The origins of life on Earth

Humans have always wondered about the origin of life on Earth. In a letter to Joseph Dalton Hooker dated 1844, Charles Darwin wrote that life could have evolved in "some warm little pond", the famous "primordial broth". Since then, many hypotheses have been proposed and many studies have been conducted to understand – and perhaps try to recreate – the conditions that, about four billion years ago, sparked life on our planet.

Now, a study coordinated by the University of Trento, that a few weeks ago appeared on the cover of PNAS, the peer reviewed journal of the US National Academy of Sciences, contributes significantly to the subject.

"Our goal – says Silvia Holler, researcher at UniTrento and principal investigator of the study – was to explore new directions to understand how life on Earth began. In particular, we were interested in exploring the transition from an inorganic and lifeless planet to an organic, rich and living planet."

This effort required the collaboration of researchers from different disciplines, such as biochemistry, with Holler herself and of Richard J. G. Löffler, Federica Casiraghi and Martin M. Hanczyc of the Cibio Department of the University of Trento; astrobiology, the area of expertise of Stuart Bartlett of the California Institute of Technology, and geology, with Claro Ignacio Sainz Diaz and Julyan H. E. Cartwright of the University of Granada.

The researchers recreated the conditions that may have led to the development of life in "hydrothermal vents", hot springs fed by underwater volcanoes. The team of scientists established that the inorganic structures that can be found in this environment can incorporate organic molecules to form new hybrid organic-inorganic structures. These can then support and facilitate the formation of primitive cell-like membranes, the structures that make life possible.

"Our study opens many research opportunities – continues Holler. Larger compound libraries could be tested to create inorganic structures and new organic compounds to interact with them. Scientists could also examine other factors and assess the stability of protocells at different temperatures or pH conditions. The possible applications are many and range from recreating life in the future on other planets, to the use of protocells to improve the effectiveness and accuracy of drugs in the human body. We have opened the way, there is a long way to go but the research is very promising."

The article "Hybrid organic–inorganic structures trigger the formation of primitive cell-like compartments" is available in open access at https://www.pnas.org/doi/10.1073/pnas.2300491120.