2024-08-01 08:29:44
A group of scientists working in Gabon say they have found evidence deep in the rocks that 2.1 billion years ago. years, favorable environmental conditions for animals have been created. But they say these organisms were confined to the inland sea, didn’t spread around the world — and eventually went extinct.
These ideas are very different from conventional thinking – and not all scientists agree with them.
Most experts believe that animal life began around 635 million years ago. years. The research adds to the ongoing debate over whether or not the hitherto unexplained formations found in Franceville, Gabon, Africa, are actually fossils.
Scientists examined the rocks around the formations to see if they contained nutrients such as oxygen and phosphorus that could have supported life.
Professor Ernest Chi Fru of Cardiff University worked with an international team of researchers. He told the BBC that if his theory is correct, these life forms must have been similar to slimes, single-celled organisms without brains that reproduce by spores.
But Professor Graham Shields of University College London, who was not involved in the study, says he has some doubts.
“I am not against the idea that 2.1 billion years ago years, there were more nutrients, but I’m not convinced that this could have led to the diversification of complex life,” he says, adding that more evidence is needed.
Prof. Chi Fru says his work has helped prove ideas about the processes that create life on Earth.
“We’re saying, look, here are fossils, there’s oxygen, which led to the emergence of the first complex living organisms,” he says. – We see the same process as in the Cambrian period, 635 million years ago. years – this helps to justify it. It helps us ultimately understand where we all came from.”
The first hint that complex life might have appeared earlier than previously thought came about 10 years ago, when the so-called Franceville Formation was discovered. Prof. Chi Fru and his colleagues said the formation was made up of fossils that showed evidence of life that could “wriggle” and move at will. Even then, not all scientists agreed with these discoveries.
To find more evidence to support their theories, Professor Chi Fru and his team are now analyzing sediment samples taken from rock in Gabon.
The chemical composition of the rocks showed that a “laboratory” of life had been established shortly before the formation. The researchers believe that the high levels of oxygen and phosphorus were formed underwater when two continental plates collided – and this triggered volcanic activity. The collision cut off a stretch of water from the rest of the oceans, creating a “nutrient-rich shallow inland sea.”
Prof. Chi Fru says that this sheltered environment provided the right conditions for photosynthesis, resulting in plenty of oxygen in the water.
“This may have provided enough energy to allow for the increased body size and more complex behaviors that characterize the primitive, primitive animal-like life forms that we find in fossils from this period,” he says.
However, the researcher says that the isolated environment also led to the extinction of life forms – because there was a lack of new nutrients to sustain food supplies.
Elias Rugen, a postdoctoral fellow at the US Museum of Natural History who was not involved in the study, agrees with some of the findings, saying it’s clear that “the carbon, nitrogen, iron and phosphorus cycles in the oceans have been doing something a little unprecedented for this period of Earth’s history.”
“No one is saying that complex biological life could not have emerged and flourished as early as 2 billion years ago. years,” he says. But adds that more evidence is needed to support the theories.
The results of the study have been published in the scientific journal “Precambrian Research”.
BBC parents.
2024-08-01 08:29:44