The primordial soup of the origin of life cooks at Donostia International Physics Center

It is not being prepared by any chef nor is it being served by any restaurant. The soup that cooks at the laboratory of Donostia International Physics Center (DIPC) is part of PROTOS, an ambitious scientific project with 10 million euros funding from the European Research Council through an ERC Synergy Grant and led by DIPC Ikerbasque Research Professor Juan Manuel García-Ruiz. PROTOS aims to create primitive worlds, or PROTO worlds, inside glass flasks to study, among other things, the role played by silica in that “primordial soup” that gave rise to life on Earth.

The idea of reproducing the conditions of the primitive Earth in a flask is not new; it is based on the famous experiment carried out by the scientist Stanley Miller the same year that Juan Manuel García-Ruiz was born. “It is one of the most elegant and interesting experiments in the history of science,” said García-Ruiz, when referring to this experiment which, like PROTOS, combines water, gases and electrical discharges inside a glass reactor.

García-Ruiz was a pioneer in 2021 when he decided to modify a key aspect of Miller's experiment by replacing the glass reactor by one made of Teflon, an inert material. The result was revelatory: neither the amino acids nor the nucleobases that appeared in previous experiments, and which are regarded as the fundamental building blocks of life, emerged. “It was an iconic experiment that nobody dared question. It took us years to explain that we were not questioning Miller's experiment, but instead we were incorporating the silica of the glass as a key variable in the process to form amino acids,” explained García-Ruiz.

According to García-Ruiz, atmosphere and water were not the only catalysts for life in the primordial soup. The rocks in which the soup was made also played an important role, as they contained silica and silicates.

“I have always thought that silica is fundamental in the synthesis of prebiotic compounds and with PROTOS we have gone a step further. Our results show that silica also induces the formation of biomorphic structures, or protocells, which are essential compartments for more complex reactions to take place, and eventually the emergence of life. We believe that these hollow vesicles have always been present, even in Miller's experiment, but no one had looked for them because they were thought to be a later phenomenon,” explained Professor García-Ruiz.

With García-Ruiz joining the DIPC as an Ikerbasque Research Professor, both institutions receive the PROTOS ERC Synergy Grant (SyG_2023_GA101118811), thus opening up a new research line at the DIPC. “With the arrival of PROTOS, the DIPC will be developing a state-of-the-art line of research to explore the chemical and physical processes that led to the emergence of the first living organisms. The PROTOS project is fascinating and it is a privilege to carry it out at our center,” declared the DIPC’s Director Ricardo Diez-Muiño.

As for Ikerbasque, its scientific director Fernando Cossio pointed out that “the frontier of knowledge is attracting us with growing force, proportional to the ambition of the questions posed and the projects that will allow them to be answered. Whenever doubts are resolved, new questions arise, more questions that encourage us to go on exploring. The importance of this type of project confirms that in the Basque Country we are in a position to support the leadership of cutting-edge research lines, and that the necessary conditions are in place for researchers of Juan Manuel García's caliber to place their trust in Ikerbasque and the DIPC to develop their scientific and life project”.

As regards Professor García-Ruiz, his arrival at the DIPC has allowed him to retain his position as Ad Honorem CSIC (Spanish Research Council) professor at the Andalusian Institute of Earth Sciences in Granada and build up his own laboratory on Mineral Self-organization and the Origin of Life from scratch, while pursuing another of his passions: the dissemination of science. “The reception at the DIPC has been excellent. We have the support of the Basque Government through Ikerbasque, we are building a state-of-the-art laboratory to continue driving forward our research, and I have been able to develop dissemination projects together with the DIPC. I am delighted,” said García-Ruiz.

A double date with dissemination: Giant Crystals and ExoMars

Next week, on Tuesday 11 March in fact, there will be a screening of the documentary The Mystery of the Giant Crystals, followed by a discussion with García-Ruiz together with the film's director Javier Trueba. This screening is an opportunity to learn about García-Ruiz's extensive career as a crystallographer and to join him on a journey to the depths of the Earth to try to explain one of the great mysteries of the mineral world: the formation of giant gypsum crystals.

On Wednesday 12 March, Jorge Vago, the European Space Agency's (ESA) ExoMars Project Scientist, will be giving a talk entitled Searching for life on Mars with the Rosalind Franklin rover, a space explorer that will be sent to the red planet in 2028 to explore the Martian subsoil in search of biological evidence. The gathering and subsequent discussion will be led by García-Ruiz, who also collaborates in the ExoMars mission as an “interdisciplinary scientist.” This means that PROTOS will have direct access to the data obtained by the Rosalind Franklin rover.

Early results of PROTOS

PROTOS is an international collaboration led by the Ikerbasque Research Professor Juan Manuel García-Ruiz; it has the participation of the DIPC as project coordinator, the University of Bremen, the Naturalis Biodiversity Center of Leiden, the Leibniz University of Hannover, the Geo-Ocean lab of the CNRS, the Andalusian Earth Sciences Institute (IACT-CSIC) and the Génie Chimique lab of the National Polytechnic Institute of Toulouse.

The early results of PROTOS were published recently in the journal Proceedings of the National Academy of Science (PNAS). In this study, García-Ruiz and his team provide new evidence indicating that silica induced the formation of biomorphic structures, which García-Ruiz defines as “protocells”.

The images of these protocells circled the globe. According to García-Ruiz, the presence of these hollow vesicles in the PROTOS flasks suggests that the conditions for life were present on Earth much earlier than previously thought, in the geological period known as the Hadean, which began with the formation of our planet 4.6 billion years ago and ended 4 billion years ago.

“The PROTOS results indicate that all the basic ingredients of life were there from the start. This means that life is the result of a chemical evolution that has taken millions of years, clumsy, slow, but very stubborn. There is no divine spark, there is no intelligent design, there are just a load of truncated trees next to the tree of life.”

As the PROTOS experiments progress, García-Ruiz warns: “The difference between the living and the non-living is becoming increasingly blurred. We are far from understanding the complete sequence that allowed the transition to take place from simple molecules to living organisms, but we will go on cooking to see what happens.”

The PROTOS kitchen

The experiments in the PROTOS project are being carried out in the Mineral Self-Organization and Origin of Life Laboratory of Professor Juan Manuel García-Ruiz in Donostia/San Sebastian.

Amid quartz, Teflon and borosilicate reactors, García-Ruiz works side by side with the researchers Christian Jenewein and Borja Aparicio. Andrés Blanco, the manager of the PROTOS project, completes the team.

On the sides of the flasks, a brown layer can be seen; it is the result of electrical discharges and ultraviolet radiation, and is where García-Ruiz and his team have already been able to identify up to 17 types of amino acids and the 5 nucleobases that comprise DNA.

A closer look reveals small dark particles on the surface of the soup. “Those things floating there are the hollow vesicles that we call protocells. They are small compartments that allow the prebiotic compounds to react with each other and evolve towards greater complexity,” explained García-Ruiz.

On the walls of these vesicles, García-Ruiz's team have found hydrocyanic acid polymers, a simple molecule made up of one hydrogen, one carbon and one nitrogen atom. “Several studies suggest that everything can be created from these polymers, including life,” said García-Ruiz.

Juan Manuel García-Ruiz (Seville, 1953) is an Ikerbasque Research Professor at the DIPC and is leading the ambitious European PROTOS project, funded by the European Research Council through an ERC Synergy Grant, to study the role of silica in the origin of life on Earth. His main field of research is self-organization phenomena in biological and geological structures, with implications ranging from the origin of life to the synthesis of new materials. He is an internationally recognized expert in mineral genesis, and stands out for his studies on the formation of giant crystals and the crystallization of drugs and proteins. He has directed various space crystallization projects in which he has coordinated more than 30 European and Japanese laboratories, and holds several licensed patents. He is also an activist committed to science culture and has promoted initiatives such as the  School Crystallization Competition since 2009, an innovative educational tool in which more than 15,000 students between the ages of 12 and 16 from all over Spain participate every year and which has expanded to several countries in the Americas and, starting this year, to Kenya, Africa. He is also co-author of the show The Crystallization of Dance, an original production that emerged out of the dialogue between the scientist Juan Manuel García-Ruiz and the dancer and choreographer Vanesa Aibar, and which will be presented this year at the Victoria Eugenia Theatre in Donostia / San Sebastian.