In a letter dated 1871 to his friend Joseph Dalton Hooker, Charles Darwin hypothesised that life could have originated in “a warm little pond”. Today, more than 150 years later, that hypothesis has been further confirmed thanks to a study carried out by an interdisciplinary team of Italian scientists on the island of Pantelleria, Sicily, specifically at a small thermal lake called “Bagno dell'Acqua”: This place has proved to be an ideal natural laboratory for simulating environments similar to those that may have existed billions of years ago on both Earth and Mars, offering valuable clues about the universal mechanisms of the origin of life.

The research, published in the International Journal of Molecular Sciences, was conducted by researchers from the National Research Council (CNR), the University of Tuscia, the National Institute of Astrophysics (INAF), Sapienza University of Rome, with the collaboration of the Ente Parco nazionale Isola di Pantelleria and funded by the Italian Space Agency (ASI) through the “ExoMars” and “Migliora” projects.

"The “Bagno dell'Acqua” lake stands out for its unique combination of high alkalinity, hydrothermal activity, mineralogical diversity and microbial activity. Using the mineral-rich water from the lake, we were able to synthesise RNA molecules (one of the two molecules, together with DNA, that are fundamental to life) from some of its precursors: nucleotides containing guanine, one of the four famous nitrogenous bases," says Giovanna Costanzo, molecular biologist at the Institute of Molecular Biology and Pathology of the National Research Council (CNR-IBPM). “In Pantelleria, in an environment outside the laboratory where we usually carry out our activities, we verified the possibility of conducting astrobiology experiments, exploiting the chemical and physical properties of a lake with characteristics similar to those hypothesised for primitive Earth, i.e. our planet about 4.5 billion years ago, and those detected in Martian areas of great astrobiological interest, such as the Jezero crater and the Oxia Planum region, currently considered priorities for the search for ancient life forms."

The researchers succeeded in synthesising not only RNA, but also all the nitrogenous bases present in both DNA and RNA. “In addition, components of PNA (Peptide Nucleic Acid), a potential precursor of current nucleic acids, which may have represented a bridge between genetics and metabolism, were also obtained,” explains organic chemist Raffaele Saladino of the University of Tuscia in Viterbo. “Life, therefore, could have had a common chemical origin both in the distant past of Mars and on ealry Earth.”

The Migliora project (Modeling Chemical Complexity: all'Origine di questa e di altre Vite per una visione aggiornata delle missioni spaziali - Modelling Chemical Complexity: at the Origin of this and other Lives for an updated vision of space missions) is part of a national astrobiology programme that ASI has been coordinating since 2020. 'The results of this project are a fundamental piece in the puzzle of understanding the origin of life on Earth,' emphasises Claudia Pacelli, Scientific Director of the project for ASI. 'We believe that this research will also contribute to strengthening the role of the Italian scientific community in the context of international astrobiological research.'

References:

Valentina Ubertini, Eleonora Mancin, Enrico Bruschini, Marco Ferrari, Agnese Piacentini, Stefano Fazi, Cristina Mazzoni, Bruno Mattia Bizzarri, Raffaele Saladino, Giovanna Costanzo. “The “Bagno dell’Acqua” Lake as a Novel Mars-like Analogue: Prebiotic Syntheses of PNA and RNA Building Blocks and Oligomers”, International Journal of Molecular Sciences, 2025, 26, 6952. https://doi.org/10.3390/ijms26146952