1
|
Witkowski O, Schwitzgebel E. The Ethics of Life as It Could Be: Do We Have Moral Obligations to Artificial Life? ARTIFICIAL LIFE 2024; 30:193-215. [PMID: 38656414 DOI: 10.1162/artl_a_00436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The field of Artificial Life studies the nature of the living state by modeling and synthesizing living systems. Such systems, under certain conditions, may come to deserve moral consideration similar to that given to nonhuman vertebrates or even human beings. The fact that these systems are nonhuman and evolve in a potentially radically different substrate should not be seen as an insurmountable obstacle to their potentially having rights, if they are sufficiently sophisticated in other respects. Nor should the fact that they owe their existence to us be seen as reducing their status as targets of moral concern. On the contrary, creators of Artificial Life may have special obligations to their creations, resembling those of an owner to their pet or a parent to their child. For a field that aims to create artificial life-forms with increasing levels of sophistication, it is crucial to consider the possible ethical implications of our activities, with an eye toward assessing potential moral obligations for which we should be prepared. If Artificial Life is larger than life, then the ethics of artificial beings should be larger than human ethics.
Collapse
Affiliation(s)
- Olaf Witkowski
- Cross Compass Ltd. Cross Labs University of Tokyo College of Arts and Sciences.
| | | |
Collapse
|
2
|
Colón-Santos S, Vázquez-Salazar A, Adams A, Campillo-Balderas JA, Hernández-Morales R, Jácome R, Muñoz-Velasco I, Rodriguez LE, Schaible MJ, Schaible GA, Szeinbaum N, Thweatt JL, Trubl G. Chapter 2: What Is Life? ASTROBIOLOGY 2024; 24:S40-S56. [PMID: 38498820 DOI: 10.1089/ast.2021.0116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
The question "What is life?" has existed since the beginning of recorded history. However, the scientific and philosophical contexts of this question have changed and been refined as advancements in technology have revealed both fine details and broad connections in the network of life on Earth. Understanding the framework of the question "What is life?" is central to formulating other questions such as "Where else could life be?" and "How do we search for life elsewhere?" While many of these questions are addressed throughout the Astrobiology Primer 3.0, this chapter gives historical context for defining life, highlights conceptual characteristics shared by all life on Earth as well as key features used to describe it, discusses why it matters for astrobiology, and explores both challenges and opportunities for finding an informative operational definition.
Collapse
Affiliation(s)
- Stephanie Colón-Santos
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Wisconsin, USA
- Department of Botany, University of Wisconsin-Madison, Wisconsin, USA
| | - Alberto Vázquez-Salazar
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Department of Chemical and Biomolecular Engineering, University of California Los Angeles, California, USA
| | - Alyssa Adams
- Department of Botany, University of Wisconsin-Madison, Wisconsin, USA
| | | | - Ricardo Hernández-Morales
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Rodrigo Jácome
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Israel Muñoz-Velasco
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Laura E Rodriguez
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Lunar and Planetary Institute, Universities Space Research Association, Houston, Texas, USA
| | - Micah J Schaible
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - George A Schaible
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Nadia Szeinbaum
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Jennifer L Thweatt
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA. (Former)
| | - Gareth Trubl
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| |
Collapse
|
3
|
Brown OR, Hullender DA. Neo-Darwinism must Mutate to survive. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 172:24-38. [PMID: 35439500 DOI: 10.1016/j.pbiomolbio.2022.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/06/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
Darwinian evolution is a nineteenth century descriptive concept that itself has evolved. Selection by survival of the fittest was a captivating idea. Microevolution was biologically and empirically verified by discovery of mutations. There has been limited progress to the modern synthesis. The central focus of this perspective is to provide evidence to document that selection based on survival of the fittest is insufficient for other than microevolution. Realistic probability calculations based on probabilities associated with microevolution are presented. However, macroevolution (required for all speciation events and the complexifications appearing in the Cambrian explosion) are shown to be probabilistically highly implausible (on the order of 10-50) when based on selection by survival of the fittest. We conclude that macroevolution via survival of the fittest is not salvageable by arguments for random genetic drift and other proposed mechanisms. Evolutionary biology is relevant to cancer mechanisms with significance beyond academics. We challenge evolutionary biology to advance boldly beyond the inadequacies of the modern synthesis toward a unifying theory modeled after the Grand Unified Theory in physics. This should include the possibility of a fifth force in nature. Mathematics should be rigorously applied to current and future evolutionary empirical discoveries. We present justification that molecular biology and biochemistry must evolve to aeon (life) chemistry that acknowledges the uniqueness of enzymes for life. To evolve, biological evolution must face the known deficiencies, especially the limitations of the concept survival of the fittest, and seek solutions in Eigen's concept of self-organization, Schrödinger's negentropy, and novel approaches.
Collapse
Affiliation(s)
- Olen R Brown
- Dalton Cardiovascular Research Center, University of Missouri- Columbia, USA.
| | - David A Hullender
- Professor of Mechanical and Aerospace Engineering at the University of Texas at Arlington, USA
| |
Collapse
|
4
|
Sithamparam M, Satthiyasilan N, Chen C, Jia TZ, Chandru K. A material-based panspermia hypothesis: The potential of polymer gels and membraneless droplets. Biopolymers 2022; 113:e23486. [PMID: 35148427 DOI: 10.1002/bip.23486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 01/08/2023]
Abstract
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.
Collapse
Affiliation(s)
- Mahendran Sithamparam
- Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia (UKM), Bangi, Selangor, Malaysia
| | - Nirmell Satthiyasilan
- Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia (UKM), Bangi, Selangor, Malaysia
| | - Chen Chen
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Tony Z Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan.,Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Kuhan Chandru
- Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia (UKM), Bangi, Selangor, Malaysia
| |
Collapse
|
5
|
Chance and Necessity in the Evolution of Matter to Life: A Comprehensive Hypothesis. Symmetry (Basel) 2021. [DOI: 10.3390/sym13101918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Specialists in several branches of life sciences are trying to solve, piece by piece, the immensely complex puzzle of the origin of life. Some parts of the puzzle seem to appear with a rather high degree of clarity, while others remain totally obscure. We cannot be sure that life emerged only on our Earth, but we believe that the presence of large amounts of water in its liquid state is absolutely essential for the emergence and evolution of living matter. We can also assume that the latter exploits everywhere the same light elements, mainly C, H, O, N, S, and P, and somehow manipulates the same simple monomeric and polymeric organic compounds, such as alpha-amino acids, carbohydrates, nucleic bases, and surface-active carboxylic acids. The author contributes to the field by stating that all fundamental particles of our matter are “homochiral” and predominantly produce in an absolute asymmetric synthesis amino acids of L-configuration and carbohydrates of D-series. Another important point is that free atmospheric oxygen mainly stems from the photolysis of water molecules by cosmic irradiation and is not necessarily bound to living organisms on the planet.
Collapse
|
6
|
Cornish-Bowden A, Cárdenas ML. The essence of life revisited: how theories can shed light on it. Theory Biosci 2021; 141:105-123. [PMID: 33956294 PMCID: PMC8101340 DOI: 10.1007/s12064-021-00342-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 03/23/2021] [Indexed: 12/12/2022]
Abstract
Disagreement over whether life is inevitable when the conditions can support life remains unresolved, but calculations show that self-organization can arise naturally from purely random effects. Closure to efficient causation, or the need for all specific catalysts used by an organism to be produced internally, implies that a true model of an organism cannot exist, though this does not exclude the possibility that some characteristics can be simulated. Such simulations indicate that there is a limit to how small a self-organizing system can be: much smaller than a bacterial cell, but around the size of a typical virus particle. All current theories of life incorporate, at least implicitly, the idea of catalysis, but they largely ignore the need for metabolic regulation.
Collapse
|
7
|
Chandru K, Jia TZ, Mamajanov I, Bapat N, Cleaves HJ. Prebiotic oligomerization and self-assembly of structurally diverse xenobiological monomers. Sci Rep 2020; 10:17560. [PMID: 33067516 PMCID: PMC7567815 DOI: 10.1038/s41598-020-74223-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 09/22/2020] [Indexed: 02/07/2023] Open
Abstract
Prebiotic chemists often study how modern biopolymers, e.g., peptides and nucleic acids, could have originated in the primitive environment, though most contemporary biomonomers don't spontaneously oligomerize under mild conditions without activation or catalysis. However, life may not have originated using the same monomeric components that it does presently. There may be numerous non-biological (or "xenobiological") monomer types that were prebiotically abundant and capable of facile oligomerization and self-assembly. Many modern biopolymers degrade abiotically preferentially via processes which produce thermodynamically stable ring structures, e.g. diketopiperazines in the case of proteins and 2', 3'-cyclic nucleotide monophosphates in the case of RNA. This weakness is overcome in modern biological systems by kinetic control, but this need not have been the case for primitive systems. We explored here the oligomerization of a structurally diverse set of prebiotically plausible xenobiological monomers, which can hydrolytically interconvert between cyclic and acyclic forms, alone or in the presence of glycine under moderate temperature drying conditions. These monomers included various lactones, lactams and a thiolactone, which varied markedly in their stability, propensity to oligomerize and apparent modes of initiation, and the oligomeric products of some of these formed self-organized microscopic structures which may be relevant to protocell formation.
Collapse
Affiliation(s)
- Kuhan Chandru
- Space Science Center (ANGKASA), Institute of Climate Change, Level 3, Research Complex, National University of Malaysia, UKM, 43600, Bangi, Selangor, Malaysia.
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technicka 5, 16628, Prague 6-Dejvice, Czech Republic.
| | - Tony Z Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
- Blue Marble Space Institute for Science, 1001 4th Ave, Suite 3201, Seattle, WA, 98154, USA
| | - Irena Mamajanov
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Niraja Bapat
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
- Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra, 411 008, India
| | - H James Cleaves
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
- Blue Marble Space Institute for Science, 1001 4th Ave, Suite 3201, Seattle, WA, 98154, USA
- Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ, 08540, USA
| |
Collapse
|
8
|
Defining Lyfe in the Universe: From Three Privileged Functions to Four Pillars. Life (Basel) 2020; 10:life10040042. [PMID: 32316364 PMCID: PMC7235751 DOI: 10.3390/life10040042] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 01/08/2023] Open
Abstract
Motivated by the need to paint a more general picture of what life is—and could be—with respect to the rest of the phenomena of the universe, we propose a new vocabulary for astrobiological research. Lyfe is defined as any system that fulfills all four processes of the living state, namely: dissipation, autocatalysis, homeostasis, and learning. Life is defined as the instance of lyfe that we are familiar with on Earth, one that uses a specific organometallic molecular toolbox to record information about its environment and achieve dynamical order by dissipating certain planetary disequilibria. This new classification system allows the astrobiological community to more clearly define the questions that propel their research—e.g., whether they are developing a historical narrative to explain the origin of life (on Earth), or a universal narrative for the emergence of lyfe, or whether they are seeking signs of life specifically, or lyfe at large across the universe. While the concept of “life as we don’t know it” is not new, the four pillars of lyfe offer a novel perspective on the living state that is indifferent to the particular components that might produce it.
Collapse
|
9
|
Recent Results on Computational Molecular Modeling of The Origins of Life. FOUNDATIONS OF COMPUTING AND DECISION SCIENCES 2020. [DOI: 10.2478/fcds-2020-0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
In the last decade of research in the origins of life, there has been an increase in the interest on theoretical molecular modeling methods aimed to improve the accuracy and speed of the algorithms that solve the molecular mechanics and chemical reactions of the matter. Research on the scenarios of prebiotic chemistry has also advanced. The presented work attempts to discuss the latest computational techniques and trends implemented so far. Although it is difficult to cover the full extent of the current publications, we tried to orient the reader into the modern tendencies and challenges faced by those who are in the origins of life field.
Collapse
|
10
|
Evolution of Life on Earth: tRNA, Aminoacyl-tRNA Synthetases and the Genetic Code. Life (Basel) 2020; 10:life10030021. [PMID: 32131473 PMCID: PMC7151597 DOI: 10.3390/life10030021] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 02/13/2020] [Accepted: 02/27/2020] [Indexed: 02/07/2023] Open
Abstract
Life on Earth and the genetic code evolved around tRNA and the tRNA anticodon. We posit that the genetic code initially evolved to synthesize polyglycine as a cross-linking agent to stabilize protocells. We posit that the initial amino acids to enter the code occupied larger sectors of the code that were then invaded by incoming amino acids. Displacements of amino acids follow selection rules. The code sectored from a glycine code to a four amino acid code to an eight amino acid code to an ~16 amino acid code to the standard 20 amino acid code with stops. The proposed patterns of code sectoring are now most apparent from patterns of aminoacyl-tRNA synthetase evolution. The Elongation Factor-Tu GTPase anticodon-codon latch that checks the accuracy of translation appears to have evolved at about the eight amino acid to ~16 amino acid stage. Before evolution of the EF-Tu latch, we posit that both the 1st and 3rd anticodon positions were wobble positions. The genetic code evolved via tRNA charging errors and via enzymatic modifications of amino acids joined to tRNAs, followed by tRNA and aminoacyl-tRNA synthetase differentiation. Fidelity mechanisms froze the code by inhibiting further innovation.
Collapse
|
11
|
Preiner M, Asche S, Becker S, Betts HC, Boniface A, Camprubi E, Chandru K, Erastova V, Garg SG, Khawaja N, Kostyrka G, Machné R, Moggioli G, Muchowska KB, Neukirchen S, Peter B, Pichlhöfer E, Radványi Á, Rossetto D, Salditt A, Schmelling NM, Sousa FL, Tria FDK, Vörös D, Xavier JC. The Future of Origin of Life Research: Bridging Decades-Old Divisions. Life (Basel) 2020; 10:E20. [PMID: 32110893 PMCID: PMC7151616 DOI: 10.3390/life10030020] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 12/12/2022] Open
Abstract
Research on the origin of life is highly heterogeneous. After a peculiar historical development, it still includes strongly opposed views which potentially hinder progress. In the 1st Interdisciplinary Origin of Life Meeting, early-career researchers gathered to explore the commonalities between theories and approaches, critical divergence points, and expectations for the future. We find that even though classical approaches and theories-e.g. bottom-up and top-down, RNA world vs. metabolism-first-have been prevalent in origin of life research, they are ceasing to be mutually exclusive and they can and should feed integrating approaches. Here we focus on pressing questions and recent developments that bridge the classical disciplines and approaches, and highlight expectations for future endeavours in origin of life research.
Collapse
Affiliation(s)
- Martina Preiner
- Institute of Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.G.G.); (F.D.K.T.)
| | - Silke Asche
- School of Chemistry, University of Glasgow, Glasgow G128QQ, UK;
| | - Sidney Becker
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK;
| | - Holly C. Betts
- School of Earth Sciences, University of Bristol, Bristol BS8 1RL, UK;
| | - Adrien Boniface
- Environmental Microbial Genomics, Laboratoire Ampère, Ecole Centrale de Lyon, Université de Lyon, 69130 Ecully, France;
| | - Eloi Camprubi
- Origins Center, Department of Earth Sciences, Utrecht University, 3584 CB Utrecht, The Netherlands;
| | - Kuhan Chandru
- Space Science Center (ANGKASA), Institute of Climate Change, Level 3, Research Complex, National University of Malaysia, UKM Bangi 43600, Selangor, Malaysia;
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technicka 5, 16628 Prague 6–Dejvice, Czech Republic
| | - Valentina Erastova
- UK Centre for Astrobiology, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK;
| | - Sriram G. Garg
- Institute of Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.G.G.); (F.D.K.T.)
| | - Nozair Khawaja
- Institut für Geologische Wissenschaften, Freie Universität Berlin, 12249 Berlin, Germany;
| | | | - Rainer Machné
- Institute of Synthetic Microbiology, University of Düsseldorf, 40225 Düsseldorf, Germany; (R.M.); (N.M.S.)
- Quantitative and Theoretical Biology, University of Düsseldorf, 40225 Düsseldorf, Germany
| | - Giacomo Moggioli
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4DQ, UK;
| | - Kamila B. Muchowska
- Université de Strasbourg, CNRS, ISIS, 8 allée Gaspard Monge, 67000 Strasbourg, France;
| | - Sinje Neukirchen
- Archaea Biology and Ecogenomics Division, University of Vienna, 1090 Vienna, Austria; (S.N.); (E.P.); (F.L.S.)
| | - Benedikt Peter
- Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany;
| | - Edith Pichlhöfer
- Archaea Biology and Ecogenomics Division, University of Vienna, 1090 Vienna, Austria; (S.N.); (E.P.); (F.L.S.)
| | - Ádám Radványi
- Department of Plant Systematics, Ecology and Theoretical Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary (D.V.)
- Institute of Evolution, MTA Centre for Ecological Research, Klebelsberg Kuno u. 3., H-8237 Tihany, Hungary
| | - Daniele Rossetto
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy;
| | - Annalena Salditt
- Systems Biophysics, Physics Department, Ludwig-Maximilians-Universität München, 80799 Munich, Germany;
| | - Nicolas M. Schmelling
- Institute of Synthetic Microbiology, University of Düsseldorf, 40225 Düsseldorf, Germany; (R.M.); (N.M.S.)
- Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674 Cologne, Germany
| | - Filipa L. Sousa
- Archaea Biology and Ecogenomics Division, University of Vienna, 1090 Vienna, Austria; (S.N.); (E.P.); (F.L.S.)
| | - Fernando D. K. Tria
- Institute of Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.G.G.); (F.D.K.T.)
| | - Dániel Vörös
- Department of Plant Systematics, Ecology and Theoretical Biology, Eötvös Loránd University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary (D.V.)
- Institute of Evolution, MTA Centre for Ecological Research, Klebelsberg Kuno u. 3., H-8237 Tihany, Hungary
| | - Joana C. Xavier
- Institute of Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.G.G.); (F.D.K.T.)
| |
Collapse
|
12
|
Cornish-Bowden A, Cárdenas ML. Contrasting theories of life: Historical context, current theories. In search of an ideal theory. Biosystems 2020; 188:104063. [DOI: 10.1016/j.biosystems.2019.104063] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/10/2019] [Accepted: 10/10/2019] [Indexed: 12/18/2022]
|
13
|
Polyesters as a Model System for Building Primitive Biologies from Non-Biological Prebiotic Chemistry. Life (Basel) 2020; 10:life10010006. [PMID: 31963928 PMCID: PMC7175156 DOI: 10.3390/life10010006] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/22/2019] [Accepted: 01/10/2020] [Indexed: 12/14/2022] Open
Abstract
A variety of organic chemicals were likely available on prebiotic Earth. These derived from diverse processes including atmospheric and geochemical synthesis and extraterrestrial input, and were delivered to environments including oceans, lakes, and subaerial hot springs. Prebiotic chemistry generates both molecules used by modern organisms, such as proteinaceous amino acids, as well as many molecule types not used in biochemistry. As prebiotic chemical diversity was likely high, and the core of biochemistry uses a rather small set of common building blocks, the majority of prebiotically available organic compounds may not have been those used in modern biochemistry. Chemical evolution was unlikely to have been able to discriminate which molecules would eventually be used in biology, and instead, interactions among compounds were governed simply by abundance and chemical reactivity. Previous work has shown that likely prebiotically available α-hydroxy acids can combinatorially polymerize into polyesters that self-assemble to create new phases which are able to compartmentalize other molecule types. The unexpectedly rich complexity of hydroxy acid chemistry and the likely enormous structural diversity of prebiotic organic chemistry suggests chemical evolution could have been heavily influenced by molecules not used in contemporary biochemistry, and that there is a considerable amount of prebiotic chemistry which remains unexplored.
Collapse
|
14
|
Bartlett SJ, Beckett P. Probing complexity: thermodynamics and computational mechanics approaches to origins studies. Interface Focus 2019; 9:20190058. [PMID: 31641432 DOI: 10.1098/rsfs.2019.0058] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2019] [Indexed: 12/15/2022] Open
Abstract
This paper proposes new avenues for origins research that apply modern concepts from stochastic thermodynamics, information thermodynamics and complexity science. Most approaches to the emergence of life prioritize certain compounds, reaction pathways, environments or phenomena. What they all have in common is the objective of reaching a state that is recognizably alive, usually positing the need for an evolutionary process. As with life itself, this correlates with a growth in the complexity of the system over time. Complexity often takes the form of an intuition or a proxy for a phenomenon that defies complete understanding. However, recent progress in several theoretical fields allows the rigorous computation of complexity. We thus propose that measurement and control of the complexity and information content of origins-relevant systems can provide novel insights that are absent in other approaches. Since we have no guarantee that the earliest forms of life (or alien life) used the same materials and processes as extant life, an appeal to complexity and information processing provides a more objective and agnostic approach to the search for life's beginnings. This paper gives an accessible overview of the three relevant branches of modern thermodynamics. These frameworks are not commonly applied in origins studies, but are ideally suited to the analysis of such non-equilibrium systems. We present proposals for the application of these concepts in both theoretical and experimental origins settings.
Collapse
Affiliation(s)
- Stuart J Bartlett
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.,Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Patrick Beckett
- Department of Chemical Engineering, University of California Davis, Davis, CA, USA.,Department of Civil and Environmental Engineering, University of California Davis, Davis, CA, USA
| |
Collapse
|