Chemical evolution toward the origin of life

2007 ◽  
Vol 79 (12) ◽  
pp. 2101-2117 ◽  
Author(s):  
Daniel Fitz ◽  
Hannes Reiner ◽  
Bernd Michael Rode

Numerous hypotheses about how life on earth could have started can be found in the literature. In this article, we give an overview about the most widespread ones and try to point out which of them might have occurred on the primordial earth with highest probability from a chemical point of view. The idea that a very early stage of life was the "RNA world" encounters crucial problems concerning the formation of its building blocks and their stability in a prebiotic environment. Instead, it seems much more likely that a "peptide world" originated first and that RNA and DNA took up their part at a much later stage. It is shown that amino acids and peptides can be easily formed in a realistic primordial scenario and that these biomolecules can start chemical evolution without the help of RNA. The origin of biohomochirality seems strongly related to the most probable formation of the first peptides via the salt-induced peptide formation (SIPF) reaction.

2017 ◽  
Vol 4 (11) ◽  
pp. 170141 ◽  
Author(s):  
Rowena Ball ◽  
John Brindley

In a major extension of previous work, we model the putative hydrothermal rock pore setting for the origin of life on Earth as a series of coupled continuous flow units (the toy train ). Perfusing through this train are reactants that set up thermochemical and pH oscillations, and an activated nucleotide that produces monomer and dimer monophosphates. The dynamical equations that model this system are thermally self-consistent. In an innovative step that breaks some new ground, we build stochasticity of the inputs into the model. The computational results infer various constraints and conditions on, and insights into, chemical evolution and the origin of life and its physical setting: long, interconnected porous structures with longitudinal non-uniformity would have been favourable, and the ubiquitous pH dependences of biology may have been established in the prebiotic era. We demonstrate the important role of Gaussian fluctuations of the inputs in driving polymerization, evolution and diversification. In particular, we find that the probability distribution of the resulting output fluctuations is left-skewed and right-weighted (the loaded dice ), which could favour chemical evolution towards a living RNA world. We tentatively name this distribution ‘Goldilocks’. These results also vindicate the general approach of constructing and running a simple model to learn important new information about a complex system.


2017 ◽  
Vol 01 (02) ◽  
pp. 121-131 ◽  
Author(s):  
Jack W. Szostak

To understand the origin of life on Earth, and to evaluate the potential for life on exoplanets, we must understand the pathways that lead from chemistry to biology. Recent experiments suggest that a chemically rich environment that provides the building blocks of membranes, nucleic acids and peptides, along with sources of chemical energy, could result in the emergence of replicating, evolving cells. The broad scope of synthetic chemistry suggests that it may be possible to design and construct artificial life forms based upon a very different biochemistry than that of existing biology.


2015 ◽  
Vol 87 (2) ◽  
pp. 205-218 ◽  
Author(s):  
Albert C. Fahrenbach

AbstractThe nonenzymatic synthesis of nucleic acids, in particular, RNA, and the template-directed synthesis of artificial organic molecules, such as macrocycles, catenanes and rotaxanes, have both undergone significant development since the last half of the 20th century. The intersection of these two fields affords insights into how template effects can lead to information copying and storage at the molecular level. Mechanistic examples of model template-directed RNA replication experiments as well as those for totally artificial organic template-directed syntheses will be discussed. The fact that templates typically bind to their reacted products more tightly than their unreacted substrates may be a mechanistic feature necessary to store information in the form of nucleic acids. Understanding the mechanisms of nonenzymatic RNA synthesis is not only essential for testing the RNA world hypothesis in the context of the origin of life on Earth and other planetary bodies, but may one day afford chemists the insights to construct their own artificial molecular replicators.


Life ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 39 ◽  
Author(s):  
Satoru Nakashima ◽  
Yoko Kebukawa ◽  
Norio Kitadai ◽  
Motoko Igisu ◽  
Natsuki Matsuoka

In 2001, the first author (S.N.) led the publication of a book entitled “Geochemistry and the origin of life” in collaboration with Dr. Andre Brack aiming to figure out geo- and astro-chemical processes essential for the emergence of life. Since then, a great number of research progress has been achieved in the relevant topics from our group and others, ranging from the extraterrestrial inputs of life’s building blocks, the chemical evolution on Earth with the aid of mineral catalysts, to the fossilized records of ancient microorganisms. Here, in addition to summarizing these findings for the origin and early evolution of life, we propose a new hypothesis for the generation and co-evolution of photosynthesis with the redox and photochemical conditions on the Earth’s surface. Besides these bottom-up approaches, we introduce an experimental study on the role of water molecules in the life’s function, focusing on the transition from live, dormant, and dead states through dehydration/hydration. Further spectroscopic studies on the hydrogen bonding behaviors of water molecules in living cells will provide important clues to solve the complex nature of life.


2016 ◽  
Vol 16 (2) ◽  
pp. 105-113 ◽  
Author(s):  
Savio Torres de Farias ◽  
Francisco Prosdocimi

AbstractThe last universal common ancestor (LUCA) has been considered as the branching point on which Bacteria, Archaea and Eukaryotes have diverged. However, the increased information relating to viruses’ genomes and the perception that many virus genes do not have homologs in other organisms opened a new discussion. Based on these facts, there has emerged the idea of an early LUCA that should be moved further into the past to include viruses, implicating that life should have originated before the appearance of cellular life forms. Another point of view from advocates of the RNA-world suggests that the origin of life happened a long time before organisms were capable of organizing themselves into cellular entities. Relevant data about the origin of ribosomes indicate that the catalytic unit of the large ribosomal subunit is what should actually be considered as the turning point that separated chemistry from biology. Other researchers seem to think that a tRNA was probably some sort of a strange attractor on which life has originated. Here we propose a theoretical synthesis that tries to provide a crosstalk among the theories and define important points on which the origin of life could have been originated and made more complex, taking into account gradualist assumptions. Thus, discussions involving the origin of biological activities in the RNA-world might lead into a world of progenotes on which viruses have been taken part until the appearance of the very first cells. Along this route of complexification, we identified some key points on which researchers may consider life as an emerging principle.


Author(s):  
Hannah Mahoney

When, where, and how did life on Earth originate? The origin of life problem involves multiple scientific disciplines and has spanned multiple decades. It can be summarized into three stages: (1) the origin of biological monomers, (2) the origin of biological polymers, and (3) the emergence and evolution of cells. While highly speculative, the connections between these stages are theorized by attempting to determine the geochemical situations which could have driven chemical evolution and allow for the emergence of specific chemical functions of biological systems. This review summarizes reported findings relevant to the early Earth environment and the main theories in the origin of life subject. Specific focus is placed on the metabolism first, RNA world, and compartmentalization first theories as they are involved in the origin of life paradox. The review then discusses submarine hydrothermal vents as a possible location for which life could have occurred. Understanding of information pertaining to the origin of life is important as it allows for advancement and discoveries in other fields of science and medicine. Overall, the aim of this review is to display the relevant information about the origin of life theory and highlight the importance of future research.


2013 ◽  
Vol 23 (1) ◽  
pp. 213-229 ◽  
Author(s):  
Dariusz Myszor ◽  
Krzysztof A. Cyran

In this article, we analyse the process of the emergence of RNA polynucleotides located in an enclosed environment, at an early stage of the RNA world. Therefore we prepared a mathematical model, composed of a set of differential equations, which simulates the behaviour of an early biological system bounded by a protocell membrane. There is evidence that enclosed environments were available on the primordial Earth. There are also experimental proofs that RNA strands can develop in these formations. The proposed model allows analysis of the influence of membrane permeability on the composition of internal material. It takes into account phenomena that lead to the elongation of an RNA strand (ligation), fission of molecules (phosphodiester bond breakage) and replication of polynucleotides. Results obtained from the model point out that the existence of protocells might support concentration of material and creation of longer molecules.


Elements ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 261-265 ◽  
Author(s):  
Yoshihiro Furukawa ◽  
Takeshi Kakegawa

According to the RNA World hypothesis, ribonucleic acid (RNA) played a critical role in the origin of life. However, ribose, an essential component of RNA, is easily degraded: finding a way to stabilize it is critical to the viability of the hypothesis. Borate has been experimentally shown to have a strong affinity for ribose, and, thus, could have protected ribose from degradation in the formose reaction, a potential process for prebiotic ribose formation. Accumulation of borate on Hadean Earth (prior to ~4,000 Ma) might have been a key step in the chemical evolution of the biotic sugar. Proto-arcs are suggested as a geological setting sufficiently rich in borate to stabilize ribose during the Hadean.


2008 ◽  
Vol 4 (S255) ◽  
pp. 330-335
Author(s):  
Yutaka Komiya ◽  
Takuma Suda ◽  
Asao Habe ◽  
Masayuki Fujimoto

AbstractExtremely metal-poor (EMP) stars are thought to be formed in the low-mass protogalaxies as building blocks of the Milky Way and can be probes to investigate the early stage of galaxy formation and star formation in the early universe. We study the formation history of EMP stars in the Milky Way halo using a new model of chemical evolution based on the hierarchical theory of the galaxy formation. We construct the merging history of the Milky Way halo based on the extended Press-Schechter formalism, and follow the star formation and chemical evolution along the merger tree. The abundance trends and number of low-mass stars predicted in our model are compared with those of observed EMP stars. Additionally, in order to clarify the origin of hyper metal poor stars, we investigate the change of the surface metal abundances of stars by accretion of interstellar matter. We also investigate the pre-enrichment of intergalactic matter by the first supernovae.


Sign in / Sign up

Export Citation Format

Share Document