Fossils are 220 million years older than any previously found, dating life on Earth to an earlier point than thought and raising questions about life on Mars
Scientists have discovered the oldest physical evidence for life on the planet in the form of fossils in Greenland rocks that formed 3.7bn years ago.
The researchers believe the structures in the rocks are stromatolites – layered formations, produced by the activity of microbes, that can be found today in extremely saline lagoons in a few locations around the world.
The new fossils are 220 million years older than any previously discovered.
Up until now the oldest stromatolites have been from Western Australia and they are roughly 3,500 million (3.5bn) years [old], said Clark Friend, an independent researcher and co-author of the research. What we are doing is pushing the discovery of life earlier in Earths history.
The discovery, says Friend, also raises questions about the possibility of life on other planets.
If we have got life at 3,700 million (3.7 bn) years on Earth, did it exist on other planets – because Mars, for example, 3,700 million years ago was wet, he said.
Writing in the journal Nature, Friend, together with a team of Australian scientists including his long-term collaborator Allen Nutman of the University of Wollongong, reveal how they discovered what they believe to be stromatolites in rocks of the Isua supracrustal belt in southwest Greenland. With the Earths known rock record only extending around 4.2bn years, the site is home to some of the worlds older rocks.