Scientists Found Some Of The Oldest Evidence Of Life On Earth In South Africa

A layer of fossilized microbes that most likely lived on the floor of an ancient riverbed was discovered in South Africa. These microbes lived about 3.22 billion years ago, according to a new study published in Nature Geoscience.

Researchers from the European Institute for Marine Studies discovered the fossilized microbes on what's thought to be one of the world's oldest shorelines, in the Barberton Makhonjwa Mountains of eastern South Africa, Stefan Lalonde told Live Science. A co-author of the new study, he is a geochemist from the European Institute for Marine Studies in France.

The idea that life existed this early in Earth's history has been around for decades, but a lack of hard evidence has persisted, Hugo Beraldi Campesi, a geobiologist at the National Autonomous University of Mexico, told Live Science. He was not involved in the new research. "The problem was always the lack of hard evidence — until now," he said.

Last year, a separate team of researchers from University College London (UCL) found the remains of microorganisms in Canada that they estimated were at least 3.77 billion years old. These findings are unusual, and evidence is still scarce. But these recent discoveries shed light on a time in Earth's history when the planet could have been teeming with microscopic life.

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Researchers from the European Institute for Marine Studies have discovered fossilized microbes in the Barberton Makhonjwa Mountains of eastern South Africa, shown here. These microbes lived about 3.22 billion years ago, according to a new study. WIKUS DE WET/AFP/Getty Images

These discoveries indicate that the beginnings of life likely emerged "from hot, seafloor vents shortly after planet Earth formed," Matthew Dodd, a researcher at UCL Earth Sciences and the London Center for Nanotechnology, told CNN.

In this recent case, the fossils prove that a thick sheet of microbes once thrived in this location and that other life probably lived there as well. A ripple pattern—frozen in time—suggests that the sheets of microbes coated the bottom of a river or stream.

"This is essentially Earth's oldest riverbed," Lalonde said. "And it's already containing life."

Nitrogen atoms found in the fossils suggest that the ancient microbes consumed nitrate, which would've given them the energy to thrive. They likely lived on Earth, during the Archean eon, which lasted from 4 billion to 2.5 billion years ago.

"It confirms that terrestrial continents were fully developed," Beraldi Campesi said.

Correction: The research was about one of the oldest known organisms on land, not on Earth. Also, researcher Hugo Beraldi was not involved with the study from the European Institute for Marine Studies.