Evidence of a complex life sanctuary 2.1 billion years ago

Jul 29. () –

Until now, scientists widely accepted that animals first appeared on Earth. 635 million years ago.

But an international team, led by Cardiff University, has discovered evidence of a much older closed ecosystem in the Franceville basin near Gabon, on the Atlantic coast of central Africa, more than 1.5 billion years ago.

Their study, presented at Precambrian Research, describes a unique episode of submarine volcanic activity after the collision of two continents, which created a nutrient-rich “laboratory” for the first experiments in complex biological evolution.

Dr Ernest Chi Fru, lead author of the paper and a professor at Cardiff University’s School of Earth and Environmental Sciences, said it’s a statement“The availability of phosphorus in the environment is thought to be a key component in the evolution of life on Earth, especially in the transition from simple unicellular organisms to complex organisms such as animals and plants.”

Scientists have widely debated the validity of large fossils of macroorganisms from this period.which are the oldest of their type in the geological record.

But the Cardiff-led team identified a link between environmental change and nutrient enrichment before its onsetwhich could have triggered its evolution.

UNUSUALLY LARGE FOSSILS

The team’s geochemical analysis of marine sedimentary rocks deposited 2.1 billion years ago sheds new light on this much-discussed body of unusually large fossils from the Francevillian Basin.

Dr Chi Fru added: “We believe that submarine volcanoes, which followed the collision and suturing of the Congo and São Francisco cratons into a larger body, further restricted and even cut off this section of water from the global ocean. to create a nutrient-rich shallow inland marine sea.

“This created a localized environment where cyanobacterial photosynthesis was abundant for an extended period of time, leading to oxygenation of the local seawater and the generation of a large food resource.

“This would have provided enough energy to promote the increase in body size and more complex behavior seen in simple primitive animal-like life forms, “such as those found in fossils from this period.”

LIMITED SPACE

However, the restricted nature of this body of water, coupled with the hostile conditions that existed beyond the boundaries of this environment for billions of years afterward, probably prevented these enigmatic life forms from becoming established globallyresearchers say.

Their study suggests that these observations may indicate a two-stage evolution of complex life on Earth.

The first step followed the first major increase in atmospheric oxygen content 2.1 billion years ago and the second step followed a second increase in atmospheric oxygen levels about 1.5 billion years later.