Although the original molecules of life or the creation of oxygen through photosynthesis no longer exist, a combination of advanced chemical analysis and I.A made it possible to find characteristic chemical fragments of life in rocks aged from 3.3 billion years.
Usage chemical methods advanced and artificial intelligence allowed American scientists to detect signs of life for the first time in Thierry does 3.3 billion yearstechnologies that could revolutionize the search for traces of life Martha and on rocky moons like Europa, according to a study published this Monday in the journal Science Proceedings of the National Academy of Sciences (PNAS).
Using these methods, scientists from Carnegie Institution for Scienceand several related universities and institutes have also been able to detect molecular signs of the existence of ago 2.5 billion years of oxygen production through photosynthesis, 800 million years earlier than previously thought.
To make these discoveries, scientists used modern chemical analysis, pyrolysis combined with gas chromatography and mass spectrometry (Py-GC-MS), to analyze more than 400 samples of all types of objects: from meteorites and sediments up to 3 billion years old to modern plants and animals.
Based on the data they received, they trained an artificial intelligence (AI) system capable of distinguishing biological from non-biological matter with up to 98% accuracy.
Like pieces of a puzzle
Although the primordial molecules of life or the creation of oxygen through photosynthesis no longer exist, a combination of advanced chemical analysis and artificial intelligence has made it possible to find chemical fragments characteristic of life in rocks as old as 3.3 billion years.
Doctor Robert Hazensenior researcher named after Carnegie Institution for Scienceexplained in a statement that “it’s like showing a computer thousands of puzzle pieces and asking it to tell you whether the original image was a flower or a meteorite.”
“Instead of focusing on individual molecules, we’re looking for chemical patterns, and these patterns can also be found somewhere in the universe. Our results show that ancient life doesn’t just leave behind fossils; it leaves a chemical “echo”. Thanks to machine learning, we can reliably interpret these echoes for the first time,” he concluded.
Thanks to the same technique, scientists at the Carnegie Institution for Science were able to anticipate the emergence of photosynthesis, the main process for the emergence of complex organisms, by 800 million years.
Rare and controversial finds
So far, scientists have only been able to find reliable chemical signs of life in rocks up to 1.7 billion years old, doubling the maximum age at which life can be detected using this method.
Lacking chemical evidence, paleobiologists rely primarily on fossil organisms, including microscopic fossils of cells and filaments, as well as the mineralized remains of cellular structures, to determine the existence of life on early Earth. But this evidence is few and sometimes contradictory.
For example, in 1993, scientists discovered in rocks in Australia what they believed to be the oldest microfossils on the planet, which are about 3.46 billion years old, although recent research has shown that their origin is chemical rather than biological.
Stromatolites, structures formed by microbial mats (biofilms) that hold sediment, have also been found in Australia and are estimated to be 3.48 billion years old.
But the reality is that the vast majority of ancient rocks do not preserve microfossils or biomolecules because they have been altered in a way that breaks them into countless fragments that until now have been too small and too common to determine their biological origin.
Dr. Michael Wong, another of the study’s authors, explained that understanding when photosynthesis appeared helps to understand how the planet became enriched with oxygen, which allowed complex life and ultimately humans to appear.
“This research could change the way we look for ancient life on Earth and in other worlds. In the future, we plan to analyze such materials as anoxygenic photosynthetic bacteria, possible analogues of extraterrestrial organisms. This is a very powerful new tool for astrobiology,” he added.
