環境DNAが解き明かすグリーンランドでの200万年前の生態系(Environmental DNA uncovers a 2-million-year-old ecosystem in Greenland)


2022-12-07 ローレンスリバモア国立研究所(LLNL)





カナダ北極圏のエルズミア島にある340万年前のファイルスリーフベッドとビーバーポンドには、絶滅したクマ(Protarctos abstrusus)、巨大ビーバー(Dipoides sp.)、小型イヌ(Eucyon)、北極の巨大カマキリ(C.f. Paracamelus0)といったグリーンランドに入植した可能性のある哺乳類の化石が保存されている。




環境DNAが解き明かす、グリーンランドに残る200万年前の生態系 A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA

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 & Eske Willerslev

Nature  Published:07 December 2022


figure 1


Late Pliocene and Early Pleistocene epochs 3.6 to 0.8 million years ago1 had climates resembling those forecasted under future warming2. Palaeoclimatic records show strong polar amplification with mean annual temperatures of 11–19 °C above contemporary values3,4. 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.