A recent study has pushed back the estimated age of the Last Universal Common Ancestor (LUCA) to around 4.2 billion years ago, several hundred million years older than previous estimates. This finding raises questions about life’s origin and suggests that it may have arisen extremely rapidly, almost as soon as our planet became habitable.
The study’s authors used deep-time genetic analysis to arrive at the new estimate. If correct, this would mean life emerged on Earth during a brief window of time after its formation, around 200 million years ago. This rapid origin of life challenges our previous understanding of the process and suggests that the development of functional components may have occurred quickly.
The findings also open up the possibility of panspermia, or the idea that life originated elsewhere in the universe and arrived on Earth via meteorites. While this hypothesis is statistically unlikely if the meteorite comes from outside the solar system, it becomes more plausible if the origin is Mars. The planet’s habitability window may have been longer than Earth’s, and Martian meteorites have already landed on our planet.
The study’s implications are significant, and scientists continue to debate the origins of life on Earth. Further research, including studying Mars alongside Earth, may provide clues to unraveling the mystery. While panspermia remains a speculative idea, it is an intriguing possibility that warrants further exploration.
Source: https://bigthink.com/hard-science/new-findings-raise-questions-about-when-and-where-life-began