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Mutualisms are interactions that benefit all species involved. It has been widely investigated in neighbouring subjects, such as biology, ecology, sociology, and economics. However, such a reciprocal relationship in synthetic chemical systems has rarely been studied. Here, we demonstrate a mutualistic synthesis where byproducts from two orthogonal chemical reactions aid each other′s production. Disulfide exchange and hydrazone exchange were chosen to generate two dynamic combinatorial libraries. A minor tetrameric macrocycle from the active disulfide library was quantitatively amplified in the presence of the hydrazone library. This incorporation also turned on the previously inert hydrazone reaction, producing a linear species that formed a "handcuffs" catenane with the disulfide tetramer. These findings not only lend robust support to the hypothesis of "RNA‐peptide coevolution" for the origin of life but also broaden the scope of synthetic chemistry, highlighting the untapped potential of minor products from different reactions. Additionally, the co‐self‐assembly of these mutualistic entities to form supramolecular structures opens new avenues for future development of composite nanosystems with synergistic properties. [ABSTRACT FROM AUTHOR]

The origin of life (OoL) has always been a mysterious and challenging topic that puzzles human beings. Clay minerals have unique properties and wide distribution in early Earth environments. They can not only adsorb biological small molecules to catalyze their polymerization, but play an active role in the formation and evolution of protocells. In this review, the research progress on the interactions of clay minerals with biomolecules and protocells complex structures in the field of the OoL based on chemical evolution theory is summarized. The types, structures and properties of clay minerals, biological molecules and protocell models related to the OoL are introduced in detail. The mechanism of interaction between clay minerals and biological molecules, the construction of protocells and the role of clay minerals in the formation, structure and stability of protocells are systematically described. Finally, the future research priorities and challenges in the field of OoL based on clay minerals, biomolecules and protocells are discussed. It is aspired that this review can further advance the exploration of the OoL from a new perspective, and can also bring some interesting findings and ideas to the interdisciplinary research of materials, biology, chemistry and other related disciplines.Clay minerals have a variety of interactions with small biomolecules, which can be used as structural and functional templates to promote the organic synthesis of biomolecules and the formation and evolution of protocells, playing a non‐negligible role in the field of the OoL. [ABSTRACT FROM AUTHOR]

Development of chiral aggregation‐induced emission (AIE) materials toward hierarchical self‐assembly is crucial to reveal the origin and evolution of life. In this work, a pair of chiral AIE enantiomers is fabricated by attaching the typical AIE units to the chiral binaphthyl core via a single bond linkage. The AIE behavior is inherited from the introduced AIE unit while the binaphthyl unit can not only improve the photo‐physical properties but also provide the whole molecules with chirality. Moreover, as driven by the dipolar structure and chirality of the AIEgens, the hierarchical self‐assembly with different morphologies such as spheres, ribbons or fibers, flowers, and even bigger structures with various sizes can be dynamically monitored with the assembled time, which provided a favorable evidence to study the structural evolution from molecular level to a higher‐level structure. On the other hand, these AIEgens can act strong electronic acceptors due to the introduced AIE unit. By complexing them with strong electronic donors, the resulting intermolecular charge transfer can induce remarkable red emissions with the tunable properties which is much different from their individuals. This enabled it as a facile, economic, and flexible approach to develop organic photoelectric materials. [ABSTRACT FROM AUTHOR]

Astronomical impacts by small solar system bodies (meteoroids, asteroids, comets, and transitional objects) are considered a mechanism for delivering amino acids and their polymerization to proteins in early Earth conditions. High‐pressure torsion (HPT) is a new methodology to simulate such impacts and clarify the behavior of biomolecules. Herein, two amino acids, crystalline L‐serine and L‐glutamic acid that are detected in meteorites, are processed by HPT and examined by ex situ X‐ray diffraction, Raman spectroscopy, nuclear magnetic resonance, Fourier‐transform infrared spectroscopy, and in situ mechanical shear testing. No polymerization, chemical reactions, or phase transformations are detected after HPT, indicating that the stability and presence of these two amino acids in meteorites are quite reasonable. However, some microstructural and mechanical changes like crystal size reduction to the nanometer level, crystal defect formation, lattice expansion by vacancy formation, and shear strength enhancement to the steady state are found which are similar to the behaviors reported in metals and ceramics after HPT processing. [ABSTRACT FROM AUTHOR]

The ability of living organisms to persist, grow, evolve and invade environments seemingly challenges physical laws. Emerging Autonomous Systems representing autocatalytic cycles constituted of energized components in a state of Dynamic Kinetic Stability feature some of these properties. These simple theoretical models can grow, can be transferred but need an initiation to emerge and can collapse. Moreover, they can undergo kinetic selection in a way consistent with Darwinian behaviour, though they lack the ability to undergo change. The mere existence of these systems and their open‐ended growth potential are proposed to constitute a transmissible factor of a non‐coded kind. The onset and selection of epigenetic factors may therefore have preceded that of genetic polymers. Here is addressed the question of how these systems may arise from the diversity exhibited by abiotic organic matter, sometimes associated with intractable mixtures, which may actually be useful in providing initiators. The Darwinian description of evolution may therefore be merged without critical discontinuity within an origin scenario. Accordingly, such a theory would rests solely on physicochemical laws beginning with the potential of emerging autonomous systems to compete and invade the space dimension, and to further develop along other available dimensions including variability and, possibly, cognition. [ABSTRACT FROM AUTHOR]

Detecting biosignatures of life in extraterrestrial environments remains one of the primary objectives of scientific inquiry. Currently, both remote and direct detection methods are primarily aimed at identifying key molecular classes fundamental to terrestrial biology. However, a more universally applicable spectroscopic approach could involve searching for homochiral molecules. Thus, this perspective delves into the significance of homochirality as a critical factor in the origin of life. Without homochirality, the formation of self‐recognizing and self‐replicating complex molecules would be hindered. The various hypotheses concerning the origin of homochiral molecules have been explored and analyzed within this context. This perspective emphasizes the potential for discovering extraterrestrial microscopic life through the detection of homochiral molecules using chirodetecting methods such as chromatography and chiroptical spectroscopy or circular polarimetry as a promising remote technique. This discussion highlights the importance of homochirality in the broader search for life beyond Earth and underscores the need for innovative methodologies and instrumentation in astrobiological research. These techniques can be an effective method for detecting homochirality on future planetary missions. [ABSTRACT FROM AUTHOR]

Urea is believed to have been essential to the synthesis of prebiotic nucleotides and thereby the RNA or DNA of the first lifeforms. Models suggesting that life began in wet‐dry cycles around shallow aquatic ponds imply that reactants such as urea were exposed to deep ultraviolet irradiation from the young sun. Detrimental photodissociation of urea induced by deep UV excitation potentially challenges these models. We here follow the primary deep ultraviolet photochemistry of aqueous urea. The data show that urea is barely excited at 200 nm due to weak ultraviolet absorption. The likelihood of photodissociation is further reduced by strong intra‐molecular coupling of the CN and CO stretch vibrations accompanied by an efficient dissipation of the excitation energy to the surrounding water molecules mitigated by urea‐water hydrogen bonds. We find that 54±5 % of the excited urea molecules dissociate. Reactions between the photoproducts and surrounding solvent molecules form carbamic acid or the carbamate anions within 0.6 ps. The molecules that do not dissociate return to the electronic ground state in 2 ps. Interestingly, the photodissociation processes of urea in the aqueous phase is different from earlier reported reactions observed following the VUV photolysis of urea in noble gas matrices and highlight the potential influence of water on the prebiotic photochemistry. [ABSTRACT FROM AUTHOR]

Resolving a robust phylogeny of an organismal group is often hindered by the limited availability of samples suitable for genomic or transcriptomic sequencing. Even for lineages of notable importance in evolutionary ecology, our phylogenetic comprehension remains largely unsatisfactory due to the challenges of acquiring samples across the clade. The long‐horned beetle genus Anoplophora Hope exemplifies such a group, globally renowned for two invasive pests—the Asian long‐horned beetle and citrus long‐horned beetle—which have inflicted significant damage to deciduous hardwood forest in North America and Europe. In contrast to the two temperate pests, the remaining 50 species in the genus inhabit subtropical forests of Southeast Asia, where most species are only infrequently encountered. Here, we present the first comprehensive phylogeny of Anoplophora using a PCR‐based target enrichment museomics approach. As a case study of employing PCR‐generated custom probes, we demonstrate the robustness and cost‐effectiveness of this in‐house method in successfully acquiring sequence data from historical specimens. Through extensive sampling of Anoplophora using museum specimens, we reveal a non‐sister relationship between the two temperate species and provide evidence for addressing taxonomic conundrums. Our biogeographical analyses indicate that the adaptation of the two temperate species occurred independently during the late Pliocene and Pleistocene after the establishment of temperate forests in East Asia in the late Miocene. Our findings highlight the importance of comprehensive phylogenetic inference in understanding the patterns and processes of these beetles' adaptation to temperate forests and lay the groundwork for investigating the genetic mechanism underlying life in the cold. [ABSTRACT FROM AUTHOR]

At the origin, the emergence of proteins was based on crucial prebiotic stages in which simple amino acids‐based building blocks spontaneously evolved from the prebiotic soup into random proto‐polymers called protoproteins. Despite advances in modern peptide synthesis, these prebiotic chemical routes to protoproteins remain puzzling. We discuss in this perspective how polymer science and systems chemistry are reaching a point of convergence in which simple monomers called N‐carboxyanhydrides would be able to form such protoproteins via the emergence of a protometabolic cycle involving aqueous polymerization and featuring macromolecular Darwinism behavior. [ABSTRACT FROM AUTHOR]

The osmotic rupture of a cell, its osmotic lysis or cytolysis, is a phenomenon that active biological cell volume regulation mechanisms have evolved in the cell membrane to avoid. How then, at the origin of life, did the first protocells survive prior to such active processes? The pores of alkaline hydrothermal vents in the oceans form natural nanoreactors in which osmosis across a mineral membrane plays a fundamental role. Here, we discuss the dynamics of lysis and its avoidance in an abiotic system without any active mechanisms, reliant upon self‐organized behaviour, similar to the first self‐organized mineral membranes within which complex chemistry may have begun to evolve into metabolism. We show that such mineral nanoreactors could function as protocells without exploding because their self‐organized dynamics have a large regime in parameter space where osmotic lysis does not occur and homeostasis is possible. The beginnings of Darwinian evolution in proto‐biochemistry must have involved the survival of protocells that remained within such a safe regime. [ABSTRACT FROM AUTHOR]

Hypervelocity impacts can generate hydrothermal systems, which have been suggested as candidate environments for prebiotic chemistry on the early Earth. The Haughton impact structure (a 23 km diameter crater located on Devon Island, Nunavut, Arctic Canada) displays evidence of water‐rock alteration indicative of a hydrothermal system generated from a cosmic impact. To model the formation of this crater and subsequent hydrothermal alteration, we have successfully developed a new two‐code methodology that utilizes a shock physics code and a hydrothermal code (HYDROTHERM). We can best reproduce the Haughton crater with a ∼700 m diameter projectile with an impact velocity of 14 km/s. With our approach, we were able to match all the major geological constraints observed at the Haughton impact structure. Our models show that the Haughton crater interior could have sustained temperatures ideal for thermophilic and hyperthermophilic life (50–120°C) for more than 50,000 years, indicating that these systems can sustain prebiotic chemistry and life for longer than previously estimated. Plain Language Summary: Impacts of cosmic objects moving at hypervelocity can create high‐temperature hydrothermal systems. These environments have been suggested as possible sites for the formation of prebiotic chemistry on early Earth. The Haughton impact structure on Devon Island, Nunavut, Arctic Canada, has a well‐studied impact‐generated hydrothermal system and offers a unique analog to similar systems on early Earth or Mars. Here, we present a two‐code modeling technique to model the full evolution of the impact‐generated hydrothermal system at Haughton. We were able to match the major geological constraints observed at the Haughton structure. Our models suggest that the Haughton crater interior should have sustained temperatures ideal for early life (50–120°C) for >50,000 years, indicating that these systems can sustain life for longer than previously estimated. Key Points: The Haughton impact structure can be better modeled utilizing a smaller impactor (∼700 m in diameter) than previously estimatedWe successfully match a multitude of observed fluid alterations observed at Haughton with our novel two‐code methodologyOur models show that the Haughton crater interior sustained temperatures ideal for thermophilic and hyperthermophilic life for >50,000 years [ABSTRACT FROM AUTHOR]

Ice has been suggested to have played a significant role in the origin of life partly owing to its ability to concentrate organic molecules and promote reaction efficiency. However, the techniques for studying organic molecules in ice are absorption‐based, which limits the sensitivity of measurements. Here we introduce an emission‐based method to study organic molecules in water ice: the phosphorescence displays high sensitivity depending on the hydration state of an organic salt probe, acridinium iodide (ADI). The designed ADI aqueous system exhibits phosphorescence that can be severely perturbed when the temperature is higher than 110 K at a concentration of the order of 10−5 M, indicating changes in hydration for ADI. Using the ADI phosphorescent probe, it is found that the microstructures of water ice, i.e., crystalline vs. glassy, can be strongly dictated by a trace amount (as low as 10−5 M) of water‐soluble organic molecules. Consistent with cryoSEM images and temperature‐dependent Raman spectral data, the ADI is dehydrated in more crystalline ice and hydrated in more glassy ice. The current investigation serves as a starting point for using more sensitive spectroscopic techniques for studying water‐organics interactions at a much lower concentration and wider temperature range. [ABSTRACT FROM AUTHOR]

Having evolved from a prokaryotic origin, mitochondria retain pathways required for the catabolism of energy‐rich molecules and for the biosynthesis of molecules that aid catabolism and/or participate in other cellular processes essential for life of the cell. Reviewed here are details of the mitochondrial fatty acid biosynthetic pathway (FAS II) and its role in building both the octanoic acid precursor for lipoic acid biosynthesis (LAS) and longer‐chain fatty acids functioning in chaperoning the assembly of mitochondrial multisubunit complexes. Also covered are the details of mitochondrial lipoic acid biosynthesis, which is distinct from that of prokaryotes, and the attachment of lipoic acid to subunits of pyruvate dehydrogenase, α‐ketoglutarate dehydrogenase, and glycine cleavage system complexes. Special emphasis has been placed on presenting what is currently known about the interconnected paths and loops linking the FAS II–LAS pathway and two other mitochondrial realms, the organellar translation machinery and Fe‐S cluster biosynthesis and function. [ABSTRACT FROM AUTHOR]

The development of self‐replicating systems is of great importance in research on the origin of life. As the most iconic molecules, nucleic acids have provided prominent examples of the fabrication of self‐replicating artificial nanostructures. However, it is still challenging to construct sophisticated synthetic systems that can create large‐scale or three‐dimensionally ordered nanomaterials using self‐replicating nanostructures. By integrating a template system containing DNA‐functionalized colloidal seeds with a simplified DNA strand‐displacement circuit programmed subsystem to produce DNA‐functionalized colloidal copies, we developed a facile enthalpy‐mediated strategy to control the replication and catalytic assembly of DNA‐functionalized colloids in a time‐dependent manner. The replication efficiency and crystal quality of the resulting superlattice structures can be effectively increased by regulating the molar ratio of the template to the copy colloids. By constructing binary systems from two types of gold nanoparticles (or proteins), superlattice structures with different crystal symmetries can be obtained through the replication and catalytic assembly processes. This programmable enthalpy‐mediated approach was easily leveraged to achieve the phase transformation and catalytic amplification of colloidal crystals starting from different initial template crystals. This work offers a potential way to construct self‐replicating artificial systems that exhibit complicated phase behaviors and can produce large‐scale superlattice nanomaterials. [ABSTRACT FROM AUTHOR]

The world in which we live is homochiral. The ribose units that form the backbone of DNA and RNA are all D‐configured and the encoded amino acids that comprise the proteins of all living species feature an all‐L‐configuration at the α‐carbon atoms. The homochirality of α‐amino acids is essential for folding of the peptides into well‐defined and functional 3D structures and the homochirality of D‐ribose is crucial for helix formation and base‐pairing. The question of why nature uses only encoded L‐α‐amino acids is not understood. Herein, we show that an RNA‐peptide world, in which peptides grow on RNAs constructed from D‐ribose, leads to the self‐selection of homo‐L‐peptides, which provides a possible explanation for the homo‐D‐ribose and homo‐L‐amino acid combination seen in nature. [ABSTRACT FROM AUTHOR]

Die Welt, in der wir leben, ist homochiral. Die Riboseeinheiten, die das Rückgrat von DNA und RNA bilden, sind alle D‐konfiguriert, und die kodierten Aminosäuren, aus denen die Proteine aller lebenden Arten bestehen, weisen an den α‐Kohlenstoffatomen eine L‐Konfiguration auf. Die Homochiralität der α‐Aminosäuren ist unerlässlich für die Faltung der Peptide in wohldefinierte und funktionelle 3D‐Strukturen und die Homochiralität der D‐Ribose ist entscheidend für die Ausbildung einer Helix und die Basenpaarung. Die Frage, warum die Natur nur kodierte L‐α‐Aminosäuren verwendet, ist nicht geklärt. Wir zeigen hier, dass eine RNA‐Peptid‐Welt, in der Peptide an aus D‐Ribose aufgebauten RNAs wachsen, zur Selbstselektion von homo‐L‐Peptiden führt, was eine mögliche Erklärung für die in der Natur beobachtete Kombination von homo‐D‐Ribose und homo‐L‐Aminosäuren liefert. [ABSTRACT FROM AUTHOR]

It has long been thought that abiogenesis requires a process of selection and evolution at the molecular level, but this process is hard to explore experimentally. One solution could be the use of automation in experiments which could allow for traceability and the ability to explore a larger reaction space. We report a fully programmable and automated platform to explore the reactions of amino acids in the presence of mineral environments. The robotic system is based upon the Chemputer system which has well defined modules, software, and a chemical programming language to orchestrate the chemical processes, including analysis. The reaction mixtures were analysed with tandem mass spectrometry and a peptide sequencing algorithm. Each experiment was screened for 1,398,100 possible unique sequences, and more than 550 specifically defined sequences were confirmed experimentally. This work aimed to develop a new understanding of selection in repeated cycles of polymerisation reactions to explore the emergence of well‐defined amino acid sequences. We found that the outcome of oligomerisation was significantly influenced by the presence of different minerals, and that a serpentine environment selects glycine and phenylalanine rich fragments that enable the formation of longer oligomers with well‐defined sequences as a function of cycle number. [ABSTRACT FROM AUTHOR]

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time‐consuming nature of studies to find new anticancer agents makes it necessary to have well‐designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi‐synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal‐oriented studies for drug development against CNS malignancies. [ABSTRACT FROM AUTHOR]

Astrobiology research seeks to understand how life begins and evolves, and to determine whether life exist elsewhere in the universe. The discovery of diverse ocean worlds has significantly expanded the number of planetary bodies in the Solar System that could potentially contain life. Of the recognized ocean worlds, Saturn's moon Enceladus stands out because it appears to meet all requirements to sustain life. For that reason, robotic mission concepts are being developed to determine whether Enceladus' ocean is inhabited. The theory of organic chemical evolution (OCE) represents an ideal framework to guide this exploration strategy, articulating investigations and associated measurements of organic matter in the subsurface ocean. Within this reference frame, the immediate priority with the lowest science risk would be to understand molecular and structural properties of bulk organic matter in the ocean, and search for metabolic precursors and biochemical building blocks, both free and bound. This could be supplemented with "high‐risk, high‐reward" searches for functional polymers, catalytic activity, and cell‐like objects with traits indicative of evolutionary adaptations. The theory of OCE provides a robust scientific foundation for the astrobiological exploration of ocean worlds, fostering a productive path to discovery with lower mission risk that could be implemented with existing technology. Strong synergies between astrobiology and Earth‐bound research could ensue from this exploration strategy particularly in the context of terrestrial analog studies and laboratory simulations. Plain Language Summary: There is a diversity of "ocean worlds" in our Solar System, which are of great scientific interest. Enceladus, a small moon of Saturn, has a global subsurface ocean that could sustain life and contains complex organic matter. To further understand the biological potential of Enceladus, and other ocean worlds, we need to consider how abiotic and prebiotic chemistry in Enceladus's ocean might play a role in the origin of life. The theory of organic chemical evolution provides the ideal framework to address this question. The top priority would be to study the organic inventory in the ocean, and to search for the basic building blocks of life, as well as simple compounds involved in metabolic processes. Next, we should search for complex polymers and cell‐like structures with traits suggesting Darwinian evolution. This exploration strategy is a solid foundation for discovery and can be done with current technology, which lowers the risk and complexity of spaceflight missions. Key Points: Enceladus is one of the most compelling destinations in the solar system for exobiology explorationThe theory of organic chemical evolution provides a framework for the continued and systematic exploration of Enceladus and other ocean worldsWith this exploration framework biotic, abiotic, and prebiotic scenarios are all possible outcomes with profound implications [ABSTRACT FROM AUTHOR]

Exploration of the unique chemical properties of interfaces can unlock new understanding. A striking example is the finding of accelerated reactions, particularly spontaneous oxidation reactions, that occur without assistance of catalysts or external oxidants at the air interface of both aqueous and organic solutions (provided they contain some water). This finding opened a new area of interfacial chemistry but also caused heated debate regarding the primary chemical species responsible for the observed oxidation. An overview of the literature covering oxidation in microdroplets with air interfaces is provided, together with a critical examination of previous findings and hypotheses. The water radical cation/radical anion pair, formed spontaneously and responsible for the electric field at or near the droplet/air interface, is suggested to constitute the primary redox species. Mechanisms of accelerated microdroplet reactions are critically discussed and it is shown that hydroxyl radical/hydrogen peroxide formation in microdroplets does not require that these species be the primary oxidant. Instead, we suggest that hydroxyl radical and hydrogen peroxide are the products of water radical cation decay in water. The importance of microdroplet chemistry in the prebiotic environment is sketched briefly and the role of partial solvation in reaction acceleration is noted. [ABSTRACT FROM AUTHOR]

Aqueous chemistry within carbonaceous planetesimals is promising for synthesizing prebiotic organic matter essential to all life. Meteorites derived from these planetesimals delivered these life building blocks to the early Earth, potentially facilitating the origins of life. Here, we studied the formation of vitamin B3 as it is an important precursor of the coenzyme NAD(P)(H), which is essential for the metabolism of all life as we know it. We propose a new reaction mechanism based on known experiments in the literature that explains the synthesis of vitamin B3. It combines the sugar precursors glyceraldehyde or dihydroxyacetone with the amino acids aspartic acid or asparagine in aqueous solution without oxygen or other oxidizing agents. We performed thermochemical equilibrium calculations to test the thermodynamic favorability. The predicted vitamin B3 abundances resulting from this new pathway were compared with measured values in asteroids and meteorites. We conclude that competition for reactants and decomposition by hydrolysis are necessary to explain the prebiotic content of meteorites. In sum, our model fits well into the complex network of chemical pathways active in this environment. [ABSTRACT FROM AUTHOR]

Compartmentalization protected biomolecules from the fluctuating environments of early Earth. Although contemporary cells mostly use phospholipid‐based bilayer membranes, the utility of non‐bilayer compartments was not ruled out during the prebiotic and modern eras. In the present study, we demonstrated the prebiotic synthesis of lipidated cationic amino acid‐based amphiphiles [lauryl ester of lysine (LysL); ornithine (OrnL); and 2,4‐diamino butyric acid (DabL)] using model dry‐down reaction. These amphiphiles self‐assemble into micellar membranes. However, the OrnL and DabL‐based micelles undergo pH‐responsive transformation to lipid droplet‐like morphologies, a modelcompartment in the prebiotic Earth. These cationic droplets encapsulated prebiotic molecules (isoprene) and assisted electron transfer reaction to synthesize isoprenoid derivatives at primitive Earth conditions. The self‐assembly of prebiotic amphiphiles, their transformation to droplet compartments, and droplet‐assisted C−C bond formation reaction might have helped the evolution to synthesize various biomolecules required for the origin of life. [ABSTRACT FROM AUTHOR]

Glycerophospholipid membranes are one of the key cellular components. Still, their species‐dependent composition and homochirality remain an elusive subject. In the context of the astrophysical circularly polarized light scenario likely involved in the generation of a chiral bias in meteoritic amino and sugar acids in space, and consequently in the origin of life's homochirality on Earth, this study reports the first measurements of circular dichroism and anisotropy spectra of a selection of glycerophospholipids, their chiral backbones and their analogs. The rather low asymmetry in the interaction of UV/VUV circularly polarized light with sn‐glycerol‐1/3‐phosphate indicates that chiral photons would have been unlikely to directly induce symmetry breaking to membrane lipids. In contrast, the anisotropy spectra of d‐3‐phosphoglyceric acid and d‐glyceraldehyde‐3‐phosphate unveil up to 20 and 100 times higher maximum anisotropy factor values, respectively. This first experimental report, targeted on investigating the origins of phospholipid symmetry breaking, opens up new avenues of research to explore alternative mechanisms leading to membrane lipid homochirality, while providing important clues for the search for chiral biosignatures of extant and/or extinct life in space, in particular for the ExoMars 2028 mission. [ABSTRACT FROM AUTHOR]

Hydrothermal vents harbor numerous microbial communities rich in reduced carbon species such as formate, acetate, and hydrocarbons. Such essential chemicals for life are produced by H2‐dependent CO2 reduction, where serpentinization provides continuous H2 and thermal energy. Here, we show that silica‐supported bimetallic Co−Fe alloys, naturally occurring minerals around serpentinite, can convert CO2 and H2O to key metabolic intermediates of the acetyl coenzyme A pathway such as formate (up to 72 mM), acetate, and pyruvate under mild hydrothermal vent conditions. Long‐chain hydrocarbons up to C6 including propene are also detected, just as in the Lost City hydrothermal field. The effects of promoters on structural properties and catalytic functionalities of the Co−Fe alloy are systematically investigated by incorporating a series of alkali and alkaline earth metals including Na, Mg, K, and Ca. Alkali and alkaline earth metals resulted in higher formate concentrations when dissolved in water and increased reaction pH, while alkaline earth metals also favored the formation of insoluble hydroxides and carbonates similar to the constituent minerals of the chimneys at the Lost City hydrothermal fields. [ABSTRACT FROM AUTHOR]

Metabolic modelling approaches have become the powerful tools in modern biology. These mathematical models are widely used to predict metabolic phenotypes of the organisms or communities of interest, and to identify metabolic targets in metabolic engineering. Apart from a broad range of industrial applications, the possibility of using metabolic modelling in the contexts of astrobiology are poorly explored. In this mini‐review, we consolidated the concepts and related applications of applying metabolic modelling in studying organisms in space‐related environments, specifically the extremophilic microbes. We recapitulated the current state of the art in metabolic modelling approaches and their advantages in the astrobiological context. Our review encompassed the applications of metabolic modelling in the theoretical investigation of the origin of life within prebiotic environments, as well as the compilation of existing uses of genome‐scale metabolic models of extremophiles. Furthermore, we emphasize the current challenges associated with applying this technique in extreme environments, and conclude this review by discussing the potential implementation of metabolic models to explore theoretically optimal metabolic networks under various space conditions. Through this mini‐review, our aim is to highlight the potential of metabolic modelling in advancing the study of astrobiology. [ABSTRACT FROM AUTHOR]

The RNA World theory for the origin of life requires polymers to be generated initially by abiotic reactions. Experiments have studied polymerization of 5′‐monophosphates, 2′,3′‐cyclic phosphates, and 5′‐triphosphates. We consider theoretical models of polymerization in solution illustrating the differences between these cases. We consider (i) a basic model where all monomers undergo reversible joining and breaking; (ii) a model where 2′,3′‐cyclic phosphates can join, and breaking regenerates the cyclic phosphate; (iii) a model where 5′‐triphosphates can join irreversibly, in addition to the joining and breaking of 2′,3′‐cyclic phosphates. In cases (i) and (ii) there is an equilibrium steady state with balance between making and breaking bonds. In case (iii) there is a circular reaction flux in which monomers are activated by an external phosphate source, activated monomers form polymers, and polymers break to release non‐activated monomers. The mean length can be calculated as a function of concentration. In case (iii), the mean length switches from a low‐concentration regime controlled by the 5′‐triphosphates to a high‐concentration regime controlled by the 2′,3′‐cyclic phosphates. The circular reaction flux is reminiscent of a metabolism. If formation of 5'‐triphosphates was already in place for RNA synthesis, ATP could subsequently been coopted for metabolism. [ABSTRACT FROM AUTHOR]

The origins of biopolymers pose fascinating questions in prebiotic chemistry. The marvelous assembly proficiencies of biopolymers suggest they are winners of a competitive evolutionary process. Sophisticated molecular assembly is ubiquitous in life where it is often emergent upon polymerization. We focus on the influence of molecular assembly on hydrolysis rates in aqueous media and suggest that assembly was crucial for biopolymer selection. In this model, incremental enrichment of some molecular species during chemical evolution was partially driven by the interplay of kinetics of synthesis and hydrolysis. We document a general attenuation of hydrolysis by assembly (i.e., recalcitrance) for all universal biopolymers and highlight the likely role of assembly in the survival of the 'fittest' molecules during chemical evolution. [ABSTRACT FROM AUTHOR]

Artificial cells are synthetic constructs that emulate natural cells, with potential applications in areas of energy science, environmental treatment, and the study of life's origins. Nevertheless, the construction of artificial cells is a formidable undertaking, given the intricate nature of natural cells in structures, functions, and working mechanisms. With precise control, high automation, and excellent uniformity, microfluidics has emerged as a promising approach for the construction of artificial cells. This review summarizes the latest microfluidic techniques utilized to construct artificial cells, ranging from simple droplets to sophisticated cell‐inspired systems. These include the generation of droplets, the production of vesicles (lipid‐based and polymer‐based vesicles), the fabrication of polymeric microparticles with various compartments, shapes, and microstructures, as well as the manufacture of sophisticated cell‐inspired systems. The characteristics of different methods for the construction of artificial cells are discussed in detail. Furthermore, the wide‐ranging applications of artificial cells are also showcased. Finally, contemporary obstacles and forthcoming advancements are discussed in the field of microfluidic‐based artificial cells. This review is supposed to stimulate research in the construction of more functional and natural‐like artificial cells, as well as works in the fields of material, biology, environment, medicine, and energy. [ABSTRACT FROM AUTHOR]

Anangu, Pitjantjatjara and Yankunytjatjara people living in the north‐western areas of South Australia, conceptualize changes in the surface of land as evincing the presence of Ancestral power. Rain is one such catalyst of change, though it is by no means a certainty on the Pitjantjatjara Yankunytjatjara Lands. When it does appear, water does not stay long on the surface: it is shimmering and unstable. This chapter examines the nature of various water sources in contemporary indigenous life, the spatial relationships between earth and sky and the dialectic between life and death that they mediate. [ABSTRACT FROM AUTHOR]

The Moon‐forming impact vaporized part of Earth's mantle, and turned the rest into a magma ocean, from which carbon dioxide degassed into the atmosphere, where it stayed until water rained out to form the oceans. The rain dissolved CO2 and made it available to react with transition metal catalysts in the Earth's crust so as to ultimately generate the organic compounds that form the backbone of microbial metabolism. The Moon‐forming impact was key in building a planet with the capacity to generate life in that it converted carbon on Earth into a homogeneous and accessible substrate for organic synthesis. Today all ecosystems, without exception, depend upon primary producers, organisms that fix CO2. According to theories of autotrophic origin, it has always been that way, because autotrophic theories posit that the first forms of life generated all the molecules needed to build a cell from CO2, forging a direct line of continuity between Earth's initial CO2‐rich atmosphere and the first microorganisms. By modern accounts these were chemolithoautotrophic archaea and bacteria that initially colonized the crust and still inhabit that environment today. [ABSTRACT FROM AUTHOR]

Liquid–liquid phase separation (LLPS) is a process that often occurs due to binding between oppositely charged biopolymers, and has gained increasing attention recently due to their ubiquity in biological systems and ability to direct essential cellular processes. However, while these discoveries in biology are recent, the field of origins of life has been investigating LLPS for nearly 100 years, ever since the first suggestions by Oparin and Haldane that primitive LLPS could have been precursors to the first cells on Earth. Since then, a significant amount of work has been done to elucidate different primitive LLPS systems that could have been relevant as protocellular models. Given the structural similarities between primitive LLPS and modern membraneless organelles, there may even be an evolutionary link between the two, although this remains a question to be answered. Nevertheless, in order to answer this, a source that compares compositional aspects of modern biological condensates and primitive LLPS is necessary. Here, we first focus on membraneless organelles composed of intrinsically disordered proteins (IDPs) and nucleic acids. Then, as a parallel, we explore primitive membraneless compartments composed of simple biopolymers such as short peptides and nucleic acids. This is followed by a discussion of how the first biomolecules on Earth may have originated, analyzing the environmental and chemical conditions that could have favored primitive LLPS processes. Finally, we directly compare composition of modern biological condensates and primitive phase‐separated compartments, further discussing the potential of primitive IDPs on early Earth, but also the evolution from membraneless to membrane‐bound cells. This review aims to provide a compositional comparison of modern and primitive phase‐separated structures in order to help researchers in both fields understand the current state of knowledge, how this knowledge evolved, and the current gaps that need to be further addressed. [ABSTRACT FROM AUTHOR]

The construction of hypothetical environments to produce organic molecules such as metabolic intermediates or amino acids is the subject of ongoing research into the emergence of life. Experiments specifically focused on an anabolic approach typically rely on a mineral catalyst to facilitate the supply of organics that may have produced prebiotic building blocks for life. Alternatively to a true catalytic system, a mineral could be sacrificially oxidized in the production of organics, necessitating the emergent 'life' to turn to virgin materials for each iteration of metabolic processes. The aim of this perspective is to view the current 'metabolism‐first' literature through the lens of materials chemistry to evaluate the need for higher catalytic activity and materials analyses. While many elegant studies have detailed the production of chemical building blocks under geologically plausible and biologically relevant conditions, few appear to do so with sub‐stoichiometric amounts of metals or minerals. Moving toward sub‐stoichiometric metals with rigorous materials analyses is necessary to demonstrate the viability of an elusive cornerstone of the 'metabolism‐first' hypotheses: catalysis. We emphasize that future work should aim to demonstrate decreased catalyst loading, increased productivity, and/or rigorous materials analyses for evidence of true catalysis. [ABSTRACT FROM AUTHOR]

The spontaneous emergence of function from diverse RNA sequence pools is widely considered an important transition in the origin of life. Here we show that diverse sequence pools are not a prerequisite for the emergence of function. Starting five independent selection experiments each from a single RNA seed sequence - comprising a central homopolymeric poly-A (or poly-U) segment flanked by different conserved primer binding sites - we observe transformation (continuous drift) of the seeds into low diversity sequence pools by mutation, truncation and recombination without ever reaching that of a random pool even after 24 rounds. Upon continuous error prone replication and selection for ATP binding we isolate specific ATP- or GTPbinding aptamers with low micromolar affinities. Our results have implications for early RNA evolution in the light of the high mutation rates associated with both non-enzymatic and enzymatic prebiotic RNA replication. [ABSTRACT FROM AUTHOR]

Demonstrating RNA catalysis within prebiotically relevant models of primordial cells (protocells) remains a challenge in origins of life research. Fatty acid vesicles encapsulating genomic and catalytic RNAs (ribozymes) are attractive models for protocells; however, RNA catalysis has largely been incompatible with fatty acid vesicles due to their instability in the presence of Mg2+ at the concentrations required for ribozyme function. Here, we report a ribozyme that catalyzes template‐directed RNA ligation at low Mg2+ concentrations and thus remains active within stable vesicles. Ribose and adenine, both prebiotically relevant molecules, were found to greatly reduce Mg2+‐induced RNA leakage from vesicles. When we co‐encapsulated the ribozyme, substrate, and template within fatty acid vesicles, we observed efficient RNA‐catalyzed RNA ligation upon subsequent addition of Mg2+. Our work shows that RNA‐catalyzed RNA assembly can occur efficiently within prebiotically plausible fatty acid vesicles and represents a step toward the replication of primordial genomes within self‐replicating protocells. [ABSTRACT FROM AUTHOR]

The cellular environment offers some unique features to carry out polymerizations under controlled conditions. Polymerization of monomers in cellular compartments and on the surface of living organisms holds much promise in the engineering of biofunctional synthetic polymers for sensing and probing cell behavior and of late has received significant interest. This effort lies at the interface of synthetic biology and polymer chemistry and can pave the way for innovative solutions to many existing challenges in healthcare, environment, energy, and the study of the "origin of life". Herein, recent advances in controlled polymerization strategies for intracellular and surface of living cells are presented with a particular emphasis on nanobiomedicines. Furthermore, polymerization strategies, cytocompatible monomer structures, compatible cell lines and microorganisms, nature of stimulus, catalysts, along with specific polymerization conditions to produce non-natural biofunctional polymers that can undergo polymerization-induced self-assembly within and onto the living cells are presented in detail. Furthermore, the review offers a window into the future of such novel emerging synthetic bionano systems in biomedical sciences. [ABSTRACT FROM AUTHOR]

Mountains are renowned for their bountiful biodiversity. Explanations on the origin of such abundant life are usually regarded to their orogenic history. However, ancient mountain systems with geological stability also exhibit astounding levels of number of species and endemism, as illustrated by the Brazilian Quartzitic Mountains (BQM) in Eastern South America. Thus, cycles of climatic changes over the last couple million years are usually assumed to play an important role in the origin of mountainous biota. These climatic oscillations potentially isolated and reconnected adjacent populations, a phenomenon known as flickering connectivity, accelerating speciation events due to range fragmentation, dispersion, secondary contact, and hybridization. To evaluate the role of the climatic fluctuations on the diversification of the BQM biota, we estimated the ancient demography of distinct endemic species of animals and plants using hierarchical approximate Bayesian computation analysis and Ecological Niche Modelling. Additionally, we evaluated if climatic oscillations have driven a genetic spatial congruence in the genetic structure of codistributed species from the Espinhaço Range, one of the main BQM areas. Our results show that the majority of plant lineages underwent a synchronous expansion over the Last Glacial Maximum (LGM, c. 21 thousand years ago), although we could not obtain a clear demographic pattern for the animal lineages. We also obtained a signal of a congruent phylogeographic break between lineages endemic to the Espinhaço Range, suggesting how ancient climatic oscillations might have driven the evolutionary history of the Espinhaço's biota. [ABSTRACT FROM AUTHOR]

Self‐replication of nucleic acids in the absence of enzymes represents an important and poorly understood step in the origin of life as such reported systems are strongly hindered by product inhibition. Studying one of the few successful examples of enzymatic DNA self‐replication based on a simple ligation chain reaction, lesion‐induced DNA amplification (LIDA), can shed light on how this fundamental process may have originally evolved. To identify the unknown factors that lead LIDA to overcome product inhibition we have employed isothermal titration calorimetry and global fitting of time‐dependent ligation data to characterize the individual steps of the amplification process. We find that incorporating the abasic lesion into one of the four primers substantially decreases the stability difference between the product and intermediate complexes compared with complexes without the abasic group. In the presence of T4 DNA ligase this stability gap is further reduced by two orders of magnitude revealing that the ligase also helps overcome product inhibition. Kinetic simulations reveal that the intermediate complex stability and the magnitude of the ligation rate constant significantly impact the rate of self‐replication, suggesting that catalysts that both facilitate ligation and stabilize the intermediate complex might be a route to efficient nonenzymatic replication. [ABSTRACT FROM AUTHOR]

Viruses are ubiquitous in every habitat and are the most abundant species on our planet. Most ancient are RNA‐containing viruses. They may have contributed to the origin of life, since naked RNA‐only viruses, the viroids, lack genetic information. They fulfil several criteria of life. Could such structures have contributed to life on exoplanets somewhere in the Universe? Viruses are innovative, can integrate into genomes thereby supplying novel information and immunity to the host, protecting against superinfection by exogenous viruses. They are the drivers of evolution. As such they contributed e. g. to the placenta in mammals. The human chromosomes consist of about 50 % viral elements. Sub‐viral structures such as transposable elements can contribute to genetics beyond Darwinian mutations. Bacterial viruses, the phages, can help to recycle nutrients in the oceans and our intestines and can destroy multi‐drug resistant bacteria as phage‐therapy. They may be a way out, if antibiotics fail. Antibiotic resistance my soon become critical. Phage therapy is a hundred years old, but has been neglected. Novel technologies may be able to reactivate this technology. [ABSTRACT FROM AUTHOR]

RNA is a molecule that can both store genetic information and perform catalytic reactions. This observed dualism places RNA into the limelight of concepts about the origin of life. The RNA world concept argues that life started from self‐replicating RNA molecules, which evolved toward increasingly complex structures. Recently, we demonstrated that RNA, with the help of conserved non‐canonical nucleosides, which are also putative relics of an early RNA world, had the ability to grow peptides covalently connected to RNA nucleobases, creating RNA‐peptide chimeras. It is conceivable that such molecules, which combined the information‐coding properties of RNA with the catalytic potential of amino acid side chains, were once the structures from which life emerged. Herein, we report prebiotic chemistry that enabled the loading of both nucleosides and RNAs with amino acids as the first step toward RNA‐based peptide synthesis in a putative RNA‐peptide world. [ABSTRACT FROM AUTHOR]

Deep‐sea hydrothermal systems provide ideal conditions for prebiotic reactions and ancient metabolic pathways and, therefore, might have played a pivotal role in the emergence of life. To understand this role better, it is paramount to examine fundamental interactions between hydrothermal processes, non‐living matter, and microbial life in deep time. However, the distribution and diversity of microbial communities in ancient deep‐sea hydrothermal systems are still poorly constrained, so evolutionary, and ecological relationships remain unclear. One important reason is an insufficient understanding of the formation of diagnostic microbial biosignatures in such settings and their preservation through geological time. This contribution centers around microbial biosignatures in Precambrian deep‐sea hydrothermal sulfide deposits. Intending to provide a valuable resource for scientists from across the natural sciences whose research is concerned with the origins of life, we first introduce different types of biosignatures that can be preserved over geological timescales (rock fabrics and textures, microfossils, mineral precipitates, carbonaceous matter, trace metal, and isotope geochemical signatures). We then review selected reports of biosignatures from Precambrian deep‐sea hydrothermal sulfide deposits and discuss their geobiological significance. Our survey highlights that Precambrian hydrothermal sulfide deposits potentially encode valuable information on environmental conditions, the presence and nature of microbial life, and the complex interactions between fluids, micro‐organisms, and minerals. It further emphasizes that the geobiological interpretation of these records is challenging and requires the concerted application of analytical and experimental methods from various fields, including geology, mineralogy, geochemistry, and microbiology. Well‐orchestrated multidisciplinary studies allow us to understand the formation and preservation of microbial biosignatures in deep‐sea hydrothermal sulfide systems and thus help unravel the fundamental geobiology of ancient settings. This, in turn, is critical for reconstructing life's emergence and early evolution on Earth and the search for life elsewhere in the universe. [ABSTRACT FROM AUTHOR]

How life emerged from simple non‐life chemicals on the ancient Earth is one of the greatest mysteries in biology. The gene expression system of extant life is based on the interdependence between multiple molecular species (DNA, RNA, and proteins). While DNA is mainly used as genetic material and proteins as functional molecules in modern biology, RNA serves as both genetic material and enzymes (ribozymes). Thus, the evolution of life may have begun with the birth of a ribozyme that replicated itself (the RNA world hypothesis), and proteins and DNA joined later. However, the complete self‐replication of ribozymes from monomeric substrates has not yet been demonstrated experimentally, due to their limited activity and stability. In contrast, peptides are more chemically stable and are considered to have existed on the ancient Earth, leading to the hypothesis of RNA–peptide co‐evolution from the very beginning. Our group and collaborators recently demonstrated that (1) peptides with both hydrophobic and cationic moieties (e.g., KKVVVVVV) form β‐amyloid aggregates that adsorb RNA and enhance RNA synthesis by an artificial RNA polymerase ribozyme and (2) a simple peptide with only seven amino acid types (especially rich in valine and lysine) can fold into the ancient β‐barrel conserved in various enzymes, including the core of cellular RNA polymerases. These findings, together with recent reports from other groups, suggest that simple prebiotic peptides could have supported the ancient RNA‐based replication system, gradually folded into RNA‐binding proteins, and eventually evolved into complex proteins like RNA polymerase. [ABSTRACT FROM AUTHOR]

Peptides have essential structural and catalytic functions in living organisms. The formation of peptides requires the overcoming of thermodynamic and kinetic barriers. In recent years, various formation scenarios that may have occurred during the origin of life have been investigated, including iron(III)‐catalyzed condensations. However, iron(III)‐catalysts require elevated temperatures and the catalytic activity in peptide bond forming reactions is often low. It is likely that in an anoxic environment such as that of the early Earth, reduced iron compounds were abundant, both on the Earth's surface itself and as a major component of iron meteorites. In this work, we show that reduced iron activated by acetic acid mediates efficiently peptide formation. We recently demonstrated that, compared to water, liquid sulfur dioxide (SO2) is a superior reaction medium for peptide formations. We thus investigated both and observed up to four amino acid/peptide coupling steps in each solvent. Reaction with diglycine (G2) formed 2.0 % triglycine (G3) and 7.6 % tetraglycine (G4) in 21 d. Addition of G3 and dialanine (A2) yielded 8.7 % G4. Therefore, this is an efficient and plausible route for the formation of the first peptides as simple catalysts for further transformations in such environments. [ABSTRACT FROM AUTHOR]

The tricarboxylic acid (TCA) or Krebs cycle, which takes place in prokaryotic cells and in the mitochondria of eukaryotic cells, is central to life on Earth and participates in key events such as energy production and anabolic processes. Despite its relevance, it is not perceived as tightly regulated compared to other key metabolisms such as glycolysis/gluconeogenesis. A better understanding of the functioning of the TCA cycle is crucial due to mitochondrial function impairment in several diseases, especially those that occur with neurodegeneration. This article revisits what is known about the regulation of the Krebs cycle and hypothesizes the need for large‐scale, rapid regulation of TCA cycle enzyme activity. Evidence of mitochondrial enzyme activity regulation by activation/deactivation of protein kinases and phosphatases exists in the literature. Apart from indirect regulation via G protein‐coupled receptors (GPCRs) at the cell surface, signaling upon activation of GPCRs in mitochondrial membranes may lead to a direct regulation of the enzymes of the Krebs cycle. Hormonal‐like regulation by posttranscriptional events mediated by activable kinases and phosphatases deserve proper assessment using isolated mitochondria. Also see the video abstract here: https://youtu.be/aBpDSWiMQyI [ABSTRACT FROM AUTHOR]

Humans are remaking the planet, with the planetary human imprint so profound that all planetary systems are being changed: the atmosphere, the hydrosphere and cryosphere (water and ice), the lithosphere (Earth's crust), and the biosphere (the community of life). The changes are so deep and far reaching that a new geological epoch, the first effected by humans, has set in, the Anthropocene. It succeeds the only geological epoch human civilizations have known, the late Holocene. The tattoo of the Holocene, climate stability, is replaced by climate volatility, mass eco‐social uncertainty, and extinction. Because the Anthropocene is itself the outcome of cumulative human choices, everything in response also turns on ethics. In this case, that entails rethinking and reforming human responsibility. This essay pursues that, after making the case for climate and the Anthropocene as a new prism for Religious Ethics, one that changes the work of Religious Ethics itself. [ABSTRACT FROM AUTHOR]

Chinese traditional bioethics is based on the life origin theory of "Qi (vital force) permeates everything under heaven", the attitude towards life theory of "loving people" and "loving things", and the life transcendence theory of "eternity" and "immortality". The life origin theory answers the question of how life comes into being, which is the basis for exploring the mystery of life. The attitude towards life theory gives answers to the question of how to treat life properly and establishes the basic requirements and criteria for treating life. The life transcendence theory responds to the question of how to make life more meaningful. Those three thoughts support each other and explain each other with the inner logical band between these three basic thoughts, and tentatively offers a reasonable way for the reconstruction of traditional Chinese bioethics, which can be a special theoretical resource for today's bioethical research. [ABSTRACT FROM AUTHOR]

Water‐rock reactions liberate bioavailable energy, a necessary condition for chemotrophic habitability and origins of life. The major minerals of ultramafic (UM) rocks: olivine (ol), orthopyroxene (opx), and clinopyroxene (cpx), are of particular astrobiological interest as they are widespread in the solar system and known to produce significant quantities of H2 during aqueous alteration (serpentinization). H2 yields energy to life when oxidized by chemical species common to planetary fluids and is the most deeply rooted metabolite in Earth's phylogenetic tree. However, while field observations and calculations have corroborated the H2‐generating potential of UM rocks, specific formation pathways remain elusive, as the alteration assemblages in natural samples contain substantial heterogeneity. Here we show that variable UM compositions, temperature (T), and the mass ratio of Earth's seawater to rock (w/r) conspire to segregate alteration systems into those that produce supra‐mmol H2, and those that produce sub‐µmol H2. The oxidation of UM Fe(II) to Fe(III) provides the electrons necessary to reduce H2O to H2. However, the Fe(III)‐bearing phases that facilitate this process form together with more abundant phases competing for the same elements, including Ca, Si, and Fe(II). As a result, H2 abundance is determined by non‐redox‐active elements. Maximum H2 at high T requires low Si and is generally supported by Fe(III)‐serpentine and magnetite formation. Andradite formation, which stores Fe(III) but requires elevated Ca abundance, throttles up H2 production as T decreases in aging systems. These conditions are achieved in ol‐ and cpx‐rich rocks while opx‐rich rocks sequester less Fe(III), producing less H2. Plain Language Summary: Rocks near the surface of a planet commonly interact with water, such as seawater. This interaction can cause chemical reactions that produce hydrogen, which single celled organisms can consume to drive their metabolism. In this study, we use thermodynamic techniques to calculate the amount of hydrogen that is produced when a rock type common to the Earth and our solar system (ultramafic rock) interacts with seawater, across changes in temperature, changes in the physical ratio of seawater to rock, and changes in the ultramafic composition. These are all fundamental variables that natural systems sustaining diverse ecosystems explore. We find that some ultramafic rocks (those enriched in the mineral orthopyroxene) are unlikely to benefit life, whereas other ultramafic compositions (those enriched in the minerals olivine and/or clinopyroxene) produce large quantities of hydrogen. We resolve and discuss the mechanism by which this dichotomy emerges. Key Points: Seawater‐hosted serpentinizing systems partition into those that produce >mmol H2, and those that produce <μmol H2, given Si, Ca, and FeH2 production is highly heterogeneous with respect to ultramafic compositionThe formation of magnetite + brucite does not necessarily indicate large H2 production [ABSTRACT FROM AUTHOR]

This document is a citation for the 2021 Barringer Award given to G. Osinski for his contributions to the field of impact studies. Osinski's research has focused on hypervelocity impact processes and their products, particularly in relation to impact melt-bearing lithologies. He has made significant discoveries regarding the nature of impact melt rocks and the composition of suevite deposits. Osinski has also proposed a modified working hypothesis for ejecta emplacement on terrestrial planets and has explored the relationship between impacts and the biosphere. In addition to his research, Osinski has been actively involved in public outreach, developing programs and initiatives to educate and engage the wider community. Overall, Osinski's work has made major contributions to our understanding of impact cratering processes and their effects. [Extracted from the article]

H2‐producing, submarine hydrothermal vents present a plausible environment for the prebiotic synthesis of the first organic compounds at the emergence of life. Geochemical CO2 reduction at these vent systems harbors similarity to the ancient, biochemical acetyl‐CoA pathway of CO2 fixation in modern autotrophs. Both pathways involve catalytic transformations with transition metals as active centers. This concept article provides some insight about origins of life, mineral‐catalyzed CO2 reduction, and its correlation to the enzymatic pathway by focusing on key studies. [ABSTRACT FROM AUTHOR]

The prebiotic generation of sugars in the context of origins of life studies is of considerable interest. Among the important intramolecular processes of sugars are carbonyl migrations and accompanying epimerizations. Herein we describe the carbonyl migration‐epimerization process occurring down the entire carbon chain of chirally pure d‐tetroses sugars under mild conditions. Employing chirally pure 1‐13C‐erythrose, 4‐13C‐erythrose and 1‐13C‐threose, we (1) identify all the species formed as the carbonyl migrates down the four‐carbon chain and (2) assess the rates associated with the production of each of these species. Competing aldol reactions and oxidative fragmentation processes were also observed. Further observations of self‐condensation of glycolaldehyde mainly yielding 2‐keto‐hexoses (sorbose and tagatose) and tetrulose also provides a basis for understanding the effect of carbonyl migrations on the product distribution in plausible prebiotic scenarios. [ABSTRACT FROM AUTHOR]

Calculating the phosphorus (P) budget of the bulk silicate Earth (BSE) is necessary to understand the global P cycle and the origin and evolution of life. Covariations of P and neodymium (Nd) contents suggest that P is 1.1–1.4 times more incompatible than Nd during mantle melting and magmatic differentiation. As such, the P/Nd ratios of mantle sources can be estimated using inverse modeling, and the P budget of the BSE can be calculated from the P/Nd ratios of the continental crust, mid‐ocean ridge basalts (MORBs), and ocean island basalts (OIBs). The P/Nd ratios for the MORB and OIB mantle sources and continental crust are 62.5 ± 0.8 (2σm), 57.0 ± 0.5 (2σm), and 28.4 ± 12.0 (2σm), respectively. These reservoirs have different P/Nd ratios due to subduction, magmatic differentiation, and mineralogy. Subduction can significantly affect the global P and Nd cycles. Magmatic differentiation, especially in the continental crust, may redistribute P by changing the contents of garnet, apatite, and other minerals. The fractional contributions of these global reservoirs suggest the modern BSE has a P/Nd ratio of 57.7 ± 3.0 (2σm), equating to ∼3.1 × 1020 kg of P in the BSE. Plain Language Summary: P is an essential nutrient element that underpins biological evolution. As such, knowledge of how P is distributed in different reservoirs of the bulk silicate Earth (BSE) allows us to understand the biosphere and Earth system. We estimated the P budget of the BSE based on the P/Nd ratio using geochemical data for the continental crust, mid‐ocean ridge basalts (MORBs), and ocean island basalts (OIBs). The fractional contributions of continental crust and MORB and OIB mantle sources with different P/Nd ratios indicate the P budget of the modern BSE is ∼3.1 × 1020 kg. In addition, the mantle contains >95% of the P budget of the BSE. This latest estimate could lead to a better understanding of the geochemical differentiation of the silicate Earth, the distribution of P in nature, and the present‐day Earth system. Key Points: The mid‐ocean ridge basalt and ocean island basalt sources and continental crust have different P/Nd ratiosThe different P/Nd ratios may be due to mineralogy, magmatic differentiation, and subductionAn updated estimate of the P/Nd ratio indicates the modern silicate Earth contains about 3.1 × 1020 kg of P [ABSTRACT FROM AUTHOR]