The discovery of the Last Universal Common Ancestor (LUCA) is rewriting our understanding of life’s origins on Earth. According to a recent study published in Nature Ecology & Evolution, researchers believe that LUCA emerged around 4 billion years ago, hundreds of millions of years earlier than previously estimated.
The study, led by Edmund Moody, analyzed ancient genetic markers found across all living organisms to reconstruct the essential genes carried by LUCA. These markers suggest that LUCA was a simple, single-celled organism that thrived in extreme environments, likely near hydrothermal vents deep in the ocean.
The researchers used genomic analysis to estimate the rate of genetic mutations over billions of years and refined their models to push LUCA’s origins back significantly. The study identified 355 genes believed to have been present in LUCA, indicating that it was an anaerobic, autotrophic organism that produced its own energy from hydrogen and carbon dioxide.
The implications of this discovery are far-reaching. It supports the “life everywhere” hypothesis, suggesting that if the right conditions exist, life will inevitably arise. This strengthens the argument that microbial life might exist on Mars, Europa, or Titan.
The revised timeline for LUCA also raises hopes for finding biosignatures – chemical markers of life – on exoplanets. With this new understanding of life’s origins, scientists may be closer to discovering signs of life beyond Earth.
Source: https://dailygalaxy.com/2025/03/luca-is-much-older-than-scientists-thought