Life on Earth May Have Started Earlier
A group of scientists claims to have found new evidence suggesting complex life on Earth may have begun 1.5 billion years earlier than previously thought. Working in Gabon, the team discovered signs in rocks indicating suitable conditions for animal life 2.1 billion years ago. However, these organisms were limited to an inland sea, did not spread globally, and eventually died out. This theory diverges significantly from the conventional belief that animal life began around 635 million years ago, and not all scientists agree with the findings.
The research centers on formations found in Franceville, Gabon, which some debate as being fossils. The scientists analyzed the surrounding rock for nutrients like oxygen and phosphorus, essential for supporting life. Professor Ernest Chi Fru from Cardiff University led the international team and suggested that these early life forms resembled slime mold, a brainless single-cell organism that reproduces with spores.
Professor Graham Shields from University College London, who was not involved in the study, expressed skepticism. He acknowledged the possibility of higher nutrient levels 2.1 billion years ago but doubted that this alone could lead to the diversification needed for complex life, calling for more evidence.
Professor Chi Fru argued that his findings support ideas about life-creating processes on Earth, showing fossils and oxygen indicative of early complex organisms. He compared this to the Cambrian period, 635 million years ago, suggesting it helps us understand the origins of life.
The first hint of earlier complex life emerged about a decade ago with the discovery of the Francevillian formation. Chi Fru and colleagues claimed it contained fossils of life forms capable of movement. To bolster their theory, they analyzed sediment cores from Gabon. The rock’s chemistry suggested a “laboratory” for life created by colliding continental plates underwater, leading to volcanic activity and a nutrient-rich inland sea.
This environment, rich in oxygen and phosphorus, may have supported photosynthesis, increasing oxygen levels and enabling more complex behaviors in primitive organisms. However, the isolated nature of this environment eventually led to the organisms’ demise due to a lack of new nutrients.
PhD student Elias Rugen from the Natural History Museum, not involved in the research, agreed that significant changes in oceanic cycles occurred around this time. He acknowledged the possibility of complex life emerging 2 billion years ago but emphasized the need for more evidence to substantiate these theories.
Re-reported from the article originally published in BBC.
