Discovery of oldest ever DNA could explain how humans evolved

DNA dating back two million years has been discovered in the oldest example of genetic material ever found.

The finding from Greenland opens the possibility that DNA could be recovered dating back from the earliest days of humanity, helping to explain how humans evolved or uncover lost species.

Until now the earliest genetic material came from a one million year old Siberian mammoth bone.

But genetic fragments from species including reindeer, hares, lemmings, birch and poplar trees, as well as the extinct giant mastodon, were found in sediment in the mouth of a fjord in the Arctic Ocean in Greenland’s northernmost point.

The DNA had survived in dry and freezing clay and quartz deposits in ancient sediment deposits known as the København Formation, dating back two million years.

The team believes that clay may also have preserved ancient DNA in warm, humid environments in sites found in Africa, leaving genetic traces of our human ancestors.

'One million extra years of history has been opened'

Professor Eske Willerslev, of the University of Cambridge, said: “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.

“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.

“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.”

The deposits were laid down at a time when Greenland was 10 to 17C warmer than today, and showed that traditionally Arctic species can adapt and survive large temperature changes offering hope that they would survive climate change.

The team is hoping that the DNA will give clues as to how the plants and animals adapted.

Professor Kurt Kjær, of the University of Copenhagen, added: “It is possible that genetic engineering could mimic the strategy developed by plants and trees two million years ago to survive in a climate characterised by rising temperatures and prevent the extinction of some species, plants and trees.

“This is one of the reasons this scientific advance is so significant because it could reveal how to attempt to counteract the devastating impact of global warming.”

The research was published in the journal Nature.