In a region known as Peary Land at the northern tip of Greenland, researchers uncovered an ancient ecosystem containing two-million-year-old DNA—the world’s oldest known thus far.
The area is now nothing but a polar desert. However, it once was home to lush trees as well as caribou and mastodons. It now provides astounding insight into our planet during its warmer periods in history.
Despite drastic climate changes over thousands of years, some species have managed to migrate and adapt to the extremely cold temperatures found in Arctic environments.
Others, however, have been limited by their more temperate-adapted features and are only able to live amongst boreal forests today.
Eske Willerslev, an evolutionary geneticist at the University of Cambridge and the study’s lead author, says this is “what we see is an ecosystem with no modern analogue.” The study was published in Nature.
The world’s oldest DNA found thus far
An exciting discovery in Peary Land has revolutionized our understanding of ancient DNA. By analyzing a fossil-rich rock formation called Kap København, researchers have been able to uncover previously unprecedented old, organic material that is over one million years old from both land and an estuary.
This remarkable find is even older than the recovered mammoth tooth or marine sediments from Antarctica.
Geologists were amazed to find fossils dating back two million years ago that yielded a wealth of plant and insect remains but surprisingly few mammals.
However, DNA analysis recently revealed an incredible range of organisms—102 types of plants, including twenty-four never before seen in the formation. Amongst these were horseshoe crabs, hares, geese, and even mastodons.
This discovery left researchers absolutely astonished. Previous studies had suggested that mastodons did not venture so far north—until now.
Dr. Drew Christ, a postdoctoral fellow at the University of Vermont’s Gund Institute for Environment and expert in polar regions, said, “It’s painting a picture of everything that was present in this ecosystem, and that is really incredible.”
Ancient Peary Land reconstruction
Through the mysterious power of eDNA, researchers were able to miraculously reconstruct ancient Peary Land.
This incredible feat was made possible when DNA fragments began entering the environment from sources such as tree leaves and skin flakes through a process known as molecular binding. They connected with sediments, safeguarding them against destruction by enzymes.
Karina Sand’s involvement in this project serves to highlight just how far science can take us into times long forgotten!
After beginning their mission in 2006, researchers set out to collect sediments from Peary Land. However, despite the ambition and dedication of the team, it took years for them to make a breakthrough. They kept facing failure when attempting DNA extraction using the most recent sequencing technology.
Willerslev said, “Every time we had improvements in terms of DNA extraction and sequencing technology, we tried to revisit these samples—and we failed, and we failed.”
It was only after technological advancements provided more precise tools that this determined group finally achieved success in extracting usable ancient DNA samples from sediment deposits.
Kap København as a forested coastline
Two million years ago, the beautiful coast of what is now Kap København was a lush forest with an estuary at its edge.
DNA fragments carried by a river from land to sea were preserved in this marine environment, offering ancient glimpses into species long since gone and those that still remain today.
Remarkably, evidence has been discovered for creatures as diverse as horseshoe crabs (which have since migrated southward), caribou, coral formations, ants, fleas, and even lemmings.
Despite the hostile climate of constant darkness for half the year, Greenland was able to sustain a thriving landscape in times past, one with tree varieties such as willow, birch, and poplar.
Due to evolutionary adaptation, these plants were equipped to thrive even under extreme conditions in which temperatures averaged eleven to nineteen degrees Celsius hotter than those of our present time.
The study’s co-author, Mikkel Pedersen, attests that this powerful feat is an impressive testament to nature’s ability to adjust.