scholarly journals Towards open-ended evolution in self-replicating molecular systems

2017 ◽  
Vol 13 ◽  
pp. 1189-1203 ◽  
Author(s):  
Herman Duim ◽  
Sijbren Otto
Keyword(s):  
Origin Of Life ◽  
De Novo ◽  
Building Blocks ◽  
Full Understanding ◽  
Molecular Systems ◽  
Form Of Life ◽  
Recent Advances ◽  
Molecular Building Blocks ◽  
Minimal Form ◽  
The Origin Of Life

In this review we discuss systems of self-replicating molecules in the context of the origin of life and the synthesis of de novo life. One of the important aspects of life is the ability to reproduce and evolve continuously. In this review we consider some of the prerequisites for obtaining unbounded evolution of self-replicating molecules and describe some recent advances in this field. While evolution experiments involving self-replicating molecules have shown promising results, true open-ended evolution has not been realized so far. A full understanding of the requirements for open-ended evolution would provide a better understanding of how life could have emerged from molecular building blocks and what is needed to create a minimal form of life in the laboratory.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

General discussion after session V

1988 ◽  
Vol 325 (1587) ◽  
pp. 611-618 ◽  
Keyword(s):  
Origin Of Life ◽  
Time Perspective ◽  
Applied Mathematics ◽  
Building Blocks ◽  
Living Systems ◽  
Organic Chemical ◽  
General Terms ◽  
The Earth ◽  
The Origin Of Life ◽  
Emergence Of Life

N. C. Wickramasinghe ( Department of Applied Mathematics and Astronomy, University College, Cardiff, U. K. ). The question of the origin of life is, of course, one of the most important scientific questions and it is also one of the most difficult. One is inevitably faced here with a situation where there are very few empirical facts of direct relevance and perhaps no facts relating to the actual transition from organic material to material that can even remotely be described as living. The time perspective of events that relate to this problem has already been presented by Dr Chang. Uncertainty still persists as to the actual first moment of the origin or the emergence of life on the Earth. At some time between 3800 and 3300 Ma BP the first microscopic living systems seem to have emerged. There is a definite moment in time corresponding to a sudden appearance of cellular-type living systems. Now, traditionally the evolution of carbonaceous compounds which led to the emergence of life on Earth could be divided into three principal steps and I shall just remind you what those steps are. The first step is the production of chemical building blocks that lead to the origin of the organic molecules necessary as a prerequisite for the evolution of life. Step two can be described in general terms as prebiotic evolution, the arrangement of these chemical units into some kind of sequence of precursor systems that come almost up to life but not quite; and then stage three is the early biological evolution which actually effects the transition from proto-cellular organic-type forms into truly cellular living systems. The transition is from organic chemistry, prebiotic chemistry to biochemistry. Those are the three principal stages that have been defined by traditional workers in the field, the people who, as Dr Chang said, have had the courage to make these queries and attempt to answer them. Ever since the classic experiments where organic materials were synthesized in the laboratory a few decades back, it was thought that the first step, the production of organic chemical units, is important for the origin of life on the Earth, and that this had to take place in some location on the Earth itself.

scholarly journals An optimal degree of physical and chemical heterogeneity for the origin of life?

2011 ◽  
Vol 366 (1580) ◽  
pp. 2894-2901 ◽  
Author(s):  
Jack W. Szostak
Keyword(s):  
Nucleic Acid ◽  
Origin Of Life ◽  
Self Assembly ◽  
Building Blocks ◽  
Reaction Products ◽  
Amphiphilic Molecules ◽  
Essential Components ◽  
The Origin Of Life ◽  
Chemical Inputs ◽  
Physical And Chemical

The accumulation of pure, concentrated chemical building blocks, from which the essential components of protocells could be assembled, has long been viewed as a necessary, but extremely difficult step on the pathway to the origin of life. However, recent experiments have shown that moderately increasing the complexity of a set of chemical inputs can in some cases lead to a dramatic simplification of the resulting reaction products. Similarly, model protocell membranes composed of certain mixtures of amphiphilic molecules have superior physical properties than membranes composed of single amphiphiles. Moreover, membrane self-assembly under simple and natural conditions gives rise to heterogeneous mixtures of large multi-lamellar vesicles, which are predisposed to a robust pathway of growth and division that simpler and more homogeneous small unilamellar vesicles cannot undergo. Might a similar relaxation of the constraints on building block purity and homogeneity actually facilitate the difficult process of nucleic acid replication? Several arguments suggest that mixtures of monomers and short oligonucleotides may enable the chemical copying of polynucleotides of sufficient length and sequence complexity to allow for the emergence of the first nucleic acid catalysts. The question of the origin of life may become less daunting once the constraints of overly well-defined laboratory experiments are appropriately relaxed.

scholarly journals Search for water and life's building blocks in the universe: A summary

2015 ◽  
Vol 11 (A29B) ◽  
pp. 436-440
Author(s):  
Edwin A. Bergin
Keyword(s):  
Origin Of Life ◽  
Radioactive Decay ◽  
Building Blocks ◽  
The Origin Of Life ◽  
The Right ◽  
The Universe

AbstractWater and organics need to be supplied to terrestrial worlds like our own to provide the essential compounds required for the origin of life. These molecules form initially during the earliest stages of stellar birth, are supplied by collapse to the planet-forming disk predominantly as ice, and may undergo significant processing during this collapse and within large planetesimals that are heated via radioactive decay. Water and organic carriers can be quite volatile, thus their survival as ices within rocks is not preordained. In this focus meeting our goal is to bring together astronomers, cosmochemists, planetary scientists, chemical physicists, and spectroscopists who each explore individual aspects of this problem. In this summary we discuss some of the main themes that appeared in the meeting. Ultimately, cross-field collaboration is needed to provide greater understanding of the likelihood that terrestrial worlds form with these key compounds readily available on their surfaces – and are hence habitable if present at the right distance from the star.

The first step from molecules to life: Formation of large random molecules acting as micro-environments

2020 ◽  
Author(s):  
Saibal Mitra
Keyword(s):  
Molecular Biology ◽  
Origin Of Life ◽  
Ultraviolet Irradiation ◽  
Building Blocks ◽  
Percolation Process ◽  
Von Neumann ◽  
Percolation Clusters ◽  
Period 2 ◽  
Interstellar Ice ◽  
The Origin Of Life

<p>The mathematician John von Neumann, through his work on universal constructors, discovered<br />a generalized version of the central dogma of molecular biology biology in the 1940s, long  <br />before the biological version had been discovered. While his discovery played no role in the  <br />development of molecular biology, we may benefit from a similar mathematical approach to find  <br />clues on the origin of life. This then involves addressing those problems in the field that  <br />do not depend on the details of organic chemistry. We can then consider a general set of  <br />models that describe machines capable of self-maintenance and self-replication formulated in  <br />terms of a set of building blocks and their interactions. </p> <p>The analogue of the origin of life problem is then to explain how one can get to such  <br />machines starting from a set of only building blocks. A fundamental obstacle one then faces  <br />is the limit on the complexity of low fidelity replicating systems, preventing building  <br />blocks from getting assembled randomly into low fidelity machines which can then improve due  <br />to natural selection [1]. A generic way out of this problem is for the entire ecosystem of  <br />machines to have been encapsulated in a micro-structure with fixed inner surface features  <br />that would have boosted the fidelity [2]. Such micro-structures could have formed as a result  <br />of the random assembly of building blocks, leading to so-called percolation clusters [2].</p> <p>This then leads us to consider how in the real world a percolation process involving the  <br />random assembly of organic molecules can be realized. A well studied process in the  <br />literature is the assembly of organic compounds in ice grains due to UV radiation and heating  <br />events [3,4,5]. This same process will also lead to the percolation process if it proceeds  <br />for a sufficiently long period [2].</p> <p>In this talk I will discuss the percolation process in more detail than has been done in [2],  <br />explaining how it leads to the necessary symmetry breakings such as the origin of chiral  <br />molecules needed to explain the origin of life.   </p> <p> </p> <p>[1] Eigen, M., 1971. Self-organization of matter and the evolution of biological  <br />macromolecules. Naturwissenschaften 58, 465-523.</p> <p>[2] Mitra, S., 2019. Percolation clusters of organics in interstellar ice grains as the  <br />incubators of life, Progress in Biophysics and Molecular Biology 149, 33-38.</p> <p>[3] Ciesla, F., and Sandford.,S., 2012. Organic Synthesis via Irradiation and Warming of Ice  <br />Grains in the Solar Nebula. Science 336, 452-454.</p> <p>[4] Muñoz Caro, G., et al., 2002. Amino acids from ultraviolet irradiation of interstellar ice  <br />analogues. Nature 416, 403-406.</p> <p>[5]  Meinert, C,., et al., 2016. Ribose and related sugars from ultraviolet irradiation of  <br />interstellar ice analogs. Science 352, 208-212.</p>

scholarly journals Synthesis by sunlight in relationship to the origin of life. Synthesis of formaldehyde from carbon dioxide and water by inorganic colloids acting as transformers of light energy

1913 ◽  
Vol 87 (593) ◽  
pp. 163-176 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Solar Energy ◽  
Origin Of Life ◽  
De Novo ◽  
Living Organism ◽  
British Association ◽  
Total Absence ◽  
Inorganic Matter ◽  
The Origin Of Life

At a discussion on the origin of life held by the joint sections of Zoology and Physiology of the British Association, at the Dundee Meeting, September, 1912, it was suggested by Moore that the first step towards the origin of life must have been the synthesis of organic matter from inorganic by the agency of inorganic colloids acting as transformers or catalysts for radiant solar energy. This suggestion was amplified and explained in a book written in November, 1912, by the same author. It is important to emphasise the point that in considering the origin of life in a world containing inorganic matter only, the nutrition of the first living structure on such a world must be carefully borne in mind. This observation is still true whether life is to be regarded as arising de novo on the planet, or as being borne there from some other planet as a germ from pre-existent life. No living organism such as a bacterium or mould which did not possess the power of transforming energy and of synthesising organic from inorganic matter could exist or flourish in total absence of pre-formed organic matter and must inevitably perish.

scholarly journals The Origin of Life on Earth and the Design of Alternative Life Forms

2017 ◽  
Vol 01 (02) ◽  
pp. 121-131 ◽  
Author(s):  
Jack W. Szostak
Keyword(s):  
Nucleic Acids ◽  
Origin Of Life ◽  
Artificial Life ◽  
Building Blocks ◽  
Life Forms ◽  
Chemical Energy ◽  
Synthetic Chemistry ◽  
Broad Scope ◽  
The Origin Of Life ◽  
Life On Earth

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.

scholarly journals Geochemistry and the Origin of Life: From Extraterrestrial Processes, Chemical Evolution on Earth, Fossilized Life’s Records, to Natures of the Extant Life

Life ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 39 ◽  
Author(s):  
Satoru Nakashima ◽  
Yoko Kebukawa ◽  
Norio Kitadai ◽  
Motoko Igisu ◽  
Natsuki Matsuoka
Keyword(s):  
Origin Of Life ◽  
Chemical Evolution ◽  
Building Blocks ◽  
Spectroscopic Studies ◽  
Research Progress ◽  
Complex Nature ◽  
Water Molecules ◽  
Evolution Of Life ◽  
The Origin Of Life ◽  
Emergence Of Life

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.

scholarly journals Self-assembly processes in the prebiotic environment

2006 ◽  
Vol 361 (1474) ◽  
pp. 1809-1818 ◽  
Author(s):  
David Deamer ◽  
Sara Singaram ◽  
Sudha Rajamani ◽  
Vladimir Kompanichenko ◽  
Stephen Guggenheim
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Self Assembly ◽  
Initial Study ◽  
Aqueous Environment ◽  
Organic Solutes ◽  
Mineral Surfaces ◽  
Molecular Systems ◽  
Intermediate Temperature Range ◽  
The Origin Of Life

An important question guiding research on the origin of life concerns the environmental conditions where molecular systems with the properties of life first appeared on the early Earth. An appropriate site would require liquid water, a source of organic compounds, a source of energy to drive polymerization reactions and a process by which the compounds were sufficiently concentrated to undergo physical and chemical interactions. One such site is a geothermal setting, in which organic compounds interact with mineral surfaces to promote self-assembly and polymerization reactions. Here, we report an initial study of two geothermal sites where mixtures of representative organic solutes (amino acids, nucleobases, a fatty acid and glycerol) and phosphate were mixed with high-temperature water in clay-lined pools. Most of the added organics and phosphate were removed from solution with half-times measured in minutes to a few hours. Analysis of the clay, primarily smectite and kaolin, showed that the organics were adsorbed to the mineral surfaces at the acidic pH of the pools, but could subsequently be released in basic solutions. These results help to constrain the range of possible environments for the origin of life. A site conducive to self-assembly of organic solutes would be an aqueous environment relatively low in ionic solutes, at an intermediate temperature range and neutral pH ranges, in which cyclic concentration of the solutes can occur by transient dry intervals.

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