Papers by Terrence Deacon
Biological Theory, Jun 1, 2006
A simple molecular system ("autocell") is described consisting of the reciprocal linkage between ... more A simple molecular system ("autocell") is described consisting of the reciprocal linkage between an autocatalytic cycle and a self-assembling encapsulation process where the molecular constituents for the capsule are products of the autocatalysis. In a molecular environment sufficiently rich in the substrates, capsule growth will also occur with high predictability. Growth to closure will be most probable in the vicinity of the most prolific autocatalysis and will thus tend to spontaneously enclose supportive catalysts within the capsule interior. If subsequently disrupted in the presence of new substrates, the released components will initiate production of additional catalytic and capsule components that will spontaneously reassemble into one or more autocell replicas, thereby reconstituting and sometimes reproducing the original. In a diverse molecular environment, cycles of disruption and enclosure will cause autocells to incidentally encapsulate other molecules as well as reactive substrates. To the extent that any captured molecule can be incorporated into the autocatalytic process by virtue of structural degeneracy of the catalytic binding sites, the altered autocell will incorporate the new type of component into subsequent replications. Such altered autocells will be progenitors of "lineages" with variant characteristics that will differentially propagate with respect to the availability of commonly required substrates. Autocells are susceptible to a limited form of evolution, capable of leading to more efficient, more environmentally fitted, and more complex forms. This provides a simple demonstration of the plausibility of openended reproduction and evolvability without self-replicating template molecules (e.g., nucleic acids) or maintenance of persistent nonequilibrium chemistry. This model identifies an intermediate domain between prebiotic and biotic systems and bridges the gap from nonequilibrium thermodynamics to life.
Cognitive Semiotics, Sep 1, 2007
A scientifically adequate theory of semiotic processes must ultimately be founded on a theory of ... more A scientifically adequate theory of semiotic processes must ultimately be founded on a theory of information that can unify the physical, biological, cognitive, and computational uses of the concept. Unfortunately, no such unification exists, and more importantly, the causal status of informational content remains ambiguous as a result. Lacking this grounding, semiotic theories have tended to be predominantly phenomenological taxonomies rather than dynamical explanations of the representational processes of natural systems. This paper argues that the problem of information that prevents the development of a scientific semiotic theory is the necessity of analyzing it as a negative relationship: defined with respect to absence. This is cryptically implicit in concepts of design and function in biology, acknowledged in psychological and philosophical accounts of intentionality and content, and is explicitly formulated in the mathematical theory of communication (aka "information theory"). Beginning from the base established by Claude Shannon, which otherwise ignores issues of content, reference, and evaluation, this two part essay explores its relationship to two other higher-order theories that are also explicitly based on an analysis of absence: Boltzmann's theory of thermodynamic entropy (in Part I) and Darwin's theory of natural selection (in Part II). This comparison demonstrates that these theories are both formally homologous and hierarchically interdependent. Their synthesis into a general theory of entropy and information provides the necessary grounding for theories of function and semiosis. I T.W. DEACON Truth is something we can attempt to doubt, and then perhaps, after much exertion, discover that part of the doubt is unjustified.
Oxford University Press eBooks, Sep 2, 2009
Elsevier eBooks, 2017
Encephalization is one of the defining features of the primate Order, but patterns of brain/body ... more Encephalization is one of the defining features of the primate Order, but patterns of brain/body scaling in different primate radiations are caused by different developmental mechanisms. All primates share a novel pattern of fetal encephalization that is linked to exceptionally slow rates of postcranial body growth during every stage of ontogeny. By contrast, additional grade shifts in relative brain size within anthropoid radiations and humans are caused by brain size increases, including both neocortical expansion and coordinated increases in all brain structures according to allometric principles.
Journal of the Royal Anthropological Institute, Mar 1, 1999
This revolutionary book provides fresh answers to long-standing questions of human origins and co... more This revolutionary book provides fresh answers to long-standing questions of human origins and consciousness. Drawing on his breakthrough research in comparative neuroscience, Terrence Deacon offers a wealth of insights into the significance of symbolic thinking: from the co-evolutionary exchange between language and brains over two million years of hominid evolution to the ethical repercussions that followed man's newfound access to other people's thoughts and emotions. Informing these insights is a new understanding of how Darwinian processes underlie the brain's development and function as well as its evolution. In contrast to much contemporary neuroscience that treats the brain as no more or less than a computer, Deacon provides a new clarity of vision into the mechanism of mind. It injects a renewed sense of adventure into the experience of being human.
Routledge eBooks, Sep 23, 2022
Philosophical Transactions of the Royal Society A, Jun 19, 2023
We show how distinct terminally disposed self-organizing processes can be linked together so that... more We show how distinct terminally disposed self-organizing processes can be linked together so that they collectively suppress each other's self-undermining tendency despite also potentiating it to occur in a restricted way. In this way, each process produces the supportive and limiting boundary conditions for the other. The production of boundary conditions requires dynamical processes that decrease local entropy and increase local constraints. Only the far-from-equilibrium dissipative dynamics of self-organized processes produce these effects. When two such complementary self-organizing processes are linked by a shared substrate—the waste product of one that is the necessary ingredient for the other—the co-dependent structure that results develops toward a self-sustaining target state that avoids the termination of the whole, and any of its component processes. The result is a perfectly naturalized model of teleological causation that both escapes the threat of backward influences and does not reduce teleology to selection, chemistry or chance. This article is part of the theme issue ‘Thermodynamics 2.0: Bridging the natural and social sciences (Part 1)’.
Experimental Brain Research, Dec 1, 1993
W.W. Norton eBooks, 1997
This revolutionary book provides fresh answers to long-standing questions of human origins and co... more This revolutionary book provides fresh answers to long-standing questions of human origins and consciousness. Drawing on his breakthrough research in comparative neuroscience, Terrence Deacon offers a wealth of insights into the significance of symbolic thinking: from the co-evolutionary exchange between language and brains over two million years of hominid evolution to the ethical repercussions that followed man's newfound access to other people's thoughts and emotions. Informing these insights is a new understanding of how Darwinian processes underlie the brain's development and function as well as its evolution. In contrast to much contemporary neuroscience that treats the brain as no more or less than a computer, Deacon provides a new clarity of vision into the mechanism of mind. It injects a renewed sense of adventure into the experience of being human.
Page 106. CHAPTER Beyond Piaget's Phenocopy: The Baby in the Lamarckian Bath Terrence W.... more Page 106. CHAPTER Beyond Piaget's Phenocopy: The Baby in the Lamarckian Bath Terrence W. Deacon University of California, Berkeley I think that all structures are constructed and that the fundamental fea-ture is the course ...
BioSystems, Dec 1, 2022
This paper describes an evolutionary process likely involved in hierarchic transitions in biologi... more This paper describes an evolutionary process likely involved in hierarchic transitions in biological evolution at many levels, from genetics to social organization. It is related to the evolutionary process described as contingent neutral evolution (CNE). It involves a sequence of stages initiated by the spontaneous appearance of functional redundancy. This redundancy can be the result of gene duplication, symbiosis, cell-cell interactions, environmental supports, etc. The availability of redundant sources of biological functionality relaxes purifying selection and allows degenerative changes to accumulate in one or more of the duplicates, potentially degrading or otherwise fractionating its function. This degeneration will be effectively neutral so long as another maintains functional integrity. Sexual recombination can potentially sample different combinations of these sub functional alternatives, with the result that favorable synergistic interactions between independently degenerate duplicates will have a non-negligible probability of being uncovered. The expression of such a synergistic combinatorial effect will result in the irreversible degradation of any remaining autonomous functionality, thereby initiating selection to prevent breakup of co-dependency. This becomes relevant to the evolution of hierarchic transitions when two or more organisms reciprocally duplicate functions that each other requires. If the resulting relaxation of selection reliably persists for an extended evolutionary period it will tend to produce complementary degenerative effects in each organism, leading to their irreversible codependency and purifying selection to avoid loss of integrity of their higher order functional unity. This provides a partial inversion of Darwinian logic that explains how the potential costs of the loss of organism autonomy can be mitigated, enabling the incremental transition to a synergistic higher order unit of evolution. This work was partially supported by grants from Human Energy <humanenergy.io> and from the Boundaries of Humanity < boundariesofhumanity.stanford.edu >.
Oxford University Press eBooks, Jun 21, 2018
Towards a general theory of evolution argues that defining natural selection in terms of “blind v... more Towards a general theory of evolution argues that defining natural selection in terms of “blind variation and selective retention”— as in A-life and replicator selection—ignores the fact that what varies is necessarily part of a far-from-equilibrium physical system that requires physical work to be produced. But natural selection theory is agnostic about the physical-chemical mechanisms underlying the maintenance, repair, and reproduction of organism structures and functions. A more general theory of evolution is proposed that includes an account of a type of process able to reconstitute the organization of the physical system capable of producing that process if damaged.
The 86th Annual Meeting of the American Association of Physical Anthropologists, New Orleans, 2017
The MIT Press eBooks, 2003
Behavioral and Brain Sciences, 2019
We agree with Brette's assessment that the coding metaphor has become more problematic than h... more We agree with Brette's assessment that the coding metaphor has become more problematic than helpful for theories of brain and cognitive functioning. In an effort to aid in constructing an alternative, we argue that joining the insights from the dynamical systems approach with the semiotic framework of C. S. Peirce can provide a fruitful perspective.
The relation of symbolic cognition to embodied and situated bodily dynamics remains one of the ha... more The relation of symbolic cognition to embodied and situated bodily dynamics remains one of the hardest problems in the contemporary cognitive sciences. In this paper we show that one of the possible factors contributing to this difficulty is the way the problem is posed. Basing on the theoretical frameworks of cognitive semiotics, ecological psychology and dynamical systems we point to an alternative way of formulating the problem and show how it suggests possible novel solutions. We illustrate the usefulness of this theoretical change in the domain of language development and draw conclusions for computational models of the emergence of symbols in natural cognition and communication as well as in artificial systems.
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Papers by Terrence Deacon