Researchers analysed ice cores from a number of locations in Greenland, including Dye 3 in the south of the country. From the base of the 2km deep Dye 3 core, they were able to extract what they believe is likely to be the oldest authenticated DNA obtained to date.
By analysing these DNA samples, the researchers identified a surprising variety of plant and insect life, including species of trees such as alder, spruce, pine and members of the yew family, as well as invertebrates related to beetles, flies, spiders, butterflies and moths. The researchers believe that the samples date back to between 450,000 and 800,000 years ago.
"We have shown for the first time that southern Greenland, which is currently hidden under more than 2km of ice, was once very different to the Greenland we see today," explains Professor Eske Willerslev, a Wellcome Trust Bioarchaeology Fellow from the University of Copenhagen, who led the study."Back then, it was inhabited by a diverse array of conifer trees and insects."
The research implies that ancient forests covered southern Greenland during a period of increased global temperatures, known as an interglacial period. When temperatures fell again, the area became covered in ice. This ice sheet appears to have remained during the last interglacial period (116,000-130,000 years ago) when the temperature was 5°C warmer than today, contrary to the view currently held by scientists. Professor Dorthe Dahl-Jensen, also at the University of Copenhagen, has shown that in fact, even during this interglacial period, the ice thickness at Dye 3 would have been reduced to between 1 km to 1.5km.
"If our data is correct, then this means that the southern Greenland ice cap is more stable than previously thought," says Professor Willerslev. "This may have implications for how the ice sheets respond to global warming."
However, Professor Willerslev was keen to dismiss the idea that this meant sea levels would not rise to the levels predicted by scientific models.
"We know that during the last interglacial, sea levels rose by 5-6m, but this must have come from other sources additional to the Greenland ice cap, such as Antarctic ice. I would anticipate that as the Earth warms from man-made climate change, these sources would still contribute to a rise in sea levels."
The results also show conclusively that ancient biomolecules from the base of ice cores can be used by scientists to reconstruct the environments hidden underneath ice-covered areas and can yield insights into the climate and the ecology of communities from the distant past.
"Analysing ancient biomolecules from beneath glaciers and ice sheets is challenging due to the very low concentrations, but the information is worth the effort," says Dr Enrico Cappellini, a member of the University of York's new PALAEO Group and another of the paper's co-authors, whose work is supported by the European Commission. "Our study suggests a solution to this problem. Given that ten per cent of the Earth's terrestrial surface is covered by thick ice sheets, it could open up a world of new discoveries."
Craig Brierley | EurekAlert!
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine