1
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Rainwater JH. Self-Organization and Phase Transitions in Driven Cellular Automata. ARTIFICIAL LIFE 2024; 30:302-322. [PMID: 38781165 DOI: 10.1162/artl_a_00437] [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: 05/25/2024]
Abstract
The Game of Life (GoL) cellular automaton is modified to inject order during execution of the state transition algorithm by making selected stable structures permanently active while interacting with normal active sites to create novel structures. A survey of the modified automaton's phenomenology and an analysis of its dynamics are presented in the context of the physics of the self-organization of matter by viewing the GoL as an artificial chemistry. These new structures become seeds for additional phases of structure building, analogous to nature's gravitational and thermodynamic churning of the geosphere that created material structures in phases, beginning the transition from geochemistry to prebiotic chemistry and laying foundational substrates for life-enabling organizational processes in an emerging biosphere. Evidence of selective self-assembly during phase transitions is reported where several GoL still life structures, configured as permanently active seeds evolving with random collections of active sites, resulted in geometrically identical structures as the GoL reached an equilibrium state of static density.
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Affiliation(s)
- J Hank Rainwater
- Retired Electromagnetic Sciences, Engineering Experiment Station (now the Georgia Tech Research Institute).
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2
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Banfalvi G. The Origin of RNA and the Formose-Ribose-RNA Pathway. Int J Mol Sci 2024; 25:6727. [PMID: 38928433 PMCID: PMC11203418 DOI: 10.3390/ijms25126727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/03/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Prebiotic pre-Darwinian reactions continued throughout biochemical or Darwinian evolution. Early chemical processes could have occurred on Earth between 4.5 and 3.6 billion years ago when cellular life was about to come into being. Pre-Darwinian evolution assumes the development of hereditary elements but does not regard them as self-organizing processes. The presence of biochemical self-organization after the pre-Darwinian evolution did not justify distinguishing between different types of evolution. From the many possible solutions, evolution selected from among those stable reactions that led to catalytic networks, and under gradually changing external conditions produced a reproducible, yet constantly evolving and adaptable, living system. Major abiotic factors included sunlight, precipitation, air, minerals, soil and the Earth's atmosphere, hydrosphere and lithosphere. Abiotic sources of chemicals contributed to the formation of prebiotic RNA, the development of genetic RNA, the RNA World and the initial life forms on Earth and the transition of genRNA to the DNA Empire, and eventually to the multitude of life forms today. The transition from the RNA World to the DNA Empire generated new processes such as oxygenic photosynthesis and the hierarchical arrangement of processes involved in the transfer of genetic information. The objective of this work is to unite earlier work dealing with the formose, the origin and synthesis of ribose and RNA reactions that were published as a series of independent reactions. These reactions are now regarded as the first metabolic pathway.
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Affiliation(s)
- Gaspar Banfalvi
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, 4032 Debrecen, Hungary
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3
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Schaible MJ, Szeinbaum N, Bozdag GO, Chou L, Grefenstette N, Colón-Santos S, Rodriguez LE, Styczinski MJ, Thweatt JL, Todd ZR, Vázquez-Salazar A, Adams A, Araújo MN, Altair T, Borges S, Burton D, Campillo-Balderas JA, Cangi EM, Caro T, Catalano E, Chen K, Conlin PL, Cooper ZS, Fisher TM, Fos SM, Garcia A, Glaser DM, Harman CE, Hermis NY, Hooks M, Johnson-Finn K, Lehmer O, Hernández-Morales R, Hughson KHG, Jácome R, Jia TZ, Marlow JJ, McKaig J, Mierzejewski V, Muñoz-Velasco I, Nural C, Oliver GC, Penev PI, Raj CG, Roche TP, Sabuda MC, Schaible GA, Sevgen S, Sinhadc P, Steller LH, Stelmach K, Tarnas J, Tavares F, Trubl G, Vidaurri M, Vincent L, Weber JM, Weng MM, Wilpiszeki RL, Young A. Chapter 1: The Astrobiology Primer 3.0. ASTROBIOLOGY 2024; 24:S4-S39. [PMID: 38498816 DOI: 10.1089/ast.2021.0129] [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 Astrobiology Primer 3.0 (ABP3.0) is a concise introduction to the field of astrobiology for students and others who are new to the field of astrobiology. It provides an entry into the broader materials in this supplementary issue of Astrobiology and an overview of the investigations and driving hypotheses that make up this interdisciplinary field. The content of this chapter was adapted from the other 10 articles in this supplementary issue and thus represents the contribution of all the authors who worked on these introductory articles. The content of this chapter is not exhaustive and represents the topics that the authors found to be the most important and compelling in a dynamic and changing field.
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Affiliation(s)
- Micah J Schaible
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Nadia Szeinbaum
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - G Ozan Bozdag
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Luoth Chou
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Center for Space Sciences and Technology, University of Maryland, Baltimore, Maryland, USA
- Georgetown University, Washington DC, USA
| | - Natalie Grefenstette
- Santa Fe Institute, Santa Fe, New Mexico, USA
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Stephanie Colón-Santos
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Wisconsin, USA
- Department of Botany, University of Wisconsin-Madison, Wisconsin, USA
| | - Laura E Rodriguez
- Lunar and Planetary Institute, Universities Space Research Association, Houston, Texas, USA
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - M J Styczinski
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- University of Washington, Seattle, Washington, USA
| | - Jennifer L Thweatt
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania, USA
| | - Zoe R Todd
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, 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
- Center for Space Sciences and Technology, University of Maryland, Baltimore, Maryland, USA
| | - M N Araújo
- Biochemistry Department, University of São Paulo, São Carlos, Brazil
| | - Thiago Altair
- Institute of Chemistry of São Carlos, Universidade de São Paulo, São Carlos, Brazil
- Department of Chemistry, College of the Atlantic, Bar Harbor, Maine, USA
| | | | - Dana Burton
- Department of Anthropology, George Washington University, Washington DC, USA
| | | | - Eryn M Cangi
- Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, Colorado, USA
| | - Tristan Caro
- Department of Geological Sciences, University of Colorado Boulder, Boulder, Colorado, USA
| | - Enrico Catalano
- Sant'Anna School of Advanced Studies, The BioRobotics Institute, Pisa, Italy
| | - Kimberly Chen
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Peter L Conlin
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Z S Cooper
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
| | - Theresa M Fisher
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
| | - Santiago Mestre Fos
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Amanda Garcia
- Department of Bacteriology, University of Wisconsin-Madison, Wisconsin, USA
| | - D M Glaser
- Arizona State University, Tempe, Arizona, USA
| | - Chester E Harman
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ninos Y Hermis
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Department of Physics and Space Sciences, University of Granada, Granada, Spain
| | - M Hooks
- NASA Johnson Space Center, Houston, Texas, USA
| | - K Johnson-Finn
- Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan
- Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Owen Lehmer
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
| | - Ricardo Hernández-Morales
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Kynan H G Hughson
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Rodrigo Jácome
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Tony Z Jia
- Blue Marble Space Institute of Science, Seattle, Washington, USA
- Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan
| | - Jeffrey J Marlow
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Jordan McKaig
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Veronica Mierzejewski
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
| | - 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
| | - Ceren Nural
- Istanbul Technical University, Istanbul, Turkey
| | - Gina C Oliver
- Department of Geology, San Bernardino Valley College, San Bernardino, California, USA
| | - Petar I Penev
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Chinmayee Govinda Raj
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Tyler P Roche
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Mary C Sabuda
- Department of Earth and Environmental Sciences, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA
- Biotechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, USA
| | - George A Schaible
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Serhat Sevgen
- Blue Marble Space Institute of Science, Seattle, Washington, USA
- Institute of Marine Sciences, Middle East Technical University, Erdemli, Mersin, Turkey
| | - Pritvik Sinhadc
- BEYOND: Center For Fundamental Concepts in Science, Arizona State University, Arizona, USA
- Dubai College, Dubai, United Arab Emirates
| | - Luke H Steller
- Australian Centre for Astrobiology, and School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, Australia
| | - Kamil Stelmach
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - J Tarnas
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Frank Tavares
- Space Enabled Research Group, MIT Media Lab, Cambridge, Massachusetts, USA
| | - Gareth Trubl
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Monica Vidaurri
- Center for Space Sciences and Technology, University of Maryland, Baltimore, Maryland, USA
- Department of Physics and Astronomy, Howard University, Washington DC, USA
| | - Lena Vincent
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Wisconsin, USA
| | - Jessica M Weber
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | | | - Amber Young
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Northern Arizona University, Flagstaff, Arizona, USA
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4
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Grefenstette N, Chou L, Colón-Santos S, Fisher TM, Mierzejewski V, Nural C, Sinhadc P, Vidaurri M, Vincent L, Weng MM. Chapter 9: Life as We Don't Know It. ASTROBIOLOGY 2024; 24:S186-S201. [PMID: 38498819 DOI: 10.1089/ast.2021.0103] [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
While Earth contains the only known example of life in the universe, it is possible that life elsewhere is fundamentally different from what we are familiar with. There is an increased recognition in the astrobiology community that the search for life should steer away from terran-specific biosignatures to those that are more inclusive to all life-forms. To start exploring the space of possibilities that life could occupy, we can try to dissociate life from the chemistry that composes it on Earth by envisioning how different life elsewhere could be in composition, lifestyle, medium, and form, and by exploring how the general principles that govern living systems on Earth might be found in different forms and environments across the Solar System. Exotic life-forms could exist on Mars or Venus, or icy moons like Europa and Enceladus, or even as a shadow biosphere on Earth. New perspectives on agnostic biosignature detection have also begun to emerge, allowing for a broader and more inclusive approach to seeking exotic life with unknown chemistry that is distinct from life as we know it on Earth.
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Affiliation(s)
- Natalie Grefenstette
- Santa Fe Institute, Santa Fe, New Mexico, USA
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Luoth Chou
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Georgetown University, Washington, DC, USA
| | | | - Theresa M Fisher
- School of Earth and Space Exploration, Arizona State University, Arizona, USA
| | | | - Ceren Nural
- Istanbul Technical University, Istanbul, Turkey
| | - Pritvik Sinhadc
- BEYOND: Center For Fundamental Concepts in Science, Arizona State University, Arizona, USA
- Dubai College, Dubai, United Arab Emirates
| | - Monica Vidaurri
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Howard University, DC, USA
| | - Lena Vincent
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Wisconsin, USA
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5
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Vela-Gallego S, Lewandowski B, Möhler J, Puente A, Gil-Cantero D, Wennemers H, de la Escosura A. Modifying the Catalytic Activity of Lipopeptide Assemblies with Nucleobases. Chemistry 2024; 30:e202303395. [PMID: 37877614 DOI: 10.1002/chem.202303395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 10/26/2023]
Abstract
Biohybrid catalysts that operate in aqueous media are intriguing for systems chemistry. In this paper, we investigate whether control over the self-assembly of biohybrid catalysts can tune their properties. As a model, we use the catalytic activity of functional hybrid molecules consisting of a catalytic H-dPro-Pro-Glu tripeptide, derivatized with fatty acid and nucleobase moieties. This combination of simple biological components merged the catalytic properties of the peptide with the self-assembly of the lipid, and the structural ordering of the nucleobases. The biomolecule hybrids self-assemble in aqueous media into fibrillar assemblies and catalyze the reaction between butanal and nitrostyrene. The interactions between the nucleobases enhanced the order of the supramolecular structures and affected their catalytic activity and stereoselectivity. The results point to the significant control and ordering that nucleobases can provide in the self-assembly of biologically inspired supramolecular catalysts.
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Affiliation(s)
- Sonia Vela-Gallego
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus Cantoblanco, 28049, Madrid, Spain
| | - Bartosz Lewandowski
- Laboratory of Organic Chemistry, D-CHAB, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Jasper Möhler
- Laboratory of Organic Chemistry, D-CHAB, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Alonso Puente
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus Cantoblanco, 28049, Madrid, Spain
| | - David Gil-Cantero
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología / CSIC, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Helma Wennemers
- Laboratory of Organic Chemistry, D-CHAB, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Andrés de la Escosura
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus Cantoblanco, 28049, Madrid, Spain
- Institute for Advanced Research in Chemistry (IAdChem), Campus de Cantoblanco, 28049, Madrid, Spain
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6
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Smith HB, Mathis C. Life detection in a universe of false positives: Can the Fatal Flaws of Exoplanet Biosignatures be Overcome Absent a Theory of Life? Bioessays 2023; 45:e2300050. [PMID: 37821360 DOI: 10.1002/bies.202300050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 09/24/2023] [Accepted: 09/27/2023] [Indexed: 10/13/2023]
Abstract
Astrobiology aims to determine the distribution and diversity of life in the universe. But as the word "biosignature" suggests, what will be detected is not life itself, but an observation implicating living systems. Our limited access to other worlds suggests this observation is more likely to reflect out-of-equilibrium gasses than a writhing octopus. Yet, anything short of a writhing octopus will raise skepticism about what has been detected. Resolving that skepticism requires a theory to delineate processes due to life and those due to abiotic mechanisms. This poses an existential question for life detection: How do astrobiologists plan to detect life on exoplanets via features shared between non-living and living systems? We argue that you cannot without an underlying theory of life. We illustrate this by analyzing the hypothetical detection of an "Earth 2.0" exoplanet. Without a theory of life, we argue the community should focus on identifying unambiguous features of life via four areas: examining life on Earth, building life in the lab, probing the solar system, and searching for technosignatures. Ultimately, we ask, what exactly do astrobiologists hope to learn by searching for life?
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Affiliation(s)
- Harrison B Smith
- Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Cole Mathis
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
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7
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Foote S, Sinhadc P, Mathis C, Walker SI. False Positives and the Challenge of Testing the Alien Hypothesis. ASTROBIOLOGY 2023; 23:1189-1201. [PMID: 37962842 DOI: 10.1089/ast.2023.0005] [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: 11/15/2023]
Abstract
The origin of life and the detection of alien life have historically been treated as separate scientific research problems. However, they are not strictly independent. Here, we discuss the need for a better integration of the sciences of life detection and origins of life. Framing these dual problems within the formalism of Bayesian hypothesis testing, we demonstrate via simple examples how high confidence in life detection claims require either (1) a strong prior hypothesis about the existence of life in a particular alien environment, or conversely, (2) signatures of life that are not susceptible to false positives. As a case study, we discuss the role of priors and hypothesis testing in recent results reporting potential detection of life in the venusian atmosphere and in the icy plumes of Enceladus. While many current leading biosignature candidates are subject to false positives because they are not definitive of life, our analyses demonstrate why it is necessary to shift focus to candidate signatures that are definitive. This indicates a necessity to develop methods that lack substantial false positives, by using observables for life that rely on prior hypotheses with strong theoretical and empirical support in identifying defining features of life. Abstract theories developed in pursuit of understanding universal features of life are more likely to be definitive and to apply to life-as-we-don't-know-it. We discuss Molecular Assembly theory as an example of such an observable which is applicable to life detection within the solar system. In the absence of alien examples these are best validated in origin of life experiments, substantiating the need for better integration between origins of life and biosignature science research communities. This leads to a conclusion that extraordinary claims in astrobiology (e.g., definitive detection of alien life) require extraordinary explanations, whereas the evidence itself could be quite ordinary.
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Affiliation(s)
- Searra Foote
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
| | - Pritvik Sinhadc
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Dubai College, Dubai, UAE
| | - Cole Mathis
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
| | - Sara Imari Walker
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
- Blue Marble Space Institute for Science, Seattle, Washington, USA
- ASU-SFI Center for Biosocial Complex Systems, Arizona State University, Tempe, Arizona, USA
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8
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Vitas M, Dobovišek A. Is Darwinian selection a retrograde driving force of evolution? Biosystems 2023; 233:105031. [PMID: 37734699 DOI: 10.1016/j.biosystems.2023.105031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/11/2023] [Accepted: 09/11/2023] [Indexed: 09/23/2023]
Abstract
Modern science has still not provided a satisfactory empirical explanation for the increasing complexity of living organisms through evolutionary history. As no agreed-upon definitions of the complexity exist, the working definition of biological complexity has been formulated. There is no theoretical reason to expect evolutionary lineages to increase in complexity over time, and there is no empirical evidence that they do so. In our discussion we have assumed the hypothesis that at the origins of life, evolution had to first involve autocatalytic systems that only subsequently acquired the capacity of genetic heredity. We discuss the role of Darwinian selection in evolution and pose the hypothesis that Darwinian selection acts predominantly as a retrograde driving force of evolution. In this context we understand the term retrograde evolution as a degeneration of living systems from higher complexity towards living systems with lower complexity. With the proposed hypothesis we have closed the gap between Darwinism and Lamarckism early in the evolutionary process. By Lamarckism, the action of a special principle called complexification force is understood here rather than inheritance of acquired characteristics.
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Affiliation(s)
- Marko Vitas
- Laze pri Borovnici 38, 1353, Borovnica, Slovenia.
| | - Andrej Dobovišek
- University of Maribor, Faculty of Natural Sciences and Mathematics, Koroška Cesta 160, 2000, Maribor, Slovenia; University of Maribor, Faculty of Medicine, Taborska Ulica 6B, 2000, Maribor, Slovenia.
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9
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Nogal N, Sanz-Sánchez M, Vela-Gallego S, Ruiz-Mirazo K, de la Escosura A. The protometabolic nature of prebiotic chemistry. Chem Soc Rev 2023; 52:7359-7388. [PMID: 37855729 PMCID: PMC10614573 DOI: 10.1039/d3cs00594a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Indexed: 10/20/2023]
Abstract
The field of prebiotic chemistry has been dedicated over decades to finding abiotic routes towards the molecular components of life. There is nowadays a handful of prebiotically plausible scenarios that enable the laboratory synthesis of most amino acids, fatty acids, simple sugars, nucleotides and core metabolites of extant living organisms. The major bottleneck then seems to be the self-organization of those building blocks into systems that can self-sustain. The purpose of this tutorial review is having a close look, guided by experimental research, into the main synthetic pathways of prebiotic chemistry, suggesting how they could be wired through common intermediates and catalytic cycles, as well as how recursively changing conditions could help them engage in self-organized and dissipative networks/assemblies (i.e., systems that consume chemical or physical energy from their environment to maintain their internal organization in a dynamic steady state out of equilibrium). In the article we also pay attention to the implications of this view for the emergence of homochirality. The revealed connectivity between those prebiotic routes should constitute the basis for a robust research program towards the bottom-up implementation of protometabolic systems, taken as a central part of the origins-of-life problem. In addition, this approach should foster further exploration of control mechanisms to tame the combinatorial explosion that typically occurs in mixtures of various reactive precursors, thus regulating the functional integration of their respective chemistries into self-sustaining protocellular assemblies.
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Affiliation(s)
- Noemí Nogal
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus Cantoblanco, 28049, Madrid, Spain.
| | - Marcos Sanz-Sánchez
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus Cantoblanco, 28049, Madrid, Spain.
| | - Sonia Vela-Gallego
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus Cantoblanco, 28049, Madrid, Spain.
| | - Kepa Ruiz-Mirazo
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, Leioa, Spain
- Department of Philosophy, University of the Basque Country, Leioa, Spain
| | - Andrés de la Escosura
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus Cantoblanco, 28049, Madrid, Spain.
- Institute for Advanced Research in Chemistry (IAdChem), Campus de Cantoblanco, 28049, Madrid, Spain
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10
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Distinguishing Biotic vs. Abiotic Origins of ‘Bio’signatures: Clues from Messy Prebiotic Chemistry for Detection of Life in the Universe. Life (Basel) 2023; 13:life13030766. [PMID: 36983921 PMCID: PMC10058490 DOI: 10.3390/life13030766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/04/2023] [Accepted: 03/11/2023] [Indexed: 03/16/2023] Open
Abstract
It is not a stretch to say that the search for extraterrestrial life is possibly the biggest of the cosmic endeavors that humankind has embarked upon. With the continued discovery of several Earth-like exoplanets, the hope of detecting potential biosignatures is multiplying amongst researchers in the astrobiology community. However, to be able to discern these signatures as being truly of biological origin, we also need to consider their probable abiotic origin. The field of prebiotic chemistry, which is aimed at understanding enzyme-free chemical syntheses of biologically relevant molecules, could particularly aid in this regard. Specifically, certain peculiar characteristics of prebiotically pertinent messy chemical reactions, including diverse and racemic product yields and lower synthesis efficiencies, can be utilized in analyzing whether a perceived ‘signature of life’ could possibly have chemical origins. The knowledge gathered from understanding the transition from chemistry to biology during the origin of life could be used for creating a library of abiotically synthesized biologically relevant organic molecules. This can then be employed in designing, standardizing, and testing mission-specific instruments/analysis systems, while also enabling the effective targeting of exoplanets with potentially ‘ongoing’ molecular evolutionary processes for robust detection of life in future explorative endeavors.
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11
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Slootbeek AD, van Haren MHI, Smokers IBA, Spruijt E. Growth, replication and division enable evolution of coacervate protocells. Chem Commun (Camb) 2022; 58:11183-11200. [PMID: 36128910 PMCID: PMC9536485 DOI: 10.1039/d2cc03541c] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 09/13/2022] [Indexed: 11/21/2022]
Abstract
Living and proliferating cells undergo repeated cycles of growth, replication and division, all orchestrated by complex molecular networks. How a minimal cell cycle emerged and helped primitive cells to evolve remains one of the biggest mysteries in modern science, and is an active area of research in chemistry. Protocells are cell-like compartments that recapitulate features of living cells and may be seen as the chemical ancestors of modern life. While compartmentalization is not strictly required for primitive, open-ended evolution of self-replicating systems, it gives such systems a clear identity by setting the boundaries and it can help them overcome three major obstacles of dilution, parasitism and compatibility. Compartmentalization is therefore widely considered to be a central hallmark of primitive life, and various types of protocells are actively investigated, with the ultimate goal of developing a protocell capable of autonomous proliferation by mimicking the well-known cell cycle of growth, replication and division. We and others have found that coacervates are promising protocell candidates in which chemical building blocks required for life are naturally concentrated, and chemical reactions can be selectively enhanced or suppressed. This feature article provides an overview of how growth, replication and division can be realized with coacervates as protocells and what the bottlenecks are. Considerations are given for designing chemical networks in coacervates that can lead to sustained growth, selective replication and controlled division, in a way that they are linked together like in the cell cycle. Ultimately, such a system may undergo evolution by natural selection of certain phenotypes, leading to adaptation and the gain of new functions, and we end with a brief discussion of the opportunities for coacervates to facilitate this.
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Affiliation(s)
- Annemiek D Slootbeek
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
| | - Merlijn H I van Haren
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
| | - Iris B A Smokers
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
| | - Evan Spruijt
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
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12
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Vela-Gallego S, Pardo-Botero Z, Moya C, de la Escosura A. Collective adaptability in a replication network of minimal nucleobase sequences. Chem Sci 2022; 13:10715-10724. [PMID: 36320689 PMCID: PMC9491195 DOI: 10.1039/d2sc02419e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/05/2022] [Indexed: 12/05/2022] Open
Abstract
A major challenge for understanding the origins of life is to explore how replication networks can engage in an evolutionary process. Herein, we shed light on this problem by implementing a network constituted by two different types of extremely simple biological components: the amino acid cysteine and the canonical nucleobases adenine and thymine, connected through amide bonds to the cysteine amino group and oxidation of its thiol into three possible disulfides. Supramolecular and kinetic analyses revealed that both self- and mutual interactions between such dinucleobase compounds drive their assembly and replication pathways. Those pathways involving sequence complementarity led to enhanced replication rates, suggesting a potential bias for selection. The interplay of synergistic dynamics and competition between replicators was then simulated, under conditions that are not easily accessible with experiments, in an open reactor parametrized and constrained with the unprecedentedly complete experimental kinetic data obtained for our replicative network. Interestingly, the simulations show bistability, as a selective amplification of different species depending on the initial mixture composition. Overall, this network configuration can favor a collective adaptability to changes in the availability of feedstock molecules, with disulfide exchange reactions serving as 'wires' that connect the different individual auto- and cross-catalytic pathways.
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Affiliation(s)
- Sonia Vela-Gallego
- Department of Organic Chemistry, Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
| | | | - Cristian Moya
- Department of Organic Chemistry, Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
| | - Andrés de la Escosura
- Department of Organic Chemistry, Universidad Autónoma de Madrid Campus de Cantoblanco 28049 Madrid Spain
- Institute for Advanced Research in Chemistry (IAdChem) Cantoblanco 28049 Madrid Spain
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13
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Malaterre C, Jeancolas C, Nghe P. The Origin of Life: What Is the Question? ASTROBIOLOGY 2022; 22:851-862. [PMID: 35594335 PMCID: PMC9298494 DOI: 10.1089/ast.2021.0162] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 03/12/2022] [Indexed: 06/15/2023]
Abstract
The question of the origin of life is a tenacious question that challenges many branches of science but is also extremely multifaceted. While prebiotic chemistry and micropaleontology reformulate the question as that of explaining the appearance of life on Earth in the deep past, systems chemistry and synthetic biology typically understand the question as that of demonstrating the synthesis of novel living matter from nonliving matter independently of historical constraints. The objective of this contribution is to disentangle the different readings of the origin-of-life question found in science. We identify three main dimensions along which the question can be differently constrained depending on context: historical adequacy, natural spontaneity, and similarity to life-as-we-know-it. We argue that the epistemic status of what needs to be explained-the explanandum-varies from approximately true when the origin-of-life question is the most constrained to entirely speculative when the constraints are the most relaxed. This difference in epistemic status triggers a shift in the nature of the origin-of-life question from an explanation-seeking question in the most constrained case to a fact-establishing question in the lesser-constrained ones. We furthermore explore how answers to some interpretations of the origin-of-life questions matter for other interpretations.
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Affiliation(s)
- Christophe Malaterre
- Département de philosophie, Université du Québec à Montréal (UQAM), Montréal, Canada
- Centre interuniversitaire de recherche sur la science et la technologie (CIRST), Université du Québec à Montréal (UQAM), Montréal, Canada
| | - Cyrille Jeancolas
- Laboratoire Biophysique et Évolution, UMR Chimie Biologie Innovation 8231, ESPCI Paris, Université PSL, CNRS, Paris, France
- Laboratoire d'Anthropologie Sociale, Collège de France, Paris, France
| | - Philippe Nghe
- Laboratoire Biophysique et Évolution, UMR Chimie Biologie Innovation 8231, ESPCI Paris, Université PSL, CNRS, Paris, France
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14
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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.
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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
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15
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Abstract
Although the knowledge about biological systems has advanced exponentially in recent decades, it is surprising to realize that the very definition of Life keeps presenting theoretical challenges. Even if several lines of reasoning seek to identify the essence of life phenomenon, most of these thoughts contain fundamental problem in their basic conceptual structure. Most concepts fail to identify either necessary or sufficient features to define life. Here, we analyzed the main conceptual frameworks regarding theoretical aspects that have been supporting the most accepted concepts of life, such as (i) the physical, (ii) the cellular and (iii) the molecular approaches. Based on an ontological analysis, we propose that Life should not be positioned under the ontological category of Matter. Yet, life should be better understood under the top-level ontology of "Process". Exercising an epistemological approach, we propose that the essential characteristic that pervades each and every living being is the presence of organic codes. Therefore, we explore theories in biosemiotics and code biology in order to propose a clear concept of life as a macrocode composed by multiple inter-related coding layers. This way, as life is a sort of metaphysical process of encoding, the living beings became the molecular materialization of that process. From the proposed concept, we show that the evolutionary process is a fundamental characteristic for life's maintenance but it is not necessary to define life, as many organisms are clearly alive but they do not participate in the evolutionary process (such as infertile hybrids). The current proposition opens a fertile field of debate in astrobiology, epistemology, biosemiotics, code biology and robotics.
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16
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Sharma S, Arya A, Cruz R, Cleaves II HJ. Automated Exploration of Prebiotic Chemical Reaction Space: Progress and Perspectives. Life (Basel) 2021; 11:1140. [PMID: 34833016 PMCID: PMC8624352 DOI: 10.3390/life11111140] [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: 09/07/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022] Open
Abstract
Prebiotic chemistry often involves the study of complex systems of chemical reactions that form large networks with a large number of diverse species. Such complex systems may have given rise to emergent phenomena that ultimately led to the origin of life on Earth. The environmental conditions and processes involved in this emergence may not be fully recapitulable, making it difficult for experimentalists to study prebiotic systems in laboratory simulations. Computational chemistry offers efficient ways to study such chemical systems and identify the ones most likely to display complex properties associated with life. Here, we review tools and techniques for modelling prebiotic chemical reaction networks and outline possible ways to identify self-replicating features that are central to many origin-of-life models.
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Affiliation(s)
- Siddhant Sharma
- Blue Marble Space Institute of Science, Seattle, WA 98154, USA; (S.S.); (A.A.); (R.C.)
- Department of Biochemistry, Deshbandhu College, University of Delhi, New Delhi 110019, India
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Aayush Arya
- Blue Marble Space Institute of Science, Seattle, WA 98154, USA; (S.S.); (A.A.); (R.C.)
- Department of Physics, Lovely Professional University, Jalandhar-Delhi GT Road, Phagwara 144001, India
| | - Romulo Cruz
- Blue Marble Space Institute of Science, Seattle, WA 98154, USA; (S.S.); (A.A.); (R.C.)
- Big Data Laboratory, Information and Communications Technology Center (CTIC), National University of Engineering, Amaru 210, Lima 15333, Peru
| | - Henderson James Cleaves II
- Blue Marble Space Institute of Science, Seattle, WA 98154, USA; (S.S.); (A.A.); (R.C.)
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan
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17
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Abbas M, Lipiński WP, Nakashima KK, Huck WTS, Spruijt E. A short peptide synthon for liquid-liquid phase separation. Nat Chem 2021; 13:1046-1054. [PMID: 34645986 DOI: 10.1038/s41557-021-00788-x] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 08/13/2021] [Indexed: 11/09/2022]
Abstract
Liquid-liquid phase separation of disordered proteins has emerged as a ubiquitous route to membraneless compartments in living cells, and similar coacervates may have played a role when the first cells formed. However, existing coacervates are typically made of multiple macromolecular components, and designing short peptide analogues capable of self-coacervation has proven difficult. Here we present a short peptide synthon for phase separation, made of only two dipeptide stickers linked via a flexible, hydrophilic spacer. These small-molecule compounds self-coacervate into micrometre-sized liquid droplets at sub-millimolar concentrations, which retain up to 75 wt% water. The design is general and we derive guidelines for the required sticker hydrophobicity and spacer polarity. To illustrate their potential as protocells, we create a disulfide-linked derivative that undergoes reversible compartmentalization controlled by redox chemistry. The resulting coacervates sequester and melt nucleic acids, and act as microreactors that catalyse two different anabolic reactions yielding molecules of increasing complexity. This provides a stepping stone for new coacervate-based protocells made of single peptide species.
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Affiliation(s)
- Manzar Abbas
- Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Wojciech P Lipiński
- Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Karina K Nakashima
- Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Wilhelm T S Huck
- Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Evan Spruijt
- Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands.
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18
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Wang W, Qiao L, He J, Ju Y, Yu K, Kan G, Guo C, Zhang H, Jiang J. Water Microdroplets Allow Spontaneously Abiotic Production of Peptides. J Phys Chem Lett 2021; 12:5774-5780. [PMID: 34134488 DOI: 10.1021/acs.jpclett.1c01083] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The chemistry of abiotic synthesis of peptides in the context of their prebiotic origins is a continuing challenge that arises from thermodynamic and kinetic constraints in aqueous media. Here we reported a strategy of microdroplets' mass spectrometry for peptide bonds formed from pure amino acids or a mixture in the presence of phosphoric acids in aqueous microdroplets. In contrast to bulk experiments, the condensation reactions proceed spontaneously under ambient conditions. The microdroplet gave a negative free-energy change (ΔG ∼ -1.1 kcal/mol), and product yields of ∼75% were obtained at the scale of a few milliseconds. Experiments in which nebulization gas pressure and external charge were varied established dependence of peptide production on the droplet size that has a high surface-to-volume ratio. It is concluded that the condensation reactions occurred at or near the air-water interfaces of microdroplets. This aqueous microdroplets approach also provides a route for chemistry synthesis in the prebiotic era.
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Affiliation(s)
- Wenxin Wang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Lina Qiao
- Marine College, Shandong University (Weihai), Weihai, Shandong 264209, China
| | - Jing He
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Yun Ju
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Kai Yu
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Guangfeng Kan
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
| | - Changlu Guo
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
| | - Hong Zhang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Jie Jiang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
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19
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Marshall SM, Mathis C, Carrick E, Keenan G, Cooper GJT, Graham H, Craven M, Gromski PS, Moore DG, Walker SI, Cronin L. Identifying molecules as biosignatures with assembly theory and mass spectrometry. Nat Commun 2021; 12:3033. [PMID: 34031398 PMCID: PMC8144626 DOI: 10.1038/s41467-021-23258-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/07/2021] [Indexed: 01/14/2023] Open
Abstract
The search for alien life is hard because we do not know what signatures are unique to life. We show why complex molecules found in high abundance are universal biosignatures and demonstrate the first intrinsic experimentally tractable measure of molecular complexity, called the molecular assembly index (MA). To do this we calculate the complexity of several million molecules and validate that their complexity can be experimentally determined by mass spectrometry. This approach allows us to identify molecular biosignatures from a set of diverse samples from around the world, outer space, and the laboratory, demonstrating it is possible to build a life detection experiment based on MA that could be deployed to extraterrestrial locations, and used as a complexity scale to quantify constraints needed to direct prebiotically plausible processes in the laboratory. Such an approach is vital for finding life elsewhere in the universe or creating de-novo life in the lab.
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Affiliation(s)
| | - Cole Mathis
- School of Chemistry, University of Glasgow, Glasgow, UK
| | - Emma Carrick
- School of Chemistry, University of Glasgow, Glasgow, UK
| | - Graham Keenan
- School of Chemistry, University of Glasgow, Glasgow, UK
| | | | - Heather Graham
- Astrobiology Analytical Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | | | - Douglas G Moore
- Beyond Centre for Concepts in Fundamental Science, Arizona State University, Tempe, AZ, USA
| | - Sara I Walker
- Beyond Centre for Concepts in Fundamental Science, Arizona State University, Tempe, AZ, USA
| | - Leroy Cronin
- School of Chemistry, University of Glasgow, Glasgow, UK.
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20
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Marshall P. Biology transcends the limits of computation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 165:88-101. [PMID: 33961842 DOI: 10.1016/j.pbiomolbio.2021.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 11/29/2022]
Abstract
Cognition-sensing and responding to the environment-is the unifying principle behind the genetic code, origin of life, evolution, consciousness, artificial intelligence, and cancer. However, the conventional model of biology seems to mistake cause and effect. According to the reductionist view, the causal chain in biology is chemicals → code → cognition. Despite this prevailing view, there are no examples in the literature to show that the laws of physics and chemistry can produce codes, or that codes produce cognition. Chemicals are just the physical layer of any information system. In contrast, although examples of cognition generating codes and codes controlling chemicals are ubiquitous in biology and technology, cognition remains a mystery. Thus, the central question in biology is: What is the nature and origin of cognition? In order to elucidate this pivotal question, we must cultivate a deeper understanding of information flows. Through this lens, we see that biological cognition is volitional (i.e., deliberate, intentional, or knowing), and while technology is constrained by deductive logic, living things make choices and generate novel information using inductive logic. Information has been called "the hard problem of life' and cannot be fully explained by known physical principles (Walker et al., 2017). The present paper uses information theory (the mathematical foundation of our digital age) and Turing machines (computers) to highlight inaccuracies in prevailing reductionist models of biology, and proposes that the correct causation sequence is cognition → code → chemicals.
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Affiliation(s)
- Perry Marshall
- Evolution 2.0, 805 Lake Street #295 Oak Park, IL, 60301, USA.
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21
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Guan P, Xie C, Li L, Fang X, Wu F, Hu JJ, Tang K. Structural resolution of disaccharides through halogen anion complexation using negative trapped ion mobility spectrometry. Talanta 2021; 230:122348. [PMID: 33934797 DOI: 10.1016/j.talanta.2021.122348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/28/2021] [Accepted: 03/18/2021] [Indexed: 01/14/2023]
Abstract
Carbohydrates are an indispensable part of early life evolution. The determination of their structures is a key step to analyze their critical roles in biological systems. A variation of composition, glycosidic linkage, and (or) configuration between carbohydrate isomers induces structure diversity and brings challenges for their structural determination. Ion mobility spectrometry (IMS), an emerging gas-phase ion separation technology, has been considered as a promising tool for performing carbohydrate structure elucidation. In this work, eight disaccharides were analyzed by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS) in the negative ion mode as the complexed form of [M + X]-, where M = disaccharide, and X = Cl, Br, and I. As compared to the positive ion analysis of the selected disaccharide in a sodiated form, a reversal charge state provided the ability to eliminate or even reverse the collision cross section (CCS) difference between disaccharide isomers. By the combination of TIMS analysis and the calculation of density functional theory, the only observed two conformers of ions [lactulose + I]- may result from different adduction sites for an iodide anion. Based on the comparison of different halogen adducts, the [M + I]- ion form exhibited more powerful ability for isomeric disaccharide differentiation with an average resolution (RP-P) of 1.17, which results in a 34.5% improvement as compared to the corresponding chloride adducts. This result indicates that the use of negative charge states, especially the complexation of an iodide anion, could be a supplemental strategy to commonly used positive ion analysis for carbohydrate separation.
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Affiliation(s)
- Pengfei Guan
- Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, Ningbo University, Ningbo, 315211, PR China; School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China
| | - Chengyi Xie
- Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, Ningbo University, Ningbo, 315211, PR China; Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo, 315211, PR China
| | - Lei Li
- Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, Ningbo University, Ningbo, 315211, PR China; School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China
| | - Xiangyu Fang
- Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, Ningbo University, Ningbo, 315211, PR China; School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China
| | - Fangling Wu
- Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, Ningbo University, Ningbo, 315211, PR China; School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China
| | - Jun Jack Hu
- Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, Ningbo University, Ningbo, 315211, PR China; School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
| | - Keqi Tang
- Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, Ningbo University, Ningbo, 315211, PR China; School of Material Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
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22
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Smith HB, Kim H, Walker SI. Scarcity of scale-free topology is universal across biochemical networks. Sci Rep 2021; 11:6542. [PMID: 33753807 PMCID: PMC7985396 DOI: 10.1038/s41598-021-85903-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/19/2021] [Indexed: 01/31/2023] Open
Abstract
Biochemical reactions underlie the functioning of all life. Like many examples of biology or technology, the complex set of interactions among molecules within cells and ecosystems poses a challenge for quantification within simple mathematical objects. A large body of research has indicated many real-world biological and technological systems, including biochemistry, can be described by power-law relationships between the numbers of nodes and edges, often described as "scale-free". Recently, new statistical analyses have revealed true scale-free networks are rare. We provide a first application of these methods to data sampled from across two distinct levels of biological organization: individuals and ecosystems. We analyze a large ensemble of biochemical networks including networks generated from data of 785 metagenomes and 1082 genomes (sampled from the three domains of life). The results confirm no more than a few biochemical networks are any more than super-weakly scale-free. Additionally, we test the distinguishability of individual and ecosystem-level biochemical networks and show there is no sharp transition in the structure of biochemical networks across these levels of organization moving from individuals to ecosystems. This result holds across different network projections. Our results indicate that while biochemical networks are not scale-free, they nonetheless exhibit common structure across different levels of organization, independent of the projection chosen, suggestive of shared organizing principles across all biochemical networks.
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Affiliation(s)
- Harrison B. Smith
- grid.215654.10000 0001 2151 2636School of Earth and Space Exploration, Arizona State University, Tempe, AZ USA ,grid.32197.3e0000 0001 2179 2105Present Address: Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo Japan
| | - Hyunju Kim
- grid.215654.10000 0001 2151 2636School of Earth and Space Exploration, Arizona State University, Tempe, AZ USA ,grid.215654.10000 0001 2151 2636Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ USA ,grid.215654.10000 0001 2151 2636ASU-SFI Center for Biosocial Complex Systems, Arizona State University, Tempe, AZ USA
| | - Sara I. Walker
- grid.215654.10000 0001 2151 2636School of Earth and Space Exploration, Arizona State University, Tempe, AZ USA ,grid.215654.10000 0001 2151 2636Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ USA ,grid.215654.10000 0001 2151 2636ASU-SFI Center for Biosocial Complex Systems, Arizona State University, Tempe, AZ USA ,grid.209665.e0000 0001 1941 1940Santa Fe Institute, Santa Fe, NM USA
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23
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Kim H, Valentini G, Hanson J, Walker SI. Informational architecture across non-living and living collectives. Theory Biosci 2021; 140:325-341. [PMID: 33532895 PMCID: PMC8629804 DOI: 10.1007/s12064-020-00331-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/12/2020] [Indexed: 11/24/2022]
Abstract
Collective behavior is widely regarded as a hallmark property of living and intelligent systems. Yet, many examples are known of simple physical systems that are not alive, which nonetheless display collective behavior too, prompting simple physical models to often be adopted to explain living collective behaviors. To understand collective behavior as it occurs in living examples, it is important to determine whether or not there exist fundamental differences in how non-living and living systems act collectively, as well as the limits of the intuition that can be built from simpler, physical examples in explaining biological phenomenon. Here, we propose a framework for comparing non-living and living collectives as a continuum based on their information architecture: that is, how information is stored and processed across different degrees of freedom. We review diverse examples of collective phenomena, characterized from an information-theoretic perspective, and offer views on future directions for quantifying living collective behaviors based on their informational structure.
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Affiliation(s)
- Hyunju Kim
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
- ASU-SFI Center for Biosocial Complex Systems, Arizona State University and Santa Fe Institute, Tempe, USA
| | - Gabriele Valentini
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Jake Hanson
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Sara Imari Walker
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA.
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA.
- ASU-SFI Center for Biosocial Complex Systems, Arizona State University and Santa Fe Institute, Tempe, USA.
- Santa Fe Institute, Santa Fe, NM, USA.
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24
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Pohorille A, Sokolowska J. Evaluating Biosignatures for Life Detection. ASTROBIOLOGY 2020; 20:1236-1250. [PMID: 32808814 PMCID: PMC7591378 DOI: 10.1089/ast.2019.2151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Conceptual frameworks are developed for evaluating the ability of different biosignatures to provide evidence for the presence of life in planned missions or observational studies. The focus is on intrinsic characteristics of biosignatures in space environments rather than on their detection, which depends on technology. Evaluation procedures are drawn from extensive studies in decision theory on related problems in business, engineering, medical fields, and the social arena. Three approaches are particularly useful. Two of them, Signal Detection Theory and Bayesian hypothesis testing, are based on probabilities. The third approach is based on utility theory. In all the frameworks, knowledge about a subject matter has to be translated into probabilities and/or utilities in a multistep process called elicitation. We present the first attempt to cover all steps, from acquiring knowledge about biosignatures to assigning probabilities or utilities to global quantities, such as false positives and false negatives. Since elicitation involves human judgment that is always prone to perceptual and cognitive biases, the relevant biases are discussed and illustrated in examples. We further discuss at which stage of elicitation human judgment should be involved to ensure the most reliable outcomes. An example, how evaluating biosignatures might be implemented, is given in the Supplementary Information.
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Affiliation(s)
- Andrew Pohorille
- Exobiology Branch, NASA Ames Research Center, Moffett Field, California, USA
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25
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The Fuzziness in Molecular, Supramolecular, and Systems Chemistry. MOLECULES (BASEL, SWITZERLAND) 2020; 25:molecules25163634. [PMID: 32785069 PMCID: PMC7463983 DOI: 10.3390/molecules25163634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/31/2022]
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26
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Frenkel-Pinter M, Samanta M, Ashkenasy G, Leman LJ. Prebiotic Peptides: Molecular Hubs in the Origin of Life. Chem Rev 2020; 120:4707-4765. [PMID: 32101414 DOI: 10.1021/acs.chemrev.9b00664] [Citation(s) in RCA: 148] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The fundamental roles that peptides and proteins play in today's biology makes it almost indisputable that peptides were key players in the origin of life. Insofar as it is appropriate to extrapolate back from extant biology to the prebiotic world, one must acknowledge the critical importance that interconnected molecular networks, likely with peptides as key components, would have played in life's origin. In this review, we summarize chemical processes involving peptides that could have contributed to early chemical evolution, with an emphasis on molecular interactions between peptides and other classes of organic molecules. We first summarize mechanisms by which amino acids and similar building blocks could have been produced and elaborated into proto-peptides. Next, non-covalent interactions of peptides with other peptides as well as with nucleic acids, lipids, carbohydrates, metal ions, and aromatic molecules are discussed in relation to the possible roles of such interactions in chemical evolution of structure and function. Finally, we describe research involving structural alternatives to peptides and covalent adducts between amino acids/peptides and other classes of molecules. We propose that ample future breakthroughs in origin-of-life chemistry will stem from investigations of interconnected chemical systems in which synergistic interactions between different classes of molecules emerge.
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Affiliation(s)
- Moran Frenkel-Pinter
- NSF/NASA Center for Chemical Evolution, https://centerforchemicalevolution.com/.,School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Mousumi Samanta
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Gonen Ashkenasy
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Luke J Leman
- NSF/NASA Center for Chemical Evolution, https://centerforchemicalevolution.com/.,Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
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27
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Aldana M, Fuentes-Cabrera M, Zumaya M. Self-Propulsion Enhances Polymerization. ENTROPY 2020; 22:e22020251. [PMID: 33286025 PMCID: PMC7516688 DOI: 10.3390/e22020251] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 11/28/2022]
Abstract
Self-assembly is a spontaneous process through which macroscopic structures are formed from basic microscopic constituents (e.g., molecules or colloids). By contrast, the formation of large biological molecules inside the cell (such as proteins or nucleic acids) is a process more akin to self-organization than to self-assembly, as it requires a constant supply of external energy. Recent studies have tried to merge self-assembly with self-organization by analyzing the assembly of self-propelled (or active) colloid-like particles whose motion is driven by a permanent source of energy. Here we present evidence that points to the fact that self-propulsion considerably enhances the assembly of polymers: self-propelled molecules are found to assemble faster into polymer-like structures than non self-propelled ones. The average polymer length increases towards a maximum as the self-propulsion force increases. Beyond this maximum, the average polymer length decreases due to the competition between bonding energy and disruptive forces that result from collisions. The assembly of active molecules might have promoted the formation of large pre-biotic polymers that could be the precursors of the informational polymers we observe nowadays.
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Affiliation(s)
- Maximino Aldana
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Colonia Chamilpa, Cuernavaca 62210, Morelos, Mexico;
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico City, Mexico
- Correspondence: ; Tel.: +52-777-329-1787
| | - Miguel Fuentes-Cabrera
- Oak Ridge National Laboratory, Center for Nanophase Materials Sciences, Oak Ridge, TN 37831, USA;
- Oak Ridge National Laboratory, Computational Sciences and Engineering Division, Oak Ridge, TN 37831, USA
| | - Martín Zumaya
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Colonia Chamilpa, Cuernavaca 62210, Morelos, Mexico;
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico City, Mexico
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28
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Morales-Reina S, Giri C, Leclercq M, Vela-Gallego S, de la Torre I, Castón JR, Surin M, de la Escosura A. Programmed Recognition between Complementary Dinucleolipids To Control the Self-Assembly of Lipidic Amphiphiles. Chemistry 2020; 26:1082-1090. [PMID: 31729787 DOI: 10.1002/chem.201904217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/25/2019] [Indexed: 01/01/2023]
Abstract
One of the major goals in systems chemistry is to create molecular assemblies with emergent properties that are characteristic of life. An interesting approach toward this goal is based on merging different biological building blocks into synthetic systems with properties arising from the combination of their molecular components. The covalent linkage of nucleic acids (or their constituents: nucleotides, nucleosides and nucleobases) with lipids in the same hybrid molecule leads, for example, to the so-called nucleolipids. Herein, we describe nucleolipids with a very short sequence of two nucleobases per lipid, which, in combination with hydrophobic effects promoted by the lipophilic chain, allow control of the self-assembly of lipidic amphiphiles to be achieved. The present work describes a spectroscopic and microscopy study of the structural features and dynamic self-assembly of dinucleolipids that contain adenine or thymine moieties, either pure or in mixtures. This approach leads to different self-assembled nanostructures, which include spherical, rectangular and fibrillar assemblies, as a function of the sequence of nucleobases and chiral effects of the nucleolipids involved. We also show evidence that the resulting architectures can encapsulate hydrophobic molecules, revealing their potential as drug delivery vehicles or as compartments to host interesting chemistries in their interior.
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Affiliation(s)
- Sara Morales-Reina
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Chandan Giri
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Maxime Leclercq
- Laboratory for Chemistry of Novel Materials, Center for Innovation in Materials and Polymers, University of Mons-UMONS, 20 Place du Parc, 7000, Mons, Belgium
| | - Sonia Vela-Gallego
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Isabel de la Torre
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - José R Castón
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología/CSIC, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Mathieu Surin
- Laboratory for Chemistry of Novel Materials, Center for Innovation in Materials and Polymers, University of Mons-UMONS, 20 Place du Parc, 7000, Mons, Belgium
| | - Andrés de la Escosura
- Department of Organic Chemistry, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain.,Institute for Advanced Research in Chemistry (IAdChem), Campus de Cantoblanco, 28049, Madrid, Spain
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29
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Abstract
The chemical or prebiotic evolution referred also to as pre-Darwinian evolution describes chemical reactions up to the origin of a self-replicating system that was capable of Darwinian evolution. These chemical processes took place on Earth between about 3.7 and 4.5 billion years ago when cellular life came into being. The pre-Darwinian chemical evolution usually assumes hereditary elements, but does not regard them as self-organizing processes. Physical and chemical self-organization led to uninterrupted pre-Darwinian and Darwinian evolution. Thus, it is not justified to distinguish between different types of evolution. From the many possible solutions, evolution selected among those reactions that generated catalytic networks incorporating chemical sequence information and under gradually changing circumstances produced a reproducible and stable living system that adapted to these conditions. Major issues in this review involve prebiotic reactions leading to genetic evolution involving (1) abiotic sources of components of ribonucleotides and xenobiotic nucleotides, (2) formation of prebiotic RNA, (3) development of genetic RNA from random-sequence noncoding RNA, (4) transition from RNA World to DNA Empire, (5) the role of oxygenic photosynthesis in genetic transitions, and (6) hierarchical arrangement of processes involved in the optimized genetic system.
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Affiliation(s)
- Gaspar Banfalvi
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary
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30
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Affiliation(s)
- Nathaniel Wagner
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Gonen Ashkenasy
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva, Israel.
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31
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Colón‐Santos S, Cooper GJT, Cronin L. Taming the Combinatorial Explosion of the Formose Reaction via Recursion within Mineral Environments. CHEMSYSTEMSCHEM 2019. [DOI: 10.1002/syst.201900014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
| | | | - Leroy Cronin
- School of ChemistryUniversity of Glasgow University Avenue Glasgow G12 8QQ UK
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32
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Vitas M, Dobovišek A. Towards a General Definition of Life. ORIGINS LIFE EVOL B 2019; 49:77-88. [PMID: 31222432 DOI: 10.1007/s11084-019-09578-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 06/04/2019] [Indexed: 01/18/2023]
Abstract
A new definition of life is proposed and discussed in the present article. It is formulated by modifying and extending NASA's working definition of life, which postulates that life is a "self-sustaining chemical system capable of Darwinian evolution". The new definition includes a thermodynamical aspect of life as a far from equilibrium system and considers the flow of information from the environment to the living system. In our derivation of the definition of life we have assumed the hypothesis, that during the emergence of life evolution had to first involve autocatalytic systems that only subsequently acquired the capacity of genetic heredity. The new proposed definition of life is independent of the mode of evolution, regardless of whether Lamarckian or Darwinian evolution operated at the origins of life and throughout evolutionary history. The new definition of life presented herein is formulated in a minimal manner and it is general enough that it does not distinguish between individual (metabolic) network and the collective (ecological) one. The newly proposed definition of life may be of interest for astrobiology, research into the origins of life or for efforts to produce synthetic or artificial life, and it furthermore may also have implications in the cognitive and computer sciences.
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Affiliation(s)
- Marko Vitas
- , Laze pri Borovnici 38, 1353 Borovnica, Slovenia.
| | - Andrej Dobovišek
- Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000, Maribor, Slovenia
- Faculty of Medicine, University of Maribor, Taborska ulica 6b, 2000, Maribor, Slovenia
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33
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Cafferty BJ, Wong ASY, Semenov SN, Belding L, Gmür S, Huck WTS, Whitesides GM. Robustness, Entrainment, and Hybridization in Dissipative Molecular Networks, and the Origin of Life. J Am Chem Soc 2019; 141:8289-8295. [PMID: 31035761 DOI: 10.1021/jacs.9b02554] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
How simple chemical reactions self-assembled into complex, robust networks at the origin of life is unknown. This general problem-self-assembly of dissipative molecular networks-is also important in understanding the growth of complexity from simplicity in molecular and biomolecular systems. Here, we describe how heterogeneity in the composition of a small network of oscillatory organic reactions can sustain (rather than stop) these oscillations, when homogeneity in their composition does not. Specifically, multiple reactants in an amide-forming network sustain oscillation when the environment (here, the space velocity) changes, while homogeneous networks-those with fewer reactants-do not. Remarkably, a mixture of two reactants of different structure-neither of which produces oscillations individually-oscillates when combined. These results demonstrate that molecular heterogeneity present in mixtures of reactants can promote rather than suppress complex behaviors.
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Affiliation(s)
- Brian J Cafferty
- Department of Chemistry and Chemical Biology , Harvard University 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Albert S Y Wong
- Department of Chemistry and Chemical Biology , Harvard University 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Sergey N Semenov
- Department of Chemistry and Chemical Biology , Harvard University 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Lee Belding
- Department of Chemistry and Chemical Biology , Harvard University 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Samira Gmür
- Department of Chemistry and Chemical Biology , Harvard University 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Wilhelm T S Huck
- Institute for Molecules and Materials , Radboud University Nijmegen , Heyendaalseweg 1 35 , 6525 AJ Nijmegen , The Netherlands
| | - George M Whitesides
- Department of Chemistry and Chemical Biology , Harvard University 12 Oxford Street , Cambridge , Massachusetts 02138 , United States.,Wyss Institute for Biologically Inspired Engineering , 60 Oxford Street , Cambridge , Massachusetts 02138 , United States.,Kalvi Institute for Bionano Science and Technology , Harvard University , 29 Oxford Street , Cambridge , Massachusetts 02138 , United States
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34
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Kim H, Smith HB, Mathis C, Raymond J, Walker SI. Universal scaling across biochemical networks on Earth. SCIENCE ADVANCES 2019; 5:eaau0149. [PMID: 30746442 PMCID: PMC6357746 DOI: 10.1126/sciadv.aau0149] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 12/06/2018] [Indexed: 06/09/2023]
Abstract
The application of network science to biology has advanced our understanding of the metabolism of individual organisms and the organization of ecosystems but has scarcely been applied to life at a planetary scale. To characterize planetary-scale biochemistry, we constructed biochemical networks using a global database of 28,146 annotated genomes and metagenomes and 8658 cataloged biochemical reactions. We uncover scaling laws governing biochemical diversity and network structure shared across levels of organization from individuals to ecosystems, to the biosphere as a whole. Comparing real biochemical reaction networks to random reaction networks reveals that the observed biological scaling is not a product of chemistry alone but instead emerges due to the particular structure of selected reactions commonly participating in living processes. We show that the topology of biochemical networks for the three domains of life is quantitatively distinguishable, with >80% accuracy in predicting evolutionary domain based on biochemical network size and average topology. Together, our results point to a deeper level of organization in biochemical networks than what has been understood so far.
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Affiliation(s)
- Hyunju Kim
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Harrison B. Smith
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Cole Mathis
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- Department of Physics, Arizona State University, Tempe, AZ, USA
| | - Jason Raymond
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Sara I. Walker
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
- ASU-SFI Center for Biosocial Complex Systems, Tempe, AZ, USA
- Blue Marble Space Institute of Science, Seattle, WA, USA
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35
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Abstract
Background This essay highlights critical aspects of the plausibility of pre-Darwinian evolution. It is based on a critical review of some better-known open, far-from-equilibrium system-based scenarios supposed to explain processes that took place before Darwinian evolution had emerged and that resulted in the origin of the first systems capable of Darwinian evolution. The researchers’ responses to eight crucial questions are reviewed. The majority of the researchers claim that there would have been an evolutionary continuity between chemistry and “biology”. A key question is how did this evolution begin before Darwinian evolution had begun? In other words the question is whether pre-Darwinian evolution is plausible. Results Strengths and weaknesses of the reviewed scenarios are presented. They are distinguished between metabolism-first, replicator-first and combined metabolism-replicator models. The metabolism-first scenarios show major issues, the worst concerns heredity and chirality. Although the replicator-first scenarios answer the heredity question they have their own problems, notably chirality. Among the reviewed combined metabolism-replicator models, one shows the fewest issues. In particular, it seems to answer the chiral question, and eventually implies Darwinian evolution from the very beginning. Its main hypothesis needs to be validated with experimental data. Conclusion From this critical review it is that the concept of “pre-Darwinian evolution” appears questionable, in particular because it is unlikely if not impossible that any evolution in complexity over time may work without multiplication and heritability allowing the emergence of genetically and ecologically diverse lineages on which natural selection may operate. Only Darwinian evolution could have led to such an evolution. Thus, Pre-Darwinian evolution is not plausible according to the author. Surely, the answer to the question posed in the title is a prerequisite to the understanding of the origin of Darwinian evolution. Reviewers This article was reviewed by Purificacion Lopez-Garcia, Anthony Poole, Doron Lancet, and Thomas Dandekar.
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36
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Johnson SS, Anslyn EV, Graham HV, Mahaffy PR, Ellington AD. Fingerprinting Non-Terran Biosignatures. ASTROBIOLOGY 2018; 18:915-922. [PMID: 29634318 PMCID: PMC6067094 DOI: 10.1089/ast.2017.1712] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 12/31/2017] [Indexed: 05/05/2023]
Abstract
Most strategies for life detection rely upon finding features known to be associated with terran life, such as particular classes of molecules. But life may be vastly different on other planets and moons, particularly as we expand our efforts to explore ocean worlds like Europa and Enceladus. We propose a new concept for life detection that harnesses the power of DNA sequencing to yield intricate informatics fingerprints, even for life that is not nucleic acid-based. The concept is based on the fact that folded nucleic acid structures (aptamers) have been shown to be capable of binding a wide variety of compounds, whether inorganic, organic, or polymeric, and irrespective of being from a biotic or abiotic source. Each nucleic acid sequence can be thought of as a code, and a combination of codes as a "fingerprint." Over multiple analytes, the "fingerprint" of a non-terran sample can be analyzed by chemometric protocols to provide a classifier of molecular patterns and complexity. Ultimately the chemometric fingerprints of living systems, which may differ significantly from nonliving systems, could provide an empirical, agnostic means of detecting life. Because nucleic acids are exponentially amplified by the polymerase chain reaction, even very small input signals could be translated into a robust readable output. The derived sequences could be identified by a small, portable sequencing device or by capture and optical imaging on a DNA microarray. Without presupposing any particular molecular framework, this agnostic approach to life detection could be used from Mars to the far reaches of the Solar System, all within the framework of an instrument drawing little heat and power. Key Words: Agnostic biosignatures-Astrobiology-Chemometrics-DNA sequencing-Life detection-Proximity ligation assay. Astrobiology 18, 915-922.
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Affiliation(s)
- Sarah S. Johnson
- Department of Biology, Georgetown University, Washington, DC
- Science, Technology, and International Affairs Program, Georgetown University, Washington, DC
| | - Eric V. Anslyn
- Department of Chemistry, The University of Texas at Austin, Austin, Texas
| | - Heather V. Graham
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Paul R. Mahaffy
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Andrew D. Ellington
- Institute for Cell and Molecular Biology, The University of Texas at Austin, Austin, Texas
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37
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Abstract
The emergence of functional cooperation between the three main classes of biomolecules - nucleic acids, peptides and lipids - defines life at the molecular level. However, how such mutually interdependent molecular systems emerged from prebiotic chemistry remains a mystery. A key hypothesis, formulated by Crick, Orgel and Woese over 40 year ago, posits that early life must have been simpler. Specifically, it proposed that an early primordial biology lacked proteins and DNA but instead relied on RNA as the key biopolymer responsible not just for genetic information storage and propagation, but also for catalysis, i.e. metabolism. Indeed, there is compelling evidence for such an 'RNA world', notably in the structure of the ribosome as a likely molecular fossil from that time. Nevertheless, one might justifiably ask whether RNA alone would be up to the task. From a purely chemical perspective, RNA is a molecule of rather uniform composition with all four bases comprising organic heterocycles of similar size and comparable polarity and pK a values. Thus, RNA molecules cover a much narrower range of steric, electronic and physicochemical properties than, e.g. the 20 amino acid side-chains of proteins. Herein we will examine the functional potential of RNA (and other nucleic acids) with respect to self-replication, catalysis and assembly into simple protocellular entities.
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38
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Huang S, Li F, Zhou JX, Qian H. Processes on the emergent landscapes of biochemical reaction networks and heterogeneous cell population dynamics: differentiation in living matters. J R Soc Interface 2018; 14:rsif.2017.0097. [PMID: 28490602 DOI: 10.1098/rsif.2017.0097] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/18/2017] [Indexed: 12/24/2022] Open
Abstract
The notion of an attractor has been widely employed in thinking about the nonlinear dynamics of organisms and biological phenomena as systems and as processes. The notion of a landscape with valleys and mountains encoding multiple attractors, however, has a rigorous foundation only for closed, thermodynamically non-driven, chemical systems, such as a protein. Recent advances in the theory of nonlinear stochastic dynamical systems and its applications to mesoscopic reaction networks, one reaction at a time, have provided a new basis for a landscape of open, driven biochemical reaction systems under sustained chemostat. The theory is equally applicable not only to intracellular dynamics of biochemical regulatory networks within an individual cell but also to tissue dynamics of heterogeneous interacting cell populations. The landscape for an individual cell, applicable to a population of isogenic non-interacting cells under the same environmental conditions, is defined on the counting space of intracellular chemical compositions x = (x1,x2, … ,xN ) in a cell, where xℓ is the concentration of the ℓth biochemical species. Equivalently, for heterogeneous cell population dynamics xℓ is the number density of cells of the ℓth cell type. One of the insights derived from the landscape perspective is that the life history of an individual organism, which occurs on the hillsides of a landscape, is nearly deterministic and 'programmed', while population-wise an asynchronous non-equilibrium steady state resides mostly in the lowlands of the landscape. We argue that a dynamic 'blue-sky' bifurcation, as a representation of Waddington's landscape, is a more robust mechanism for a cell fate decision and subsequent differentiation than the widely pictured pitch-fork bifurcation. We revisit, in terms of the chemostatic driving forces upon active, living matter, the notions of near-equilibrium thermodynamic branches versus far-from-equilibrium states. The emergent landscape perspective permits a quantitative discussion of a wide range of biological phenomena as nonlinear, stochastic dynamics.
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Affiliation(s)
- Sui Huang
- Institute for Systems Biology, 401 Terry Avenue N., Seattle, WA 98109, USA
| | - Fangting Li
- School of Physics, Center for Quantitative Biology, Peking University, Beijing 100871, People's Republic of China
| | - Joseph X Zhou
- Institute for Systems Biology, 401 Terry Avenue N., Seattle, WA 98109, USA
| | - Hong Qian
- Department of Applied Mathematics, University of Washington, Seattle, WA 98195, USA
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39
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Walker SI, Packard N, Cody GD. Re-conceptualizing the origins of life. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2016.0337. [PMID: 29133439 PMCID: PMC5686397 DOI: 10.1098/rsta.2016.0337] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Over the last several hundred years of scientific progress, we have arrived at a deep understanding of the non-living world. We have not yet achieved an analogous, deep understanding of the living world. The origins of life is our best chance at discovering scientific laws governing life, because it marks the point of departure from the predictable physical and chemical world to the novel, history-dependent living world. This theme issue aims to explore ways to build a deeper understanding of the nature of biology, by modelling the origins of life on a sufficiently abstract level, starting from prebiotic conditions on Earth and possibly on other planets and bridging quantitative frameworks approaching universal aspects of life. The aim of the editors is to stimulate new directions for solving the origins of life. The present introduction represents the point of view of the editors on some of the most promising future directions.This article is part of the themed issue 'Reconceptualizing the origins of life'.
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Affiliation(s)
- Sara I Walker
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- Blue Marble Space Institute for Science, Seattle, WA, USA
| | | | - G D Cody
- Geophysical Laboratory, Carnegie Institution for Science, Washington, DC, USA
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Marshall SM, Murray ARG, Cronin L. A probabilistic framework for identifying biosignatures using Pathway Complexity. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2016.0342. [PMID: 29133442 PMCID: PMC5686400 DOI: 10.1098/rsta.2016.0342] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/18/2017] [Indexed: 05/18/2023]
Abstract
One thing that discriminates living things from inanimate matter is their ability to generate similarly complex or non-random structures in a large abundance. From DNA sequences to folded protein structures, living cells, microbial communities and multicellular structures, the material configurations in biology can easily be distinguished from non-living material assemblies. Many complex artefacts, from ordinary bioproducts to human tools, though they are not living things, are ultimately produced by biological processes-whether those processes occur at the scale of cells or societies, they are the consequences of living systems. While these objects are not living, they cannot randomly form, as they are the product of a biological organism and hence are either technological or cultural biosignatures. A generalized approach that aims to evaluate complex objects as possible biosignatures could be useful to explore the cosmos for new life forms. However, it is not obvious how it might be possible to create such a self-contained approach. This would require us to prove rigorously that a given artefact is too complex to have formed by chance. In this paper, we present a new type of complexity measure, which we call 'Pathway Complexity', that allows us not only to threshold the abiotic-biotic divide, but also to demonstrate a probabilistic approach based on object abundance and complexity which can be used to unambiguously assign complex objects as biosignatures. We hope that this approach will not only open up the search for biosignatures beyond the Earth, but also allow us to explore the Earth for new types of biology, and to determine when a complex chemical system discovered in the laboratory could be considered alive.This article is part of the themed issue 'Reconceptualizing the origins of life'.
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Affiliation(s)
| | | | - Leroy Cronin
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
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C G N, LaBar T, Hintze A, Adami C. Origin of life in a digital microcosm. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2016.0350. [PMID: 29133448 PMCID: PMC5686406 DOI: 10.1098/rsta.2016.0350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/31/2017] [Indexed: 05/09/2023]
Abstract
While all organisms on Earth share a common descent, there is no consensus on whether the origin of the ancestral self-replicator was a one-off event or whether it only represented the final survivor of multiple origins. Here, we use the digital evolution system Avida to study the origin of self-replicating computer programs. By using a computational system, we avoid many of the uncertainties inherent in any biochemical system of self-replicators (while running the risk of ignoring a fundamental aspect of biochemistry). We generated the exhaustive set of minimal-genome self-replicators and analysed the network structure of this fitness landscape. We further examined the evolvability of these self-replicators and found that the evolvability of a self-replicator is dependent on its genomic architecture. We also studied the differential ability of replicators to take over the population when competed against each other, akin to a primordial-soup model of biogenesis, and found that the probability of a self-replicator outcompeting the others is not uniform. Instead, progenitor (most-recent common ancestor) genotypes are clustered in a small region of the replicator space. Our results demonstrate how computational systems can be used as test systems for hypotheses concerning the origin of life.This article is part of the themed issue 'Reconceptualizing the origins of life'.
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Affiliation(s)
- Nitash C G
- Department of Computer Science and Engineering, Michigan State University, East Lansing, MI 48824, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI 48824, USA
| | - Thomas LaBar
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI 48824, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
- Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI 48824, USA
| | - Arend Hintze
- Department of Computer Science and Engineering, Michigan State University, East Lansing, MI 48824, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI 48824, USA
- Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI 48824, USA
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Christoph Adami
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI 48824, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
- Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA
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Walker SI. Origins of life: a problem for physics, a key issues review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:092601. [PMID: 28593934 DOI: 10.1088/1361-6633/aa7804] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The origins of life stands among the great open scientific questions of our time. While a number of proposals exist for possible starting points in the pathway from non-living to living matter, these have so far not achieved states of complexity that are anywhere near that of even the simplest living systems. A key challenge is identifying the properties of living matter that might distinguish living and non-living physical systems such that we might build new life in the lab. This review is geared towards covering major viewpoints on the origin of life for those new to the origin of life field, with a forward look towards considering what it might take for a physical theory that universally explains the phenomenon of life to arise from the seemingly disconnected array of ideas proposed thus far. The hope is that a theory akin to our other theories in fundamental physics might one day emerge to explain the phenomenon of life, and in turn finally permit solving its origins.
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Affiliation(s)
- Sara Imari Walker
- School of Earth and Space Exploration and Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, United States of America. Blue Marble Space Institute of Science, Seattle, WA, United States of America
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Doran D, Rodriguez-Garcia M, Turk-MacLeod R, Cooper GJT, Cronin L. A recursive microfluidic platform to explore the emergence of chemical evolution. Beilstein J Org Chem 2017; 13:1702-1709. [PMID: 28904613 PMCID: PMC5564272 DOI: 10.3762/bjoc.13.164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/01/2017] [Indexed: 11/23/2022] Open
Abstract
We propose that a chemically agnostic approach to explore the origin of life, using an automated recursive platform based on droplet microfluidics, could be used to induce artificial chemical evolution by iterations of growth, speciation, selection, and propagation. To explore this, we set about designing an open source prototype of a fully automated evolution machine, comprising seven modules. These modules are a droplet generator, droplet transfer, passive and active size sorting, splitter, incubation chamber, reservoir, and injectors, all run together via a LabVIEWTM program integration system. Together we aim for the system to be used to drive cycles of droplet birth, selection, fusion, and propagation. As a proof of principle, in addition to the working individual modules, we present data showing the osmotic exchange of glycylglycine containing and pure aqueous droplets, showing that the fittest droplets exhibit higher osomolarity relative to their neighbours, and increase in size compared to their neighbours. This demonstrates the ability of our platform to explore some different physicochemical conditions, combining the efficiency and unbiased nature of automation with our ability to select droplets as functional units based on simple criteria.
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Affiliation(s)
- David Doran
- WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Marc Rodriguez-Garcia
- WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Rebecca Turk-MacLeod
- WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Geoffrey J T Cooper
- WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Leroy Cronin
- WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
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Matysiak BM, Nowak P, Cvrtila I, Pappas CG, Liu B, Komáromy D, Otto S. Antiparallel Dynamic Covalent Chemistries. J Am Chem Soc 2017; 139:6744-6751. [PMID: 28440073 PMCID: PMC5438195 DOI: 10.1021/jacs.7b02575] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The ability to design reaction networks with high, but addressable complexity is a necessary prerequisite to make advanced functional chemical systems. Dynamic combinatorial chemistry has proven to be a useful tool in achieving complexity, however with some limitations in controlling it. Herein we introduce the concept of antiparallel chemistries, in which the same functional group can be channeled into one of two reversible chemistries depending on a controllable parameter. Such systems allow both for achieving complexity, by combinatorial chemistry, and addressing it, by switching from one chemistry to another by controlling an external parameter. In our design the two antiparallel chemistries are thiol-disulfide exchange and thio-Michael addition, sharing the thiol as the common building block. By means of oxidation and reduction the system can be reversibly switched from predominantly thio-Michael chemistry to predominantly disulfide chemistry, as well as to any intermediate state. Both chemistries operate in water, at room temperature, and at mildly basic pH, which makes them a suitable platform for further development of systems chemistry.
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Affiliation(s)
- Bartosz M Matysiak
- Centre for Systems Chemistry, Stratingh Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Faculty of Chemistry, University of Warsaw , Pasteura 1, 02-093 Warsaw, Poland
| | - Piotr Nowak
- Centre for Systems Chemistry, Stratingh Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ivica Cvrtila
- Centre for Systems Chemistry, Stratingh Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Charalampos G Pappas
- Centre for Systems Chemistry, Stratingh Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Bin Liu
- Centre for Systems Chemistry, Stratingh Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Dávid Komáromy
- Centre for Systems Chemistry, Stratingh Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Sijbren Otto
- Centre for Systems Chemistry, Stratingh Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Kee TP. Reaction: Life, Origins, and the System. Chem 2017. [DOI: 10.1016/j.chempr.2017.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Greenbaum B, Pargellis AN. Self-Replicators Emerge from a Self-Organizing Prebiotic Computer World. ARTIFICIAL LIFE 2017; 23:318-342. [PMID: 28786722 DOI: 10.1162/artl_a_00234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Amoeba, a computer platform inspired by the Tierra system, is designed to study the generation of self-replicating sequences of machine operations (opcodes) from a prebiotic world initially populated by randomly selected opcodes. Point mutations drive opcode sequences to become more fit as they compete for memory and CPU time. Significant features of the Amoeba system include the lack of artificial encapsulation (there is no write protection) and a computationally universal opcode basis set. Amoeba now includes two additional features: pattern-based addressing and injecting entropy into the system. It was previously thought such changes would make it highly unlikely that an ancestral replicator could emerge from a fortuitous combination of randomly selected opcodes. Instead, Amoeba shows a far richer emergence, exhibiting a self-organization phase followed by the emergence of self-replicators. First, the opcode basis set becomes biased. Second, short opcode building blocks are propagated throughout memory space. Finally, prebiotic building blocks can combine to form self-replicators. Self-organization is quantified by measuring the evolution of opcode frequencies, the size distribution of sequences, and the mutual information of opcode pairs.
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A framework towards understanding mesoscopic phenomena: Emergent unpredictability, symmetry breaking and dynamics across scales. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.10.059] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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