Autogenesis: From Constraint to Regulation

Terrence W. Deacon's picture

Terrence W. Deacon
Anthropology Department Chair
University of California
Berkeley
Presented in the Embryo Physics Course, March 20, 2013

Abstract

The origin of living dynamics required an evasion of second law degradation effects by maintaining critical dynamical and structural constraints. This is accomplished by synthesizing new components for replacement and reproduction and regulating these interactions with respect to critical intrinsic requirements and extrinsic conditions. Model systems for life’s origin that primarily focus on molecular replication (e.g. RNA-world), or co-production of components (e.g. autocatalysis, hypercycles, autopoiesis), or physical containment of molecular interactions (e.g. protocells) fail to distinguish between constrained chemistry and regulated metabolism. For this reason they do not address the question of how living processes first emerge from simpler constraints on molecular interactions. And those models that merely assume all three of these features (e.g. chemoton) both fail to address the origin of this complexity and how it is regulated. I begin with a simple molecular model system consisting of coupled reciprocal catalysis and self-assembly in which one of the catalytic bi-products tends to spontaneously self-assemble into a containing shell (analogous to a viral capsule). I term this dynamical relationship autogenesis because it is self-reconstituting in response to degradation. Self-reconstitution (and reproduction) is made possible by the fact that each of these linked self-organizing processes generates boundary constraints that promote and limit the other, and because this synergy thereby becomes embodied as a persistent rate-independent and substrate-indifferent higher order constraint on component constraint generation processes. It is proposed that this formal synergy is necessary and sufficient to constitute regulation as opposed to mere constraint. Two minor elaborations of this simple model system demonstrate that this simplest form of regulation can be the foundation for the evolution of two higher-order forms: cybernetic and template-based regulation.

Presentation

/files/presentations/Deacon2013.pdf

Biography

http://anthropology.berkeley.edu/users/terrence-w-deacon

Links


Comments

2 responses to “Autogenesis: From Constraint to Regulation”

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  1. Dear Terrence,

    Thank you very much for your stimulating talk I just attended to. My computer crashed during the discussion. So, I had two suggestions for you to go further, and one question:

    – Have you heard about chemical organization theory? It is a relatively new framework to model reaction networks. It is a very elegant and clean mathematical (algebraic) framework. I suspect this is exactly what you are looking for. See e.g. :

    Dittrich, P., J. Ziegler, and W. Banzhaf. 2001. “Artificial Chemistries-a Review.” Artificial Life 7 (3): 225–275.

    Dittrich, P., and L. Winter. 2005. “Reaction Networks as a Formal Mechanism to Explain Social Phenomena.” In Proc. Fourth Int. Workshop on Agent-Based Approaches in Economics and Social Complex Systems (AESCS 2005), 9–13. http://users.minet.uni-jena.de/~dittrich/p/DW2005.pdf.

    – Are you familiar with metasystem transitions theory? It is a classical way to model constraints on constraints, and the emergence of new control levels. See e.g.:

    Turchin, V. 1977. The Phenomenon of Science. New York: Columbia University Press. http://pespmc1.vub.ac.be/POS/TurPOS.pdf.

    Heylighen F. (1995): “(Meta)systems as Constraints on Variation: a classification and natural history of metasystem transitions”, World Futures: the Journal of General Evolution 45, p. 59-85. http://pespmc1.vub.ac.be/Papers/MST-ConVar.pdf (A metasystem occurs when the constraint become a variable in a constrained way).

    – I gave a talk last week about extraterrestrial life and how to recognize it (http://embryogenesisexplained.com/2013/03/the-starivore-hypothesis.html). I speculate that some binary star systems could be advanced living forms. How could we test if they display morphodynamics or teleodynamics? What do you think?

    Best,
    Clément Vidal.
    ________________________________________
    http://clement.vidal.philosophons.com
    Co-Director, Evo Devo Universe Community
    http://www.evodevouniverse.com
    Researcher, Global Brain Institute
    http://www.globalbraininstitute.org/
    Centrum Leo Apostel, Vrije Universiteit Brussel
    Krijgskundestraat 33. B-1160 Brussels, Belgium
    Tel: +32 2 640 67 37 | Fax: +32 2 644 07 44

  2. Dear Terrence,

    I enjoyed your talk yesterday and agree with most of your conclusions. Your research contributes to the integration of cybernetics with biology and semiotics, which I appreciate greatly because I am myself a “biosemiotician” and work in a similar direction. But here I will focus on issues where I disagree with you:

    (1) You emphasize “constraints” or “absence” as in your book “Incomplete nature”. This is a purely physical approach which assumes that the nature develops according to it’s internal “laws”, and the only thing that can be changed is to assemble constraints to this motion. An alternative approach is that there are no “laws of nature” but only models that only approximate the dynamics of the real world. Dynamic models become less accurate as the time interval increases. Then, it may be more meaningful to describe living agents using terms “sign”, “choice”, or “encoded invention”. In other words you describe organisms in a negative way (as “half-empty” glass), and I suggest that positive description (“half-full” glass) may be more meaningful. It is also possible that these two approaches are complementary and equally productive, but it is a mistake to see life only from the negative perspective.

    (2) Your slide “Reciprocal catalysis (autocatalytic set)” is an example of autocatalytic degradation because the system requires the influx of more complex molecules (a and d) than it produces (f and b). Obviously autocatalytic degradation cannot lead to the increase in complexity. I suggest to make a figure that shows autocatalytic synthesis where products are more complex than resources.

    (3) I like your statement “Natural selection “captures” self-organizing effects by preserving genetic constraints that regulate the conditions that favor their spontaneous formation” (although instead of “constraints” I would use “signs”). This view is a an important step forward compared to Kauffman who thought that self-organization is a free gift of nature. Do you have this thought published and where?

    (4) I know your “autocell” model but disagree that life could have started from self-assembly of polymeric molecules (polypeptydes, nucleic acids, etc.). To make these polymers the primordial system needs monomers (aminoacids, nucleic bases,…) which are extremely rare in the abiotic nature. Thus, I proposed a model of life origin from simpler monomer molecules that have heritable functions http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680650/pdf/ijms-10-01838.pdf

    (5) I did not understand your idea on “limits to autogenic complexity”. I don’t think that side reactions pose a big threat to the general trend of complexity increase. I examined this issue in my paper http://home.comcast.net/~sharov/pdf/GenomeIncrease.pdf Please, explain your statement.