Depiction of Greenland half a million years ago
Scientists using DNA extracted from ice buried deep below the surface have found evidence that a lush forest once existed in southern Greenland, a finding that sheds light on how climate change affects Earth's frozen areas.
The researchers analyzed ice cores 2-3 km below the surface from several locations in southern Greenland and discovered what they believe to be the oldest authenticated DNA ever recorded.
> Dye 3: 2km long ice core
> Greenland Ice Core Project (GRIP): 3km long ice core
> John Evans Glacier (JEG): Control site
> Kap Kobenhavn: Previously youngest known Greenland forest
At present, glaciers cover about 10% of Earth's terrestrial surface, but there is only limited knowledge about the biota that occupied these vast areas before the ice formed; most fossil evidence is either deeply hidden or has been scoured away during periods of glacial expansion. Willerslev et al. (p. 111; see the news story by Curry) were able to extract and amplify ancient DNA reproducibly from plants and insect remains from the silty sections of deep ice cores from just above the bedrock. At the time when this ice formed, southern Greenland was covered by a diverse boreal forest consisting of pine, spruce, alder, and yew and inhabited by insects such as butterflies and moths. These results could be indicative of either extensive deglaciation of southern Greenland during the last interglacial (Eemian) or DNA survival over longer time scales of up to 1 million years.
Science 6 July 2007:
Vol. 317. no. 5834, pp. 111 - 114
DOI: 10.1126/science.1141758
Ancient Biomolecules from Deep Ice Cores Reveal a Forested Southern Greenland
Ancient Biomolecules from Deep Ice Cores Reveal a Forested Southern Greenland
Eske Willerslev,1* Enrico Cappellini,2 Wouter Boomsma,3 Rasmus Nielsen,4 Martin B. Hebsgaard,1 Tina B. Brand,1 Michael Hofreiter,5 Michael Bunce,6,7 Hendrik N. Poinar,7 Dorthe Dahl-Jensen,8 Sigfus Johnsen,8 J�rgen Peder Steffensen,8 Ole Bennike,9 Jean-Luc Schwenninger,10 Roger Nathan,10 Simon Armitage,11 Cees-Jan de Hoog,12 Vasily Alfimov,13 Marcus Christl,13 Juerg Beer,14 Raimund Muscheler,15 Joel Barker,16 Martin Sharp,16 Kirsty E. H. Penkman,2 James Haile,17 Pierre Taberlet,18 M. Thomas P. Gilbert,1 Antonella Casoli,19 Elisa Campani,19 Matthew J. Collins2
It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of past flora and fauna. We show that high-altitude southern Greenland, currently lying below more than 2 kilometers of ice, was inhabited by a diverse array of conifer trees and insects within the past million years. The results provide direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.
1 Centre for Ancient Genetics, University of Copenhagen, Denmark.
2 BioArch, Departments of Biology and Archaeology, University of York, UK.
3 Bioinformatics Centre, University of Copenhagen, Denmark.
4 Centre for Comparative Genomics, University of Copenhagen, Denmark.
5 Max Planck Institute for Evolutionary Anthropology, Germany.
6 Murdoch University Ancient DNA Research Laboratory, Murdoch University, Australia.
7 McMaster Ancient DNA Center, McMaster University, Canada.
8 Ice and Climate, University of Copenhagen, Denmark.
9 Geological Survey of Denmark and Greenland, Denmark.
10 Research Laboratory for Archaeology and the History of Art, University of Oxford, UK.
11 Department of Geography, Royal Holloway, University of London, UK.
12 Department of Earth Sciences, University of Oxford, UK.
13 Paul Scherrer Institut (PSI)/Eidgen�ssische Technische Hochschule (ETH) Laboratory for Ion Beam Physics, Institute for Particle Physics, ETH Zurich, Switzerland.
14 Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Switzerland.
15 GeoBiosphere Science Center, Lund University, Sweden.
16 Department of Earth and Atmospheric Sciences, University of Alberta, Canada.
17 Ancient Biomolecules Centre, Oxford University, UK.
18 Laboratoire d'Ecologie Alpine, CNRS Unit� Mixte de Recherche 5553, Universit� Joseph Fourier, Bo�te Postale 53, 38041 Grenoble Cedex 9, France.
19 Dipartimento di Chimica Generale e Inorganica, Universit� di Parma, Italy.
* To whom correspondence should be addressed. E-mail:
