“New Method Reveals Earth’s Oldest Traces of Life”
Scientists have uncovered some of the earliest signs of life on Earth using a breakthrough technique that identifies chemical “fingerprints” left behind by ancient organisms. This new method, powered by machine learning, has spotted biological traces in rocks as old as 3.3 billion years, offering the strongest evidence yet of Earth’s primordial life and opening new possibilities in the search for life beyond our planet.
Researchers studying rocks from South Africa found molecular clues of early microbes, including signs of oxygen-producing photosynthesis dating back 2.5 billion years. These findings not only push the timeline of photosynthetic life hundreds of millions of years earlier but also help scientists understand how Earth’s atmosphere slowly filled with oxygen, paving the way for complex life.
The method works by teaching a machine-learning system to separate organic molecules created by living organisms from those formed by non-living processes with over 90% accuracy. According to the research team, the human eye might see only confusing molecular “peaks,” but the algorithm uncovers hidden patterns that once belonged to life.
Robert Hazen, mineralogist and astrobiologist at the Carnegie Institution for Science, called the results a “paradigm shift,” explaining that this technology can recognize the “whispers of ancient life” even after all original biomolecules have broken down into tiny carbon fragments.
Until now, scientists searching for Earth’s earliest life mostly depended on rare fossils like 3.5 billion year old stromatolites found in Australia and South Africa. But fossil evidence is extremely limited, making chemical traces an essential and now more powerful tool.
The study reveals that signs of life can be identified in rocks twice as old as previously possible. It can even distinguish between different kinds of life, including photosynthetic organisms.
Beyond Earth, this method could guide future missions to Mars, Enceladus, Titan, or Europa. NASA has already supported further development of the technique, hoping it may detect life in samples collected by rovers or in plumes of organic material on distant moons.
Researchers believe this tool may one day confirm whether life ever existed elsewhere in the solar system or perhaps still exists today.
