Evolution of Complex Systems

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Evolution of Complex Systems

• Lecture 11 Advanced concepts
• Peter Andras / Bruce Charlton
• peter.andras_at_ncl.ac.uk
• bruce.charlton_at_ncl.ac.uk

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Objectives

• Limits of expression of communications
• Simplification and expansion
• Structures and institutes
• Professional languages
• Selection and competition
• Interpenetration of systems
• Evolution

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Continuation distributions

• E.g., human language
• Formalism

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Random events

• Example random spikes / spontaneous spikes

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Meaningless communications

• Not following the rules
• E.g.,
• Random communications
• Zero likelihood communications

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Limited length communications

• How long can be a sequence / pattern of
  referencing communications that does not appear
  as random ?

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Expressivity of a system language

• Richer symbol sets imply shorter reference
  sequences
• Trade-off between symbol set richness and the
  length of referentially interlinked communication
  sequences

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Simplification of languages 1

• E.g.,
• Neurons graded potentials / spikes
• Brain diverse cortex structure / crystalline
  cortex structure
• Language rich culture / simple culture

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Simplification of languages 2

• Smaller symbol sets

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Expansion of the language

• Longer possible sequences
• Increased informational contents better
  description of the system / environment

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Memory and expansion

• Memory facilitates expansion by allowing direct
  reference to earlier communications
• Direct reference increases the likelihood of
  generating continuation communications

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Information subsystem and expansion

• Information subsystem processing of memories,
  generating new memories ? identity definition,
  checking and enforcement communications
• Processing memories combination of memories ?
  simpler referencing of combinations of memories
• ? better self/environment description

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Structure of communications

• Grammar in human language
• Courtship behaviour rules in animals
• Structuring the brain

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Structure

• Restrictions on the communications
• Structure makes sharper the continuation
  distribution, e.g., by eliminating some possible
  continuations

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Specialist communication

• Follows restrictive structural rules
• E.g., science, legal communications

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Expansion by specialist communications

• The possible continuation communications are
  reduced in number
• P(xR(x)) increases
• Longer referential sequences are possible ?
  expansion of the communication system

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Structure and specialisation

• Structure induces simplicity in communications
  and may lead to the emergence of specialist
  communications
• Specialist communications induce expansion of the
  communications system

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Institutions 1

• E.g.,
• Courtship, marriage
• Parliament, cerebellum, Golgi organelle

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Institutions 2

• Institution large set of coherent rules imposing
  structure
• The structural rules imply the constitution of a
  subsystem of the communication system

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Institutions 3

• By inducing a subsystem, institutions lead to the
  expansion of the communication system

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Professional language

• E.g., legal language
• Specialist language in the context of an
  institution system

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Professional institution systems

• Professional language and institution system
• E.g., subsystems of modern society

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Language code 1

• E.g., legal system
• legal / illegal
• common / statute / commercial / penal
• Multilevel set of questions with few possible
  answers that classify communications

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Language code 2

• Professional languages with institution systems
• Multilevel simple answer questions that classify
  the communications along the defining rules of
  the institution system
• Language code ? system identity

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Binary code

• Social sub-systems professional institution
  systems
• Legal / illegal power / no power profit / no
  profit
• Binary code the top level coding that defines
  what communications are part of a communication
  subsystem of the society
• If a communication can be referenced in such
  terms it fits into the subsystem
• There are further levels for inner distinctions

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Environment of systems

• Environment infinitely complex
• System communications about itself
  complementary model of the environment

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System actions and perceptions

• System model of the environment
• Communications reference other communications
  and provide reference for further communications
  ? maintain the system
• Communications lead to changes in the environment
  by changing the behaviour of communication units
• Changes in the environment lead to changes in the
  system communications providing the basis for
  system perceptions

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Predictive sustainability

• The system is reproducible / sustainable if the
  actions of it produce appropriate changes in the
  environment to expand the system
• Also, if perceptions lead to such appropriate
  actions
• In a sense the systems description of the
  environment allows good predictions about the
  environment to reproduce and expand the system ?
  predictive sustainability

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Competing systems

• Systems in the environment
• Each having predictions about the environment
  using their actions and perceptions
• Systems have different level of predictive
  sustainability depending on the environment
• Systems with better predictive sustainability
  attract communication units to produce
  communications that are part of the system easier
  than systems with less predictive sustainability

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Selection of systems

• Systems in an environment
• Selection pressures which system has better
  predictive sustainability in the environment
• Systems with better predictive sustainability are
  selected by the environment

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Simplicity, memory, expansion, selection

• Systems with memory can expand more than systems
  without memory
• Systems that undergo simplification and expansion
  can capture a larger part of the environment
• Longer descriptions make better predictions
• Better predictions make more likely selection by
  environment

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Interacting systems

• Communication units produce communications that
  are part of systems (more than one)
• System communications have effect on
  communication units, these affect the
  communications produced by communication units in
  other communication systems

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The boundary of systems

• Communication units are not part of systems
• Systems are made up by communications between
  communication units
• Dense / rare communication density boundary in
  the sense of referencing
• System communications may also reference
  communications which are not part of the system
  (these are part of other systems)

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Changing system boundaries

• The number of references to communications of
  several systems may change
• In this way the communications may belong more to
  one system than to other systems
• One system may dominate the communications of a
  communication unit of which communications were
  dominated before by another system

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Interpenetrating systems

• Two systems using communications of an
  overlapping set of communication units
• System 1 communications influence communication
  units inducing changes in System 2 it works in
  both ways
• System 2 communications reference sometimes
  System 1 communications
• Such references may follow System 1 referencing
  rules (i.e., continuation distributions)
• New continuation distributions may emerge in
  System 2
• E.g., Politics and education

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Dense communications

• Dense cluster of communications between
  communication units
• Dense cluster in sense of referencing system

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Double contingency and systems

• Referencing to other system communications
• Questioning the existence of the communication
  cluster the system questioning the identity
  of the system (e.g., immune system)
• This leads to the formation of rules and
  sharpening of rules / continuation distributions
• Subsystems as institution systems emerge from a
  grouping of structure rules when the identity of
  the communication cluster is questioned ? double
  contingency

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Interpenetration and emergence of systems

• Systems interpenetrating ? modifying each others
  communication continuation rules
• Communications referring to communications of
  both systems, new communications refer to these
  communications
• New dense referencing cluster may emerge
• Questioning the existence of the new cluster
  leads to the expansion of the cluster and
  formation of the specific rules / continuation
  distributions of the new system ? identity
  definition for the new system

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Examples

• Biology and mathematics ? theoretical biology
• Neuroscience and pharmacology ?
  neuro-pharmacology
• Media and hospitals ? health care PR

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Evolution of systems 1

• Systems recreate and expand themselves
• They interact with other systems
• Changing their rules
• Changing their boundaries
• Changing their identity

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Evolution of systems 2

• Systems develop structures
• The structures may organize into institution
  subsystems by questioning the identity of the
  subsystem
• This may lead to simplifications
• Simplification trigger expansion

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Evolution of systems 3

• At the interface of systems new dense
  communication clusters may emerge
• By questioning the identity (existence) of the
  new clusters new systems emerge

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Evolution of systems 4

• Systems compete for communications between
  communication units
• Systems describe / predict the environment
• Systems with better predictions have better
  predictive sustainability, they are selected
  under environmental selection pressures (they
  more easily reproduce and expand than other
  systems with less predictive sustainability)

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Evolution of systems Summary

• Systems recreate, expand and change
• New systems and subsystems emerge
• Systems compete and some are selected under
  environmental selection pressures

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Summary 1

• Length of communication references
• Simplification and expansion
• Structures, institutes and sub-systems
• Professional languages and binary code
• Predictive sustainability and selection

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Summary 2

• Changing system boundaries
• Interpenetration of systems
• Double contingency and the emergence of systems
• Evolution of systems

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QA 1

• Is it true that simplification of the
  communication symbol set leads to the expansion
  of the communication system ?
• Is it true that structures are restrictions on
  the continuation distributions leading to the
  sharpening of them ?
• Is it true that institutions are rule sets, which
  may organize into sub-systems ?

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QA 2

• 4. Is it true that a professional language is a
  subset of a system language corresponding to an
  institution system ?
• 5. Is it true that the language code defines
  which communications are part of the specialist
  language ?
• 6. Is it true that the political system is a
  professional institution system of the society ?

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QA 3

• 7. Is it true that professional institution
  systems of the society have a binary code ?
• 8. Is it true that system communications can be
  viewed as predictions about the environment ?
• 9. Is it true that a systems ability to
  reproduce and expand in an environment depends on
  the systems predictive sustainability ?
• 10. Is it true that selection pressures favour
  systems with richer symbol sets ?

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QA 4

• 11. Is it true that interpenetration means that
  systems change their boundaries as a result of
  the interaction between the systems ?
• 12. Is it true that new systems always emerge at
  the interface of systems ?
• 13. Is it true that questioning the identity of a
  referential communication cluster leads to the
  formation of the corresponding communication
  system ?