Prebiotic Chemistry and Physics of Complex Systems Group

Line coordinator

Molecular Evolution Department
This group fundamentally addresses the study of issues related to the origins and evolution of life on Earth and molecular complexity in other planetary environments of the Solar System from two complementary perspectives, prebiotic chemistry and the physics of complex systems.
Credit illustration: María Lamprecht Grandío

Group description

This research group fundamentally addresses the study of issues related to the origins and evolution of life on Earth, as well as questions related to the increase of molecular complexity and habitability of other planetary environments in the Solar System, from a fully transdisciplinary perspective. We consider a connection between disciplines whose complementarity in the context of astrobiology has not been sufficiently developed to date, such as prebiotic chemistry, surface physical chemistry, non-equilibrium thermodynamics, and complexity theory. Our experimental tools range from experimental work simulating early Earth conditions to planetary solar system environments, paying special attention to aqueous interfaces and organic-mineral interactions under a controlled atmosphere. The theoretical work is based on the one hand on the mathematical modelling of complex processes, making use of tools from statistical mechanics, complex network theory and game theory, and on the other hand on computational work supported by the use of real data.

Overall objectives

  • Studying those critical aspects that may have led to the emergence of primordial biochemistry, such as the increase in molecular complexity, the generation of macromolecular systems with catalytic capacity, the development of protometabolic systems, the origin of chiral symmetry breaking, or biomolecules self-organising on surfaces.

  • Analysing the origin and evolution of life as complex and emergent processes, making use of complexity theory and complex networks.

We are particularly interested in prebiotic chemistry, which comprises all the natural physico-chemical processes that take place within a planetary environment, from its formation until the emergence of the first self-replicating system in which Darwinian selection processes began to work. In addition, we focus on the study of the origin and evolution of the physical, chemical and biological complexity that has characterised life from its origin to the present day.

We are trying to address some important unresolved issues. These include:

  • The generation of organic molecules from very simple precursors such as CH4 or HCN.

  • The production of biomonomers such as amino acids, nucleic bases or sugars under potential prebiotic conditions.

  • The synthesis of oligomeric systems and macromolecular systems with catalytic and/or informational properties.

  • The origin of the homochirality of current bio-organic compounds.

  • The study of the interaction, reactivity and preservation of simple biomolecules on mineral surfaces and their implications for prebiotic chemistry and planetary exploration.

  • Molecular characterisation and the effect of physicochemical parameters in planetary environments simulated in planetary simulation chambers.

  • The origin of complexity at different evolutionary stages and at different scales on the long path from the creation of life’s basic molecular building blocks in the interstellar medium and later on the early Earth to the complex interaction between organisms in today’s biosphere.

Detailed objectives

  1. Laboratory of Prebiotic Chemistry (coordinator: Marta Ruiz Bermejo).

  2. Prebiotic chemistry on surfaces: Interaction, reactivity and catalysis of biomolecules on mineral surfaces (coordinator: Eva Mateo-Marti).

  3. Theoretical aspects of prebiotic chemistry and the origin of biological homochirality (coordinator: David Hochberg).

  4. Study of the origin and evolution of life from the perspective of complexity theory and network science (Complexity and Astrobiology Group, coordinator: Jacobo Aguirre).

1. Laboratory of Prebiotic Chemistry (coordinator: Marta Ruiz Bermejo)
Studying the processes of molecular complexity building up from very simple molecules and their subsequent chemical evolution is key to understanding the mechanisms that may have led to the emergence of life on Earth. From a chemical point of view, the origin of life is a gigantic problem of retrosynthesis. Based on these ideas, in the Laboratory of Prebiotic Chemistry we synthesise complex organic mixtures, mainly from gases and saline aqueous solutions. In parallel, we also generate macromolecular systems by thermal activation of certain molecules considered to be prebiotic. In this type of experiments, we recreate potential physico-chemical conditions of the early Earth, but also of other planetary environments in the solar system. The key molecules in our studies on chemical evolution are CH4, HCN (and its soluble and insoluble salts such as NaCN and Prussian Blue) and the tetramer of the latter molecule, diaminomaleonitrile (DAMN). The characteristics of the organic mixtures obtained from them are directly dependent on the synthesis conditions, which favour the generation of some molecules over others or the production of insoluble macromolecular systems over soluble oligomers. In the vast majority of our experiments, water plays a fundamental role. Specifically, we simulate hydrothermal system conditions and study the effect of aqueous interfaces (air-water and ice-liquid water) as these significantly modify the nature of the final products. On the other hand, we also carry out studies on the influence of minerals in this type of reactions in aqueous solution. Thus, in order to understand how it was/is possible to generate a primordial biochemistry, our methodology is focused on:
  • Synthesising complex mixtures from prebiotic precursors such as CH4, HCN and their derivatives.
  • Analysing by chromatographic techniques (GC-MS and HPLC) the reaction crudes for the identification of biomonomers such as amino acids, nucleic bases and sugars, as well as cofactors, carboxylic acids or non-canonical bases.

  • Separating, purifying and structurally characterising the soluble and insoluble fractions from the reaction mixtures by using spectroscopic, analytical and microscopic techniques (elemental analysis, NMR, SEM, TGA,…).

  • Identifying the reaction mechanisms of these complex processes and how the reaction conditions are able to modify them.

  • Searching for possible components of protometabolic systems and detecting oscillating processes in our systems of high molecular complexity.

  • Studying the catalytic and re-dox properties of the products obtained.

  • Detecting and producing vesicles under potential prebiotic conditions.

2. Prebiotic chemistry on surfaces: Interaction, reactivity and catalysis of biomolecules on mineral surfaces (coordinator: Eva Mateo-Marti)
We aim to understand the guidelines governing molecular adsorption on surfaces, control biomolecule/mineral interaction processes and learn which conditions and chemical species were most favourable for the development of prebiotic chemistry and catalysis on mineral surfaces at the origin of life. To this end, we study and characterise the adsorption processes and chemical reactivity of biomolecules on metallic and mineral surfaces, using advanced surface characterisation techniques. A second objective is to study the role of mineral surfaces in catalysing the formation of prebiotic organic compounds, as a possible source of energy and catalysts in the early stages of formation of complex organic molecules. To study, therefore, how surfaces can play a crucial role in catalysing reactions of such simple molecules in prebiotic processes. These investigations are carried out experimentally in the ultra-high vacuum system: spectroscopies and microscopies on surfaces (SMS) and in the simulation chamber for planetary atmospheres and surfaces (PASC), equipment located in the planetary simulation laboratory at CAB. Such studies contribute to the understanding of molecular chemical reactivity and the role minerals may have played in prebiotic chemistry and planetary exploration. To this end, we focus our research on:
  • The dosing and adsorption of amino acids and single molecules on mineral surfaces under ultra-high vacuum conditions and planetary simulation.

  • Physico-chemical characterisation and reactivity of biomolecule/surface interaction by surface spectroscopy (XPS, IR and Raman).

  • The study of catalysis and/or preservation of molecules on mineral surfaces under planetary simulation conditions.

3. Theoretical aspects of prebiotic chemistry and the origin of biological homochirality (Coordinator: David Hochberg)

The chemistry of life as we know it is based on an exceptional asymmetry. Namely: a molecule whose geometric structure is not identical to its mirror image has “chirality”. The mirror-image structures of a chiral molecule are called enantiomers. Just as we distinguish the right hand from the left hand, the two molecular structures related by their mirror image are identified as the L-enantiomer (from “levo”) and the D-enantiomer (from “dextro”). Amino acids, the building blocks of proteins, and deoxyribose in DNA, are chiral molecules. According to Francis Crick, “the first great unifying principle of biochemistry is the fact that all key molecules have the same chirality (“handedness”) in all organisms.” This property is known as biological homochirality. This biochemical asymmetry was discovered by Louis Pasteur in 1857. Almost 170 years later, its origin remains an enigma and has given rise to an exciting area of active research that benefits from the interplay between chemistry and physics.

To solve this problem, we focus our work on the following objectives:

  • The General Evolution Criterion and the origin of biological homochirality. Chemical evolution towards biochemistry and the first primitive living beings involves non-equilibrium physico-chemical processes that dissipate energy to the environment. Theorems of non-equilibrium thermodynamics determine how this dissipation should evolve over time in such systems, giving us an important quantitative window into the dynamics of chemical evolution. We study prebiotic chemical networks that give rise to homochirality and the role played by the General Evolution Criterion.

  • Top-down transfer of chirality in molecular self-assembly by 3D hydrodynamic vortices. The net vorticity in sectional secondary flows in reactors with helical geometry is transferred to a net chirality at the molecular level during self-assembly in these vortices. We use numerical simulation of flow fields as a function of reactors with different geometries, and the solution of reaction-diffusion-advection equations.

  • Theoretical aspects of prebiotic chemistry and chiral amplification. We study self-catalytic reaction systems, self-replicating chemical systems and systems leading to spontaneous chiral symmetry breaking, as precursors to the origin of biological homochirality. We employ reaction networks in different architectures and study their dynamical stability properties, their critical properties, the role of intrinsic and extrinsic noise and fluctuations, and their spatio-temporal evolution. Other topics we address are the conditions imposed by the thermodynamics of systems far from equilibrium and the entropic aspects of chiral symmetry breaking in molecules, and the influence of fundamental chiral physical forces such as parity violation on the electroweak force.

4. Study of the origin and evolution of life from the complexity and network theory perspective (Complexity and Astrobiology Group, coordinator: Jacobo Aguirre)

Interaction, collaboration and competition between different actors represent the main driving forces behind the evolution of the biological, sociological and technological systems around us. Similarly, many astrobiological systems are so complex that to represent them we must use complex networks formed by a multitude of nodes and their interactions. From this perspective, the aim of the CAB Complexity and Astrobiology Group is to create a bridge between complexity theory and astrobiology to shed light on one of the most challenging scientific contexts of our century: the origin of life and its evolution towards the current complexity of the biosphere.

For this purpose, we focus our work on three objectives:

  • The emergence of molecular complexity in the interstellar medium during the creation of organic compounds relevant to prebiotic chemistry.

  • The first prebiotic chemical processes that took place on Earth from such compounds (brought to its surface by meteorite and comet impacts) and led to the origin of life, in order to discern whether the basic properties of life – such as the creation of diversity, inheritance and replication – can emerge naturally in a sufficiently simple model.

  • The study of the evolution of heterogeneous populations (RNA sequences, viruses and bacteria) within the framework of the RNA world and current biochemistry, as paradigms of the simplest autonomous biological entities.

Our research is carried out in close coordination with experimental studies, with an emphasis on practical and biomedical applications of theoretical predictions.

Figure. Comparison between the predictions of our NetWorld digital environment and the evolution of chemical complexity in 4 real interstellar clouds, the astrochemical environments where the most basic building blocks of life originated.

Members | Researchers