The earliest evidence of complex life on Earth dates back 2.1 billion years, with ancient microorganisms thriving in a phosphorus-rich environment created by a volcanic collision.
For most of the planet’s first three billion years, oceans were barren due to a lack of phosphorus, essential for DNA assembly and ATP energy production. Life was slow-paced and consisted only of single-celled microbes.
However, around 2.1 billion years ago, the Congo and São Francisco continental blocks collided, unleashing underwater volcanoes that pumped phosphorus-rich fluids into a shallow inland sea now preserved in Gabon’s Francevillian sub-basin.
Cyanobacteria thrived in this environment, releasing oxygen and creating conditions that favored larger body sizes and cooperative cell assemblies. The chemical bloom raised local energy budgets, allowing for the growth of bigger bodies and complex life forms.
The discovery, led by Cardiff University geobiologist Dr. Ernest Chi Fru, provides a new episode in the evolutionary timeline, pushing the arrival of complex organisms back by 1.5 billion years.
If these fossils truly represent multicellular life, they mark a significant shift in the evolution of life on Earth, with oxygen and phosphorus playing crucial roles in the development of more complex ecosystems.
Source: https://www.earth.com/news/complex-life-on-earth-emerged-one-and-one-half-billion-years-earlier-phosphorus