In a remote corner of eastern Canada — polar bear country, miles from the nearest village — researchers say they may have found the “oldest evidence” of life on Earth embedded in rocks dating back billions of years.
The scientists, in findings published in the journal Nature on Wednesday, said they found graphite, a type of pure carbon, in 3.95-billion-year-old sedimentary rocks retrieved from the northern Labrador region. Geological analysis of the graphite suggested that the material had been produced by autotrophic marine microorganisms, the scientists said. Autotrophy is the ability of certain organisms ― like green plants, algae and certain bacteria ― to produce their own food from inorganic substances.
If the findings are true, the Labrador graphite would be at least 150 million years more ancient than the previous title holders of the oldest traces of life ― graphite dating back 3.7 billion years found in Greenland, and 3.8 billion years in Quebec.
As CBC News notes, the discovery implies that life may have first emerged on Earth just 500 million years or so after the planet was formed.
Study co-author Tsuyoshi Komiya, a geologist at the University of Tokyo, told LiveScience that more analysis needs to be conducted on the Labrador rock samples. Further research, he said, could provide insights into the the origin and evolution of the planet’s early life forms.