Life on Earth might have started billions of years ago on land, not in the sea, according to a new study.
A group of researchers found that the red rocks of the Pilbarra in Western Australia contain terrestrial hot spring deposits, and in them, the earliest known remnants of life on land.
Dating back 3.5 billion years, the finding (published in the journal Nature on Tuesday) moves back evidence of life on land by 580 million years. And not only that, it hints at the possibility that life on Earth began not in the ocean, as commonly thought, but on land-based hot springs. *Mind blown*
Scientists involved in the study discovered signs of the stromatolite fossils (formed by cyanobacteria) in the remains of the freshwater hot spring located in the Dresser formation area of the Pilbarra, concluding that exposed land first appeared on Earth 130 million years earlier than previously thought.
Co-author and PhD candidate Tara Djokic of the University of New South Wales (UNSW) told the ABC, “To actually find hot spring deposits is like a smoking gun for the story of a terrestrial hot spring setting for early life on the planet.”
In the past, the area was thought of as the remains of a shallow coral reef, but as co-author Van Kranendonk of UNSW told the news outlet, the fossilised remains of gas bubbles could have only been produced by microbial material. “It’s an absolute one-to-one comparison, and we’re completely convinced that this is a hot spring deposit; there can’t be anything else it can be,” he said.
“We have this incredibly delicate texture preserved, with all these shapes and fabrics and some of those include overlaps of layers that are characteristic of what we see in modern hot springs where there’s a pool and a rim that accretes out over the pool.”