Paleontologists may have just uncovered the trace fossils of the oldest creatures on Earth: 4.28 billion years old.
The oldest life
It was a time when the Moon was still freshly formed, and liquid water likely flowed on Mars. The Earth was, at best, an unfriendly and bizarre place. Yet somewhere beneath the surface, in the proximity of a hydrothermal vent close to what is today Canada, these bacteria found a way to thrive.
The fossils were discovered in the Nuvvuagittuq Supracrustal Belt (NSB) on the coast of Hudson Bay in the northern parts of Canada’s Quebec province. The supracrustal belt contains some of the world’s oldest sedimentary rocks, deposits of sand and gravel which accumulated in the earliest stages of Earth’s geological history — more than 4 billion years ago. These structures were slowly uplifted through geological processes, ultimately emerging from the sea.
“The fact we unearthed them from one of the oldest known rock formations suggests we’ve found direct evidence of one of Earth’s oldest life forms,” says University College London (UCL) Earth scientist Dominic Papineau, lead researcher on a study published today in Nature Paleontology, in a press release.
“This discovery helps us piece together the history of our planet and the remarkable life on it, and will help to identify traces of life elsewhere in the universe.”
Indeed, the idea that life on Earth emerged around hydrothermal vents (or… one hydrothermal vent?) is one of the oldest theories regarding the spawning of life on our planet, competing with panspermia — the theory that life was brought by an asteroid or some other celestial body. If this finding is confirmed, it certainly supporting the former.
“Our discovery supports the idea that life emerged from hot, seafloor vents shortly after planet Earth formed,” says Matthew Dodd, first author on the study and a UCL Ph.D. student. “This speedy appearance of life on Earth fits with other evidence of recently discovered [3.7-billion]-year-old sedimentary mounds that were shaped by microorganisms.”
Evidence and skepticism