Scientists say they have found fossilized evidence for some of the oldest life on Earth, dating back 3.95 billion years into our planet’s history.
The research, published in Nature, was led by the University of Tokyo in Japan. The team analyzed sedimentary rocks – formed by sediments settling at the bottom of the ocean – in northern Labrador, Canada.
The groundbreaking discovery pushes the earliest date life emerged on Earth back 150 million years, as previous evidence of life dates to 3.8 billion years ago. This was a time in history when our planet was still being pounded by asteroids, known as the Late Heavy Bombardment period.
“Our discovery substantially broke the record of the earliest life on Earth,” Tsuyoshi Komiya from the University of Tokyo, a co-author of the study, told IFLScience. “This information helps the study of early life and the origin of life.”
The team discovered evidence of simple life by looking at graphite inside metasedimentary rocks that have been heated or subjected to high pressure. Studying the graphite, the researchers found evidence that it was biogenic, meaning it was produced by life. A lack of inconsistencies between the temperatures of the graphite and the surrounding rock suggests this was not a result of later contamination.
We don’t know for sure what organism was responsible, but it’s possible the graphite was produced by some sort of single-celled organism capable of photosynthesis. Complex life probably did not arise until about 800 million years ago, after photosynthetic life had oxygenated our atmosphere.
“Early life possibly had a simple morphology, indistinguishable from inorganic products,” said Komiya.