A group of scientists has discovered a “lost world” of primitive ancestors in billion-year-old rocks

At least 1.6 billion years ago, microscopic organisms lived in waterways whose molecular fossils have been found in rocks from that time and could be the earliest traces of our lineage.

discover this microscopic “lost world”being published today natureAnd It could change the understanding of our early ancestors.

All organisms with eukaryotic cells (those in animals, plants, and fungi, with DNA surrounded by a membrane) They have a first common ancestor known as LECAwhich lived 1.2 billion years ago, but must have been preceded by other forms of eukaryotes.

a group of Australian, French and German researchers discovered a large number of protosteroids in rocks from the mid-Proterozoic era (2,500 million to 542 million years ago), primitive compounds hitherto unnoticed as fossil witnesses of primitive life.

Vital sign signatures refer to a file The existence of a whole series of organisms unknown until now that dominated complex life on Earth and would have lived at least a billion years before the emergence of any animal or plant.

The existence of these microscopic organisms that are part of eukaryotic organisms was discovered by a team led by Jochen Brooks of the Australian National University (AUN), which are generically termed “protosterol organisms”.

“Molecular remains of protosterols discovered in rocks 1.6 billion years old appear to be the oldest traces of our lineage: they lived even before LECA.”Another signatory, Benjamin Nittersheim, of the University of Bremen (Germany), noted.

These creatures, which thrived from about 1.6 billion years ago to about 800 million years ago, were abundant in marine ecosystems around the world and likely shaped ecosystems for most of Earth’s history.

Although it is not known what they looked like, Brooks noted in a statement from his university, that they would have been more complex and possibly larger than bacteria: We think they may have been Earth’s first predators, hunting and eating bacteria..

They differed from complex eukaryotes as we know them (animals, plants and algae) in their cellular structure and possibly in their metabolism, which were adapted to a world with much less oxygen in the atmosphere than it does today, according to the center. Earth Science Center (GFZ).

It is also not known when They went out Exactly these ancient organisms, though they refer to the Tonic period, when more advanced eukaryotic organisms, such as fungi and algae, began to flourish.

“Just as the dinosaurs had to die out in order for our mammalian ancestors to become large and plentiful, protosterol organisms probably had to go extinct a billion years ago to make way for modern eukaryotes,” Brooks said.

To make this discovery, the researchers studied fossil lipid particles, known as protosteroids, found inside a 1.6 billion-year-old sedimentary rock from the mid-Proterozoic that formed on the ocean floor near Australia.

The molecules have a primitive chemical structure that suggests complex primitive organisms that evolved before LECA and have since become extinct. Without these biomarkers “we would never have known that protosterol organisms existed—scientists have overlooked these molecules for four decades because they don’t fit into typical molecular research pictures,” according to Nettersheim.

But once they knew what they were looking for, they found that dozens of other rocks, mined from billion-year-old streams around the world, “also secrete similar fossil particles.”

Nobel Prize in Medicine in 1958 Konrad Bloch predictedin 1994, the existence of this type of primitive molecule, so these results prove it.

However, it was considered that these primitive intermediate particles would never be found because they could not survive in the geological record, although this research now indicates that this is not the case and suggests that the remains of protosteroids may persist in rocks for more than billion years.

(with information from EFE)

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