Researchers from Heinrich Heine University Düsseldorf and international collaborators have revealed that life on Earth likely began not once, but twice. Their study indicates that early forms of bacteria and archaea independently developed the ability to live freely, tracing back to a common genetic background but distinct metabolic evolution.
- Life may have originated twice independently in bacteria and archaea
- Early metabolism combined enzymes with metal catalysts from hydrothermal vents
- Separately evolved enzymes replaced inorganic catalysts over time
What happened
An international research team led by biologists at Heinrich Heine University Düsseldorf explored the earliest stages of cellular life by analyzing genomes, protein structures, and chemical reactions crucial for metabolism. They discovered that the two main domains of life, bacteria and archaea, likely evolved free-living abilities independently after sharing a common ancestor with a partial enzymatic toolkit.
Their findings, published in Science Advances, highlight that the last universal common ancestor (LUCA) possessed enzymes for only about half of the metabolic reactions required for life. The other half were driven by metallic catalysts naturally found in early Earth environments such as hydrothermal vents, indicating a hybrid system of metabolic evolution bridging inorganic chemistry and biology.
Why it feels good
This breakthrough challenges the longstanding assumption that all modern life descended from a single free-living ancestor species. Instead, it introduces a rich complexity to our understanding of life’s origins, showing evolution's creative adaptability even at molecular levels.
It is inspiring to realize that life’s earliest forms used metals from the environment as helpers before enzymes fully took over, showcasing nature’s efficient use of available resources. This story of life’s dual origins invites us to appreciate the diverse pathways evolution explores, deepening our connection to the ancient world.
What to enjoy or watch next
For those fascinated by the origins of life and evolutionary biology, the full study offers a detailed reconstruction of four key stages in early metabolic evolution, tracing how biochemical catalysis shifted from metals to enzymes within different life domains. It opens new avenues for research in astrobiology and synthetic biology.
Additionally, exploring documentaries and lectures on the role of hydrothermal vents and early Earth environments can provide rich context. Witnessing how modern microbes thrive in such extreme habitats today helps bring this ancient story to life.