‘Before Oxygen, before us’: This microbe may be the root of all life on Earth
Produced by: Manoj Kumar
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Ancient Ancestor
LUCA—the Last Universal Common Ancestor—may have lived 4.2 billion years ago, just 400 million years after Earth formed.
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Genetic Timepiece
Researchers used molecular clocks and fossil-calibrated timelines to rewind evolution and date LUCA’s emergence with precision.
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Complex Origins
LUCA wasn’t basic—it likely had DNA, ribosomes, and ATP metabolism. A cell more advanced than anyone expected.
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Early Immunity
Even at that ancient age, LUCA may have battled viruses, suggesting immune-like defenses existed from the dawn of life.
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Extreme Beginnings
Hydrothermal vents likely hosted LUCA’s world—high pressure, high heat, and chemical-rich waters fueled life’s first spark.
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Ecological Spark
LUCA’s waste was likely fuel for other microbes. These recycling interactions may mark Earth’s earliest ecosystem.
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Rapid Life
If life appeared so soon after Earth formed, it hints that biology may emerge easily on other Earth-like planets.
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Cross-Lineage Clues
Scientists used gene-tree reconciliation, tracking ancient gene swaps to reconstruct LUCA’s life with unprecedented clarity.
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Living Legacy
Though long gone, LUCA’s biological toolkit survives in every living thing today—a silent blueprint etched into life’s DNA.
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