled from a Siberian mammoth bone.
The team of scientists, led by Professor Eske Willerslev from St John’s College at University of Cambridge and geology expert Kurt H. Kjaer from Lundbeck Foundation GeoGenetics Centre at the University of Copenhagen, hope the results could help to predict the long-term environmental toll of today’s global warming.
“A new chapter spanning one million extra years of history has finally been opened and for the first time we can look directly at the DNA of a past ecosystem that far back in time. DNA can degrade quickly but we’ve shown that under the right circumstances, we can now go back further in time than anyone could have dared imagine,” Willerslev said in a paper published in Nature.
The ancient DNA samples were found buried deep in sediment that had built-up over 20,000 years.
“The sediment was eventually preserved in ice or permafrost and, crucially, not disturbed by humans for two million years,” said Professor Kjaer.
The climate in Greenland at the time varied between Arctic and temperate and was between 10-17 degree Celsius warmer than Greenland is today.
Scientists discovered evidence of animals, plants and microorganisms including reindeer, hares, lemmings, birch and poplar trees. Researchers even found that Mastodon, an Ice Age mammal, roamed as far as Greenland before later becoming extinct.
The two-million-year-old samples also help academics build a picture of a previously unknown stage in the evolution of the DNA of a range of species still in existence today.
(IANS)
