How the discovery of the world’s oldest DNA could help endangered species

By Stephen Beech via SWNS

The discovery of the world’s oldest DNA - dating back two million years - could help make some of today's most endangered species more resistant to global warming.

Scientists say that the identification of the DNA - one million years older than the previous record - has opened 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 state-of-the-art technology, researchers discovered the fragments are one million years older than the previous record for DNA sampled from a Siberian mammoth bone.

The ancient DNA has been used to map a two-million-year-old ecosystem that scientists say weathered extreme climate change.

They hope the results could help to predict the long-term environmental toll of today’s climate change.

The results of the 41 usable samples found hidden in clay and quartz were published in the journal Nature.

The discovery was made by a research team led by Professor Eske Willerslev and Professor Kurt Kjær.

Prof Willerslev, a Fellow of St John’s College, Cambridge, said: “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.”

Professor Kjær,a geology expert at the University of Copenhagen, Denmark, said: “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.”

The incomplete samples, a few millionths of a millimeter long, were taken from the København Formation, a sediment deposit almost 100 meters thick in the mouth of a fjord in the Arctic Ocean in Greenland’s northernmost point.

The climate in Greenland at the time varied between Arctic and temperate and was between 10C and 17C warmer than Greenland is today. The sediment built up meter by meter in a shallow bay.

Scientists discovered evidence of animals, plants and microorganisms - including reindeer, hares, lemmings, birch and poplar trees.

The team even found that Mastodon, an Ice Age mammal, roamed as far as Greenland before later becoming extinct.

Previously it was thought the range of the elephant-like animals did not extend as far as Greenland from its known origins of North and Central America.

Detective work by 40 researchers from all over Europe and the United States unlocked the secrets of the fragments of DNA.

They described the process as "painstaking" as first they needed to establish whether there was DNA hidden in the clay and quartz, and if there was, whether they could successfully detach the DNA from the sediment to examine it.

The team compared every single DNA fragment with extensive libraries of DNA collected from present-day animals, plants and microorganisms.

A picture began to emerge of the DNA from trees, bushes, birds, animals and microorganisms.

Some of the DNA fragments were easy to classify as predecessors to present-day species, while some originated from species impossible to place in the DNA libraries of animals, plants and microorganisms still living today.

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.

Professor Kjær said: “Many of the samples were taken back in 2006 when the team were in Greenland for another project, they have been stored ever since.

“It wasn’t until a new generation of DNA extraction and sequencing equipment was developed that we’ve been able to locate and identify extremely small and damaged fragments of DNA in the sediment samples.

"It meant we were finally able to map a two-million-year-old ecosystem.”

Study co-first author Dr Mikkel Pedersen said: “The Kap København ecosystem, which has no present-day equivalent, existed at considerably higher temperatures than we have today - and because, on the face of it, the climate seems to have been similar to the climate we expect on our planet in the future due to global warming.

“One of the key factors here is to what degree species will be able to adapt to the change in conditions arising from a significant increase in temperature.

"The data suggests that more species can evolve and adapt to wildly varying temperatures than previously thought.

"But, crucially, these results show they need time to do this.

"The speed of today’s global warming means organisms and species do not have that time so the climate emergency remains a huge threat to biodiversity and the world – extinction is on the horizon for some species including plants and trees.”

The team hope that some of the "tricks" of the two-million-year-old plant DNA found may be used to help make some endangered species more resistant to a warming climate.

Kjær said: “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.”

Willerslev added: “DNA generally survives best in cold, dry conditions.

"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.

“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.”