A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA

Late Pliocene and Early Pleistocene epochs 3.6 to 0.8 million years ago(1) had climates resembling those forecasted under future warming(2). Palaeoclimatic records show strong polar amplification with mean annual temperatures of 11-19 & DEG;C above contemporary values(3,4). The biological communities inhabiting the Arctic during this time remain poorly known because fossils are rare(5). Here we report an ancient environmental DNA(6) (eDNA) record describing the rich plant and animal assemblages of the Kap Kobenhavn Formation in North Greenland, dated to around two million years ago. The record shows an open boreal forest ecosystem with mixed vegetation of poplar, birch and thuja trees, as well as a variety of Arctic and boreal shrubs and herbs, many of which had not previously been detected at the site from macrofossil and pollen records. The DNA record confirms the presence of hare and mitochondrial DNA from animals including mastodons, reindeer, rodents and geese, all ancestral to their present-day and late Pleistocene relatives. The presence of marine species including horseshoe crab and green algae support a warmer climate than today. The reconstructed ecosystem has no modern analogue. The survival of such ancient eDNA probably relates to its binding to mineral surfaces. Our findings open new areas of genetic research, demonstrating that it is possible to track the ecology and evolution of biological communities from two million years ago using ancient eDNA.

Automated summary

Research reveals the existence of rich plant and animal communities in North Greenland two million years ago. The ancient community consisted of an open boreal forest with a variety of Arctic and boreal shrubs and herbs. Genetic analysis confirms the presence of ancestral species such as hares, mastodons, reindeer, rodents, and geese. The presence of marine organisms suggests a warmer climate than today. The findings open new possibilities for genetic research, demonstrating the use of ancient environmental DNA to track the ecology and evolution of biological communities from two million years ago.