Living systems are life forms (or, more colloquially known as living things) treated as a system. They are said to be open self-organizing and said to interact with their environment. These systems are maintained by flows of information, energy and matter. Multiple theories of living systems have been proposed. Such theories attempt to map general principles for how all living systems work.

A presentation on information flow in living systems

Context

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Some scientists have proposed in the last few decades that a general theory of living systems is required to explain the nature of life.[1] Such a general theory would arise out of the ecological and biological sciences and attempt to map general principles for how all living systems work. Instead of examining phenomena by attempting to break things down into components, a general living systems theory explores phenomena in terms of dynamic patterns of the relationships of organisms with their environment.[2]

Theories

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Miller's open systems

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James Grier Miller's living systems theory is a general theory about the existence of all living systems, their structure, interaction, behavior and development, intended to formalize the concept of life. According to Miller's 1978 book Living Systems, such a system must contain each of twenty "critical subsystems" defined by their functions. Miller considers living systems as a type of system. Below the level of living systems, he defines space and time, matter and energy, information and entropy, levels of organization, and physical and conceptual factors, and above living systems ecological, planetary and solar systems, galaxies, etc.[3][4][5] Miller's central thesis is that the multiple levels of living systems (cells, organs, organisms, groups, organizations, societies, supranational systems) are open systems composed of critical and mutually-dependent subsystems that process inputs, throughputs, and outputs of energy and information.[6][7][8] Seppänen (1998) says that Miller applied general systems theory on a broad scale to describe all aspects of living systems.[9] Bailey states that Miller's theory is perhaps the "most integrative" social systems theory,[10] clearly distinguishing between matter–energy-processing and information-processing, showing how social systems are linked to biological systems. LST analyzes the irregularities or "organizational pathologies" of systems functioning (e.g., system stress and strain, feedback irregularities, information–input overload). It explicates the role of entropy in social research while it equates negentropy with information and order. It emphasizes both structure and process, as well as their interrelations.[11]

Lovelock's Gaia hypothesis

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The idea that Earth is alive is found in philosophy and religion, but the first scientific discussion of it was by the Scottish geologist James Hutton. In 1785, he stated that Earth was a superorganism and that its proper study should be physiology.[12]: 10  The Gaia hypothesis, proposed in the 1960s by James Lovelock, suggests that life on Earth functions as a single organism that defines and maintains environmental conditions necessary for its survival.[13][14]

Morowitz's property of ecosystems

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A systems view of life treats environmental fluxes and biological fluxes together as a "reciprocity of influence,"[15] and a reciprocal relation with environment is arguably as important for understanding life as it is for understanding ecosystems. As Harold J. Morowitz (1992) explains it, life is a property of an ecological system rather than a single organism or species.[16] He argues that an ecosystemic definition of life is preferable to a strictly biochemical or physical one. Robert Ulanowicz (2009) highlights mutualism as the key to understand the systemic, order-generating behaviour of life and ecosystems.[17]

Rosen's complex systems biology

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Robert Rosen devoted a large part of his career, from 1958[18] onwards, to developing a comprehensive theory of life as a self-organizing complex system, "closed to efficient causation". He defined a system component as "a unit of organization; a part with a function, i.e., a definite relation between part and whole." He identified the "nonfractionability of components in an organism" as the fundamental difference between living systems and "biological machines." He summarised his views in his book Life Itself.[19]

Complex systems biology is a field of science that studies the emergence of complexity in functional organisms from the viewpoint of dynamic systems theory.[20] The latter is also often called systems biology and aims to understand the most fundamental aspects of life. A closely related approach, relational biology, is concerned mainly with understanding life processes in terms of the most important relations, and categories of such relations among the essential functional components of organisms; for multicellular organisms, this has been defined as "categorical biology", or a model representation of organisms as a category theory of biological relations, as well as an algebraic topology of the functional organisation of living organisms in terms of their dynamic, complex networks of metabolic, genetic, and epigenetic processes and signalling pathways.[21][22] Related approaches focus on the interdependence of constraints, where constraints can be either molecular, such as enzymes, or macroscopic, such as the geometry of a bone or of the vascular system.[23]

Bernstein, Byerly and Hopf's Darwinian dynamic

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Harris Bernstein and colleagues argued in 1983 that the evolution of order in living systems and certain physical systems obeys a common fundamental principle termed the Darwinian dynamic. This was formulated by first considering how macroscopic order is generated in a simple non-biological system far from thermodynamic equilibrium, and then extending consideration to short, replicating RNA molecules. The underlying order-generating process was concluded to be basically similar for both types of systems.[24][25]

Gerard Jagers' operator theory

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Gerard Jagers' operator theory proposes that life is a general term for the presence of the typical closures found in organisms; the typical closures are a membrane and an autocatalytic set in the cell[26] and that an organism is any system with an organisation that complies with an operator type that is at least as complex as the cell.[27][28][29][30] Life can be modelled as a network of inferior negative feedbacks of regulatory mechanisms subordinated to a superior positive feedback formed by the potential of expansion and reproduction.[31]

Kauffman's multi-agent system

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Stuart Kauffman defines a living system as an autonomous agent or a multi-agent system capable of reproducing itself or themselves, and of completing at least one thermodynamic work cycle.[32] This definition is extended by the evolution of novel functions over time.[33]

Budisa, Kubyshkin and Schmidt's four pillars

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Definition of cellular life according to Budisa, Kubyshkin and Schmidt

Budisa, Kubyshkin and Schmidt defined cellular life as an organizational unit resting on four pillars/cornerstones: (i) energy, (ii) metabolism, (iii) information and (iv) form. This system is able to regulate and control metabolism and energy supply and contains at least one subsystem that functions as an information carrier (genetic information). Cells as self-sustaining units are parts of different populations that are involved in the unidirectional and irreversible open-ended process known as evolution.[34]

See also

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  • Artificial life – Field of study
  • Autonomous Agency Theory – viable system theory
  • Autopoiesis – Systems concept which entails automatic reproduction and maintenance
  • Biological organization – Hierarchy of complex structures and systems within biological sciences
  • Biological systems – Complex network which connects several biologically relevant entities
  • Complex systems – System composed of many interacting components
  • Earth system science – Scientific study of the Earth's spheres and their natural integrated systems
  • Extraterrestrial life – Life not on Earth
  • Information metabolism – Psychological theory of interaction between biological organisms and their environment
  • Organism – Individual living life form
  • Spome – Hypothetical matter-closed, energy-open life support system
  • Systems biology – Computational and mathematical modeling of complex biological systems
  • Systems theory – Interdisciplinary study of systems
  • Viable System Theory – concerns cybernetic processes in relation to the development/evolution of dynamical systems

References

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  1. ^ Clealand, Carol E.; Chyba, Christopher F. (8 October 2007). "Does 'Life' Have a Definition?". In Woodruff, T. Sullivan; Baross, John (eds.). Planets and Life: The Emerging Science of Astrobiology. Cambridge University Press. In the absence of such a theory, we are in a position analogous to that of a 16th-century investigator trying to define 'water' in the absence of molecular theory. [...] Without access to living things having a different historical origin, it is difficult and perhaps ultimately impossible to formulate an adequately general theory of the nature of living systems
  2. ^ Brown, Molly Young (2002). "Patterns, Flows, and Interrelationship". Archived from the original on 8 January 2009. Retrieved 27 June 2009.
  3. ^ Miller, James Grier (1978). Living Systems. New York: McGraw-Hill. ISBN 978-0070420151.
  4. ^ Seppänen, Jouko (1998). "Systems ideology in human and social sciences". In Altmann, G.; Koch, W.A. (eds.). Systems: New paradigms for the human sciences. Berlin: Walter de Gruyter. pp. 180–302.
  5. ^ Járos, György (2000). "Living Systems Theory of James Grier Miller and teleonics". Systems Research and Behavioral Science. 17 (3). Wiley: 289–300. doi:10.1002/(sici)1099-1743(200005/06)17:3<289::aid-sres333>3.0.co;2-z. ISSN 1092-7026.
  6. ^ (Miller, 1978, p. 1025)
  7. ^ Parent, Elaine (1996). "The Living Systems Theory of James Grier Miller". The Primer Project. Retrieved 20 September 2023.
  8. ^ "The Earth as a System". Primer project ISSS. Retrieved 20 September 2023.
  9. ^ Seppänen 1998, pp. 197–198.
  10. ^ Kenneth D. Bailey 2006, pp.292–296.
  11. ^ Kenneth D. Bailey, 1994, pp. 209–210.
  12. ^ Lovelock, James (1979). Gaia: A New Look at Life on Earth. Oxford University Press. ISBN 978-0-19-286030-9.
  13. ^ Lovelock, J.E. (1965). "A physical basis for life detection experiments". Nature. 207 (7): 568–570. Bibcode:1965Natur.207..568L. doi:10.1038/207568a0. PMID 5883628. S2CID 33821197.
  14. ^ Lovelock, James. "Geophysiology". Papers by James Lovelock. Archived from the original on 6 May 2007. Retrieved 1 October 2009.
  15. ^ Fiscus, Daniel A. (April 2002). "The Ecosystemic Life Hypothesis". Bulletin of the Ecological Society of America. Archived from the original on 6 August 2009. Retrieved 28 August 2009.
  16. ^ Morowitz, Harold J. (1992). Beginnings of cellular life: metabolism recapitulates biogenesis. Yale University Press. ISBN 978-0-300-05483-5.
  17. ^ Ulanowicz, Robert W.; Ulanowicz, Robert E. (2009). A third window: natural life beyond Newton and Darwin. Templeton Foundation Press. ISBN 978-1-59947-154-9.
  18. ^ Rosen, Robert (1958). "A relational theory of biological systems". The Bulletin of Mathematical Biophysics. 20 (3): 245–260. doi:10.1007/bf02478302.
  19. ^ Robert, Rosen (1991). Life Itself: A Comprehensive Inquiry into the Nature, Origin, and Fabrication of Life. New York: Columbia University Press. ISBN 978-0-231-07565-7.
  20. ^ Baianu, I.C. (2006). "Robert Rosen's Work and Complex Systems Biology". Axiomathes. 16 (1–2): 25–34. doi:10.1007/s10516-005-4204-z. S2CID 4673166.
  21. ^ * Rosen, Robert (1958a). "A Relational Theory of Biological Systems". Bulletin of Mathematical Biophysics. 20 (3): 245–260. doi:10.1007/bf02478302.
  22. ^ * Rosen, R. (1958b). "The Representation of Biological Systems from the Standpoint of the Theory of Categories". Bulletin of Mathematical Biophysics. 20 (4): 317–341. doi:10.1007/bf02477890.
  23. ^ Montévil, Maël; Mossio, Matteo (7 May 2015). "Biological organisation as closure of constraints". Journal of Theoretical Biology. 372: 179–191. Bibcode:2015JThBi.372..179M. CiteSeerX 10.1.1.701.3373. doi:10.1016/j.jtbi.2015.02.029. PMID 25752259. S2CID 4654439. Archived from the original on 17 November 2017.
  24. ^ Bernstein, Harris; Byerly, Henry C.; Hopf, Frederick A.; Michod, Richard A.; Vemulapalli, G. Krishna (June 1983). "The Darwinian Dynamic". The Quarterly Review of Biology. 58 (2): 185. doi:10.1086/413216. JSTOR 2828805. S2CID 83956410.
  25. ^ Michod, Richard E. (2000). Darwinian Dynamics: Evolutionary Transitions in Fitness and Individuality. Princeton: Princeton University Press. ISBN 978-0-691-05011-9.
  26. ^ Jagers, Gerard (2012). The Pursuit of Complexity: The Utility of Biodiversity from an Evolutionary Perspective. KNNV Publishing. pp. 27–29, 87–88, 94–96. ISBN 978-90-5011-443-1.
  27. ^ Jagers Op Akkerhuis, Gerard A. J. M. (2010). "Towards a Hierarchical Definition of Life, the Organism, and Death". Foundations of Science. 15 (3): 245–262. doi:10.1007/s10699-010-9177-8. S2CID 195282529.
  28. ^ Jagers Op Akkerhuis, Gerard (2011). "Explaining the Origin of Life is not Enough for a Definition of Life". Foundations of Science. 16 (4): 327–329. doi:10.1007/s10699-010-9209-4. S2CID 195284978.
  29. ^ Jagers Op Akkerhuis, Gerard A. J. M. (2012). "The Role of Logic and Insight in the Search for a Definition of Life". Journal of Biomolecular Structure and Dynamics. 29 (4): 619–620. doi:10.1080/073911012010525006. PMID 22208258. S2CID 35426048. Archived from the original on 16 April 2021. Retrieved 16 April 2021.
  30. ^ Jagers, Gerald (2012). "Contributions of the Operator Hierarchy to the Field of Biologically Driven Mathematics and Computation". In Ehresmann, Andree C.; Simeonov, Plamen L.; Smith, Leslie S. (eds.). Integral Biomathics. Springer. ISBN 978-3-642-28110-5.
  31. ^ Korzeniewski, Bernard (7 April 2001). "Cybernetic formulation of the definition of life". Journal of Theoretical Biology. 209 (3): 275–286. Bibcode:2001JThBi.209..275K. doi:10.1006/jtbi.2001.2262. PMID 11312589.
  32. ^ Kaufmann, Stuart (2004). "Autonomous agents". In Barrow, John D.; Davies, P.C.W.; Harper, Jr., C.L. (eds.). Science and Ultimate Reality. pp. 654–666. doi:10.1017/CBO9780511814990.032. ISBN 978-0-521-83113-0.
  33. ^ Longo, Giuseppe; Montévil, Maël; Kauffman, Stuart (1 January 2012). "No entailing laws, but enablement in the evolution of the biosphere". Proceedings of the 14th annual conference companion on Genetic and evolutionary computation. GECCO '12. pp. 1379–1392. arXiv:1201.2069. Bibcode:2012arXiv1201.2069L. CiteSeerX 10.1.1.701.3838. doi:10.1145/2330784.2330946. ISBN 978-1-4503-1178-6. S2CID 15609415. Archived from the original on 11 May 2017.
  34. ^ Budisa, Nediljko; Kubyshkin, Vladimir; Schmidt, Markus (22 April 2020). "Xenobiology: A Journey towards Parallel Life Forms". ChemBioChem. 21 (16): 2228–2231. doi:10.1002/cbic.202000141. PMID 32323410.

Further reading

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  • Kenneth D. Bailey, (1994). Sociology and the new systems theory: Toward a theoretical synthesis. Albany, NY: SUNY Press.
  • Kenneth D. Bailey (2006). Living systems theory and social entropy theory. Systems Research and Behavioral Science, 22, 291–300.
  • James Grier Miller, (1978). Living systems. New York: McGraw-Hill. ISBN 0-87081-363-3
  • Miller, J.L., & Miller, J.G. (1992). Greater than the sum of its parts: Subsystems which process both matter-energy and information. Behavioral Science, 37, 1–38.
  • Humberto Maturana (1978), "Biology of language: The epistemology of reality," in Miller, George A., and Elizabeth Lenneberg (eds.), Psychology and Biology of Language and Thought: Essays in Honor of Eric Lenneberg. Academic Press: 27-63.
  • Jouko Seppänen, (1998). Systems ideology in human and social sciences. In G. Altmann & W.A. Koch (Eds.), Systems: New paradigms for the human sciences (pp. 180–302). Berlin: Walter de Gruyter.
  • James R. Simms (1999). Principles of Quantitative Living Systems Science. Dordrecht: Kluwer Academic. ISBN 0-306-45979-5
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