Origin Of Life Research Articles

Gamma-Ray-Induced Amino Acid Formation in Aqueous Small Bodies in the Early Solar System.

Carbonaceous chondrites contain life's essential building blocks, including amino acids, and their delivery of organic compounds would have played a key role in life's emergence on Earth. Aqueous alteration of carbonaceous chondrites is a widespread process induced by the heat produced by radioactive decay of nuclides like 26Al. Simple ubiquitous molecules like formaldehyde and ammonia could produce various organic compounds, including amino acids and complex organic macromolecules. However, the effects of radiation on such organic chemistry are unknown. Hence, the effects of gamma rays from radioactive decays on the formation of amino acids in meteorite parent bodies are demonstrated here. We discovered that gamma-ray irradiation of aqueous formaldehyde and ammonia solutions afforded a variety of amino acids. The amino acid yields had a linear relationship with the total gamma-ray dose but were unaffected by the irradiation dose rates. Given the gamma-ray production rates in the meteorite parent bodies, we estimated that the production rates were reasonable compared to amino acid abundances in carbonaceous chondrites. Our findings indicate that gamma rays may contribute to amino acid formation in parent bodies during aqueous alteration. In this paper, we propose a new prebiotic amino acid formation pathway that contributes to life's origin.

A Nonenzymatic Analog of Pyrimidine Nucleobase Biosynthesis

AbstractMetabolic theories for the origin of life posit that inorganic catalysts enabled self‐organized chemical precursors to the pathways of metabolism, including those that make genetic molecules. Recently, experiments showing nonenzymatic versions of a number of core metabolic pathways have started to support this idea. However, experimental demonstrations of nonenzymatic reaction sequences along the de novo ribonucleotide biosynthesis pathways are limited. Here we show that all three reactions of pyrimidine nucleobase biosynthesis that convert aspartate to orotate proceed at 60 °C without photochemistry under aqueous conditions in the presence of metals such as Cu2+and Mn4+. Combining reactions into one‐pot variants is also possible. Life may not have invented pyrimidine nucleobase biosynthesis from scratch, but simply refined existing nonenzymatic reaction channels. This work is a first step towards uniting metabolic theories of life's origin with those centered around genetic molecules.

A material-based panspermia hypothesis: The potential of polymer gels and membraneless droplets.

The Panspermia hypothesis posits that either life's building blocks (molecular Panspermia) or life itself (organism-based Panspermia) may have been interplanetarily transferred to facilitate the origins of life (OoL) on a given planet, complementing several current OoL frameworks. Although many spaceflight experiments were performed in the past to test for potential terrestrial organisms as Panspermia seeds, it is uncertain whether such organisms will likely "seed" a new planet even if they are able to survive spaceflight. Therefore, rather than using organisms, using abiotic chemicals as seeds has been proposed as part of the molecular Panspermia hypothesis. Here, as an extension of this hypothesis, we introduce and review the plausibility of a polymeric material-based Panspermia seed (M-BPS) as a theoretical concept, where the type of polymeric material that can function as a M-BPS must be able to: (1) survive spaceflight and (2) "function", i.e., contingently drive chemical evolution toward some form of abiogenesis once arriving on a foreign planet. We use polymeric gels as a model example of a potential M-BPS. Polymeric gels that can be prebiotically synthesized on one planet (such as polyester gels) could be transferred to another planet via meteoritic transfer, where upon landing on a liquid bearing planet, can assemble into structures containing cellular-like characteristics and functionalities. Such features presupposed that these gels can assemble into compartments through phase separation to accomplish relevant functions such as encapsulation of primitive metabolic, genetic and catalytic materials, exchange of these materials, motion, coalescence, and evolution. All of these functions can result in the gels' capability to alter local geochemical niches on other planets, thereby allowing chemical evolution to lead to OoL events.

Undefining life's biochemistry: implications for abiogenesis.

In the mid-twentieth century, multiple Nobel Prizes rewarded discoveries of a seemingly universal set of molecules and interactions that collectively defined the chemical basis for life. Twenty-first-century science knows that every detail of this Central Dogma of Molecular Biology can vary through either biological evolution, human engineering (synthetic biology) or both. Clearly the material, molecular basis of replicating, evolving entities can be different. There is far less clarity yet for what constitutes this set of possibilities. One approach to better understand the limits and scope of moving beyond life's central dogma comes from those who study life's origins. RNA, proteins and the genetic code that binds them each look like products of natural selection. This raises the question of what step(s) preceded these particular components? Answers here will clarify whether any discrete point in time or biochemical evolution will objectively merit the label of life's origin, or whether life unfolds seamlessly from the non-living universe.

Benesh Joseph.

"I am waiting for the day when someone will discover the mystery of life's origin … My biggest motivation is the excitement of making a new observation …" Find out more about Benesh Joseph in his Introducing … Profile.

Benesh Joseph

Abstract “I am waiting for the day when someone will discover the mystery of life's origin … My biggest motivation is the excitement of making a new observation …” Find out more about Benesh Joseph in his Introducing … Profile.

Acid-Catalyzed RNA-Oligomerization from 3',5'-cGMP.

The assembly of ancient informational polymers from nucleotide precursors is the central challenge of life's origin on our planet. Among the possible solutions, dry polymerization of 3’,5’‐cyclic guanosine monophosphate (3’,5’‐cGMP) has been proposed as a candidate to create oligonucleotides of 15–20 units in length. However, the reported sensitivity of the reaction to the presence of cations raised questions of whether this chemistry could be relevant in a geological context. The experiments in this study show that the presence of cations is not restrictive as long as the reaction is conducted in an acidic environment, in contrast to previous reports that suggested optimal conditions at pH 9.

Self-reproducing catalytic micelles as nanoscopic protocell precursors.

Protocells at life's origin are often conceived as bilayer-enclosed precursors of life, whose self-reproduction rests on the early advent of replicating catalytic biopolymers. This Perspective describes an alternative scenario, wherein reproducing nanoscopic lipid micelles with catalytic capabilities were forerunners of biopolymer-containing protocells. This postulate gains considerable support from experiments describing micellar catalysis and autocatalytic proliferation, and, more recently, from reports on cross-catalysis in mixed micelles that lead to life-like steady-state dynamics. Such results, along with evidence for micellar prebiotic compatibility, synergize with predictions of our chemically stringent computer-simulated model, illustrating how mutually catalytic lipid networks may enable micellar compositional reproduction that could underlie primal selection and evolution. Finally, we highlight studies on how endogenously catalysed lipid modifications could guide further protocellular complexification, including micelle to vesicle transition and monomer to biopolymer progression. These portrayals substantiate the possibility that protocellular evolution could have been seeded by pre-RNA lipid assemblies.

The Significance of The Mystery of Life's Origin

The Significance of The Mystery of Life's Origin

"Minimal metabolism": A key concept to investigate the origins and nature of biological systems.

The systems view on life and its emergence from complex chemistry has remarkably increased the scientific attention on metabolism in the last two decades. However, during this time there has not been much theoretical discussion on what constitutes a metabolism and what role it actually played in biogenesis. A critical and updated review on the topic is here offered, including some references to classical models from last century, but focusing more on current and future research. Metabolism is considered as intrinsically related to the living but not necessarily equivalent to it. More precisely, the idea of "minimal metabolism", in contrast to previous, top-down conceptions, is formulated as a heuristic construct, halfway between chemistry and biology. Thus, rather than providing a complete or final characterization of metabolism, our aim is to encourage further investigations on it, particularly in the context of life's origin, for which some concrete methodological suggestions are provided. Also see the video abstract here: https://youtu.be/DP7VMKk2qpA.

A Corollary of the Conant-Ashby Theorem Applied to Abiogenesis

From the Conant-Ashby theorem about the "good regulator" is possible to derive a corollary about the origin of life (OOL). This corollary introduces the concept of "good constructor." Thenit is shown as nature, seen as a material system ruled by the laws of physics, cannot be a "good constructor" of the basic machinery necessary for a living cell. As a consequence OOL needs intelligent design.

Origin of Life on Mars: Suitability and Opportunities.

Although the habitability of early Mars is now well established, its suitability for conditions favorable to an independent origin of life (OoL) has been less certain. With continued exploration, evidence has mounted for a widespread diversity of physical and chemical conditions on Mars that mimic those variously hypothesized as settings in which life first arose on Earth. Mars has also provided water, energy sources, CHNOPS elements, critical catalytic transition metal elements, as well as B, Mg, Ca, Na and K, all of which are elements associated with life as we know it. With its highly favorable sulfur abundance and land/ocean ratio, early wet Mars remains a prime candidate for its own OoL, in many respects superior to Earth. The relatively well-preserved ancient surface of planet Mars helps inform the range of possible analogous conditions during the now-obliterated history of early Earth. Continued exploration of Mars also contributes to the understanding of the opportunities for settings enabling an OoL on exoplanets. Favoring geochemical sediment samples for eventual return to Earth will enhance assessments of the likelihood of a Martian OoL.

Mechanochemistry at the Origins of Life?

Mechanochemistry at the Origins of Life?

Dynamic lipid aptamers: non-polymeric chemical path to early life.

A widespread dogma asserts that life could not have emerged without biopolymers - RNA and proteins. However, the widely acknowledged implausibility of a spontaneous appearance and proliferation of these complex molecules in primordial messy chemistry casts doubt on this scenario. A proposed alternative is "Lipid-First", based on the evidence that lipid assemblies may spontaneously emerge in heterogeneous environments, and are shown to undergo growth and fission, and to portray autocatalytic self-copying. What seems undecided is whether lipid assemblies have protein-like capacities for stereospecific interactions, a sine qua non of life processes. This Viewpoint aims to alleviate such doubts, pointing to growing experimental evidence that lipid aggregates possess dynamic surface configurations capable of stereospecific molecular recognition. Such findings help support a possible key role of lipids in seeding life's origin.

世界自然遗产地陆生藻类物种多样性比较研究

藻类是真核生物进化、植物起源与进化、生物地理学研究的良好材料，研究藻类物种多样性对理解生命起源与早期进化，探明地球地质地貌演化有着非常重要的意义。以两世界自然遗产地施秉云台山白云岩喀斯特、赤水丹霞的陆生藻类为研究对象，通过G-F多样性指数、Jaccard相似性系数、Bray-Curtis矩阵比较分析了不同地质地貌的两世界自然遗产地陆生藻类的物种多样性及种组特征，结果如下：（1）两地陆生藻类丰富，均以蓝藻为优势，共有优势科为色球藻科Chroococcaceae、颤藻科Oscillatoriaceae，施秉云台山还具伪枝藻科Scytonemataceae、念珠藻科Nostocaceae优势，优势属为粘球藻属Gloeocapsa、色球藻属Chroococcus，赤水丹霞仅以粘球藻属Gloeocapsa为优势。（2）施秉云台山G-F多样性指数高于赤水丹霞。（3）两地陆生藻类泛热带成分明显，施秉云台山中国特有成分较赤水丹霞丰富；两地科、属、种相似性系数依次为：56.25%、44.05%、37.62%，科的相似性达到中度水平，与同纬度范围其它地区的Bray-Curtis矩阵聚类结果显示不同地质地貌的两地首先聚为一类。从陆生藻类多样性组成上，初步反映两世界自然遗产地的地质历史、地层岩性及地理位置的异同。;Algae have been regarded as very useful materials for the research of eukaryote evolution, plant origin and evolution, and biogeographic changes. Thus, their diversity profiles are essential in understanding life's origin and early evolutionary development and exploring the earth's geology and geomorphology structure. We studied the terrestrial algae of Shibing Yuntai Mountain (SYM) and Chishui Danxia (CD) in Guizhou, the two world natural heritage sites in China representing dolomite karst and danxia landforms, respectively. G-F diversity index, similarity index, and Bray Curtis were used to compare their species composition. The results indicate that:(1) the algae are abundant in both heritage sites, featured with dominant cyanobacteria species, especially the families of Chroococcaceae and Oscillatoriaceae. The SYM, however, is rich in Scytonemataceae and Nostocaceae, with more abundance of Gloeocapsa and Chroococcus, which is different from CD with abundant genus Gloeocapsa. (2) SYM's G-F diversity indices are greater than CD's. Thus, the species diversity of SYM is higher than that of CD. This phenomenon may be related to the factor that the alga-promoting effect of the dolomite soil and the alga-suppressing effect of the red layer soil containing rich Fe and Mn. The predominance of nitrogen-fixed cyanobacteria in Scytonemataceae and Nostocaceae reflects the dolomite karst's environmental characteristics:rich in calcium and magnesium but poor nutrition. The species of Gloeocapsa in CD are more abundant, which are related to the silicate minerals in sandstone, besides the dry and hot climate. (3) The algae analyzed in both sites have significantly tropical and subtropical compositions and are endemic to China, especially regarding SYM. The similarity coefficients of families, genera, and species between the two sites are 56.25%, 44.05%, and 37.62%. Family similarity reaches a moderate level. The Bray-Curtis results show that the two sites are clustered into the same category despite their different geological and geomorphological features. The shared similarity at family and genus levels of the algae implies that the two sites maybe have diverged from the same aquatic environments. However, the heterogeneity at the species level between the sites maybe have resulted from their different terrestrial geographic landscapes, which shaped the algae alternatively under natural selection and environmental adaptation principles. We find the characteristic algae that can prove the landform's development from different compositions of the existing algae at the two sites. Thus, this preliminary study integrally and systematically analyzes terrestrial algae's diversity, heterogeneity, and similarity, and geographic varieties in evolutionary development, stratigraphic lithology, and structure of the two heritage sites in China.

Projeto ENEM e a formação inicial de professores: a construção do conhecimento escolar em um subprojeto Biologia do PIBID

Trata-se de um estudo sobre o desenvolvimento do Projeto ENEM, no âmbito do subprojeto Biologia do PIBID, em uma escola pública no município de São Gonçalo, Rio de Janeiro, de 2018 a 2019. O estudo teve natureza qualitativa, tendo sido realizada a pesquisa-ação. Foram tomados como materiais empíricos observações, relatos e materiais didáticos produzidos neste período. Durante os anos de 2018 e 2019 houve o planejamento e desenvolvimento de aulas e materiais didáticos pelos licenciandos sobre temas frequentes no ENEM e vestibulares, tais como: vírus, bactérias, DNA, ecologia, genética mendeliana, origem da vida, evolução biológica, respiração celular, fotossíntese, fisiologia humana, morfologia vegetal, histologia e programas de saúde. Os estagiários destacaram a relevância do PIBID para a formação inicial docente e educação básica. Houve maior número de estudantes inscritos no ENEM e em vestibulares com aprovação em universidades públicas.

Macrobiont: Cradle for the Origin of Life and Creation of a Biosphere.

Although the cellular microorganism is the fundamental unit of biology, the origin of life (OoL) itself is unlikely to have occurred in a microscale environment. The macrobiont (MB) is the macro-scale setting where life originated. Guided by the methodologies of Systems Analysis, we focus on subaerial ponds of scale 3 to 300 m diameter. Within such ponds, there can be substantial heterogeneity, on the vertical, horizontal, and temporal scales, which enable multi-pot prebiotic chemical evolution. Pond size-sensitivities for several figures of merit are mathematically formulated, leading to the expectation that the optimum pond size for the OoL is intermediate, but biased toward smaller sizes. Sensitivities include relative access to nutrients, energy sources, and catalysts, as sourced from geological, atmospheric, hydrospheric, and astronomical contributors. Foreshores, especially with mudcracks, are identified as a favorable component for the success of the macrobiont. To bridge the gap between inanimate matter and a planetary-scale biosphere, five stages of evolution within the macrobiont are hypothesized: prebiotic chemistry → molecular replicator → protocell → macrobiont cell → colonizer cell. Comparison of ponds with other macrobionts, including hydrothermal and meteorite settings, allows a conclusion that more than one possible macrobiont locale could enable an OoL.

On the Origins of Life

The perspective Brian Miller and Jeremy England bring to their essay on the origins of life is that of physics. Yet the origins of life are, ultimately, chemical and biological.

Searching high and low for the origins of life

Searching high and low for the origins of life

Molecular reactions at aqueous interfaces.

This Review aims to critically analyse the emerging field of chemical reactivity at aqueous interfaces. The subject has evolved rapidly since the discovery of the so-called 'on-water catalysis', alluding to the dramatic acceleration of reactions at the surface of water or at its interface with hydrophobic media. We review critical experimental studies in the fields of atmospheric and synthetic organic chemistry, as well as related research exploring the origins oflife, to showcase the importance of this phenomenon. The physico-chemical aspects of these processes, such as the structure, dynamics and thermodynamics of adsorption and solvation processes at aqueous interfaces, are also discussed. We also present the basic theories intended to explain interface catalysis, followed by the results of advanced ab initio molecular-dynamics simulations. Although some topics addressed here have already been the focus of previous reviews, we aim at highlighting their interconnection across diverse disciplines, providing a common perspective that would help us to identify the most fundamental issues still incompletely understood in this fast-moving field.