Researchers working at a sedimentary rock formation in northern Canada have uncovered evidence of early life in 3.95 billion-year-old rocks, a new study published in the journal Nature reports.
This controversial research suggests that microbial life came about right after Earth first formed. During the Eoarchaean Era — when our planet was only 500 million years old — volcanoes littered the Earth’s landscape and made the crust too hot to support tectonic activity. In addition, asteroids pounded the surface and a combination of methane and ammonia filled the atmosphere.
The idea that life emerged in such a hostile environment surprised scientists and could re-write what we know about Earth’s history. Scientists in the study first reached their new conclusion after discovering traces of biological activity locked inside badly-warped, 3.95 billion-year-old sedimentary rocks. That finding suggests life originated roughly 150 to 250 million years earlier than previously thought.
Before the new discovery, the oldest evidence of life on Earth came from 3.8-billion-year-old rocks uncovered in Greenland. However, the new traces — analyzed by researchers at the University of Tokyo — were discovered in the Saglek Block in northern Labrador, Canada, a site that dates back roughly 3.95 billion years.
The team found the evidence by both conducting a detailed geological analysis of the rocks and measuring biogenic graphite grains locked within the sediment. Then, after making sure the samples were not contaminated by rocks from other periods, they concluded the traces indicate a new timeline. While some researchers are skeptical of the data, plenty agree is could have massive implications.
“This is an excellent paper with lots of information and another definite proof that life existed back in the Eoarchean,” said Dominic Papineau, a researcher at University College London, according to Gizmodo. “I think the authors make a solid case, although it could have been further compelling by looking at the elemental and molecular compositions of the graphite and the mineral associations with the graphite.”
This new evidence is interesting because, not only could it shed light on life on Earth, but it may also help provide insights into other planets as well. If life started so quickly on Earth under such stressful conditions, then a similar process could have taken place in other parts of the universe.
“The discovery of the biogenic graphite (in Labrador) enables the geochemical study of the biogenic materials themselves, and will provide insight into early life not only on Earth but also on other planets,” the researchers noted in their study, according to National Post.