Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ 2-billion-year-old scavengers could be the earliest evidence of a mobile lifestyle

2-billion-year-old scavengers could be the earliest evidence of a mobile lifestyle

Image: A. El Albani and A. Mazurie / IC2MP CNRS – Université de Poitiers

The open discovery of fossil traces of 2.1 billion years of etching in a sedimentary rock repels the earliest evidence for a self-propelled movement of an organism on Earth with a huge 1.5 billion years. capacity for self-propulsion at least 2.1 billion years ago and not 570 million years ago, as previous studies suggest. The evidence of this apparent movement, also known as mobility, is presented in the form of small petrified winding signs embedded in the ancient sedimentary rocks. The X-ray image reveals tube-like structures embedded in the sedimentary rock.

Image: A. El Albani and A. Mazurier / IC2MP CNRS – University of Pueblo

In 2010 the leading author of the new study, Abderrazak El Albani of the CNRS-Université de Poitiers, discovered the earliest evidence of a complex multi-cellular life in the Francevillian basin in the Haut-Ogooué province of Gabon in Central Africa. Dated at 2.1 billion years, the fossils were 1.5 billion years older than the previous 600 million years ago. This ancient life, suggested by the authors, lived in shallow marine environments with sufficient access to oxygen

New fossils found also in the Basin of France suggest that some forms of this ancient life have developed the ability to move through organic- rich mud on this shallow seabed. According to the new study, petrified cloud traces found in these rocks are the tunnels left by these primitive creatures as they roll in search of nutrients. If confirmed, this would be the earliest evidence of mobility in eukaryotic life, ie. animal forms with complex cells and a clearly defined nucleus. "Gallery [of the x-ray images] are spectacular, absolutely amazing!" "But credit really has to go in the quality of these rocks, which are able to exclusively keep the movement of primitive organisms." El Albani and his colleagues used chemical analysis, scanning electron microscopy and X-ray computer micrographs, the latter of which allowed the crystal clear 3D perspective of those enclosed in rock curls. String strings, of which 80 were found, were about 6 millimeters wide and stretched to a maximum length of 170 millimeters. Some of these obvious tunnels intertwine, stretching vertically and horizontally. Chemical analysis shows that the characteristics are the result of biological rather than geological processes and occur at the same time as the sludge forms. Organic matter in the rock "can be either a body that decomposes there or a mucus left by the body like a snail's path," El Albani explains in the statement. These features are located near fossilized microbubbles (layered sheets of fossilized microorganisms). The authors suggest that apparently mobile eukaryotes move around in the dirt in search of nutrients produced by the cyanobacteria responsible for microbial mats. It is important that at that time the Earth is already rich in oxygen, which makes the emergence of a complex life an obvious opportunity.

Amazingly, the tunnels were not formed by one man, but rather by mass gathering, according to the new study. These primitive eukaryotes, called "Gabonites" by the authors, unite together massively shaping the shape of a bowl. This allows them to move through the mud – both in vertical and in the horizontal directions – in search of food and areas rich in oxygen, similar to how modern colonial amaebies do. Technically speaking, these beings were mobile, but they have achieved their mobility through collective group action, according to the new study. an important evolutionary precursor to the moving life. After this period of Earth's history, a great period of ice on Earth caused a sharp drop in oxygen levels, making the life of the alleged Gabonita extremely difficult, if not impossible. They could be destroyed, and the agility to return to another species many millions of years later. Either managed to survive, setting the foundations of a critical evolutionary adaptation.

Or they do not exist at all. Speaking to The Guardian, Graham Shields of the University College London said the tunnels look organic by nature, but the evidence provided does not make it clear that mobile life is included. Structures, he said, may be remnants of microbial mats or tube-like creatures known as Grypania. Shields said he did not "see much evidence of mobility … except the superficial resemblance to paths or holes." Hence, other researchers should look at the samples themselves to confirm the findings while continuing to search for more fossils. If confirmed, however, this discovery means that complex life has arisen relatively early in Earth's history and does not waste time on developing means of self-propulsion. The primitive life seemed to be eager to leave.

[Proceedings of the National Academy of Sciences]

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