Friday, December 9, 2022

[Paleontology • 2022] A 2-Million-year-old Ecosystem in Greenland uncovered by environmental DNA


the rich plant and animal assemblages of the Kap København Formation in North Greenland.

in Kjær, Pedersen, Sanctis, Cahsan, Korneliussen, ... et Willerslev, 2022. 
 — image: Beth Zaiken/bethzaiken.com

Abstract
Late Pliocene and Early Pleistocene epochs 3.6 to 0.8 million years ago had climates resembling those forecasted under future warming. Palaeoclimatic records show strong polar amplification with mean annual temperatures of 11–19 °C above contemporary values. The biological communities inhabiting the Arctic during this time remain poorly known because fossils are rare5. Here we report an ancient environmental DNA6 (eDNA) record describing the rich plant and animal assemblages of the Kap København 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.



Kurt H. Kjær, Mikkel Winther Pedersen, Bianca De Sanctis, Binia De Cahsan, Thorfinn S. Korneliussen, Christian S. Michelsen, Karina K. Sand, Stanislav Jelavić, Anthony H. Ruter, Astrid M. A. Schmidt, Kristian K. Kjeldsen, Alexey S. Tesakov, Ian Snowball, John C. Gosse, Inger G. Alsos, Yucheng Wang, Christoph Dockter, Magnus Rasmussen, Morten E. Jørgensen, Birgitte Skadhauge, Ana Prohaska, Jeppe Å. Kristensen, Morten Bjerager, Morten E. Allentoft, Eric Coissac, PhyloNorway Consortium, Alexandra Rouillard, Alexandra Simakova, Antonio Fernandez-Guerra, Chris Bowler, Marc Macias-Fauria, Lasse Vinner, John J. Welch, Alan J. Hidy, Martin Sikora, Matthew J. Collins, Richard Durbin, Nicolaj K. Larsen and Eske Willerslev. 2022. A 2-Million-year-old Ecosystem in Greenland uncovered by environmental DNA. Nature. 612; 283–291. DOI: 10.1038/s41586-022-05453-y
 https://phys.org/news/2022-12-discovery-world-oldest-dna-million.html
 
 
The lost world: The cover shows an artist’s impression of the rich ecosystem that existed in parts of northern Greenland some 2 million years ago. The ecosystem is reconstructed from ancient DNA in this week’s issue by Eske Willerslev and colleagues. Working at the Kap København Formation in Peary Land, the researchers gathered sediment samples rich in organic material from 5 different geological sites. By extracting and sequencing DNA from these samples, they were able to piece together a picture of the flora and fauna present around 2 million years ago. The team found evidence of open boreal forest mixed with Arctic species such as cedar, spruce and birch, as well as signs of animals including hares, mastodons, reindeer and geese. The evidence affirms that this part of Greenland, now a polar desert, was 11–17 °C warmer than it is today and suggests it was home to an ecosystem composition that no longer exists anywhere in the world.
 — Cover image: Beth Zaiken/bethzaiken.com twitter.com/BZaiken