Why do some scientists believe that life on Earth is older than previously thought?

The research contributes to a debate that remains unclear today about whether the formations found in Franceville, Gabon, are fossils or not.

Scientists examined rocks around the formations to see if there was evidence of materials such as oxygen and phosphorus, which help support life.

Professor Ernest Che Frue of Cardiff University worked with an international team of scientists.

He told the BBC that if his theory was correct, the organisms would look like slime mould – a single-celled organism that reproduces using spores.

But Graham Shields, a professor at University College London who was not involved in the research, said they had some doubts about the work.

“I’m not against the idea of ​​high nutrient availability 2.1 billion years ago, but I’m not convinced that this could have led to diversification into complex life,” he says, suggesting more evidence is needed.

Chi Fru says his work helps prove ideas about the processes that create life on Earth.

“We say, ‘Look, there are fossils here, there is oxygen, and this is what triggered the emergence of the first complex organisms,'” he says.

“We see the same process that was at work in the Cambrian, 635 million years ago – and it (the research) supports that idea. It ultimately helps us understand where we all come from.”

The first sign that complex life may have begun earlier than previously thought came ten years ago with the discovery of the so-called Franceville Formation.

The formation consists of fossils that indicate evidence of an organism that could move from side to side on its own, Chi Fru and colleagues say.

The results were not accepted by all scientists.

To find more evidence, Che Fro and his team analyzed fragments of sediment drilled into the rock in Gabon.

The chemical composition of the rocks shows evidence of the creation of a “laboratory” for life before the first formation appeared.

They believe the high levels of oxygen and phosphorus were caused by the collision of two continental plates underwater, which led to volcanic activity.

The collision separated part of the water from the rest of the ocean, creating a “shallow, nutrient-rich inland sea.”

This protected environment, Chi Fru says, was able to allow photosynthesis, generating large amounts of oxygen in the water.

“This could have provided enough energy to fuel the growth in body size and more complex behavior seen in simple, primitive organisms such as those in fossils from this period,” he says.

But he says the isolated environment also led to the disappearance of this type of life, because there were not enough new nutrients to serve as food.

PhD student Elias Rogan of the Natural History Museum in London, who was not involved in the research, said he agreed with some of the study’s conclusions. “It’s clear that the carbon, nitrogen, iron and phosphorus cycles were doing something that was quite unprecedented at this point in Earth’s history,” he said.

“There is nothing to say that complex forms of biological life could not have emerged and flourished two billion years ago,” he says, but stresses that more evidence is needed to support these theories.

The results were published in the scientific journal Precambrian Research.