Evolution of Complex Systems

1. Evolution of Complex Systems Lecture 11: Advanced concepts Peter Andras / Bruce Charlton peter.andras@ncl.ac.uk bruce.charlton@ncl.ac.uk

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

3. Continuation distributions • E.g., human language • Formalism:

4. Random events • Example: random spikes / spontaneous spikes

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

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

7. 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

8. Simplification of languages – 1 • E.g., • Neurons: graded potentials / spikes • Brain: diverse cortex structure / crystalline cortex structure • Language: rich culture / simple culture

9. Simplification of languages – 2 • Smaller symbol sets

10. Expansion of the language • Longer possible sequences • Increased informational contents – better description of the system / environment

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

12. 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

13. Structure of communications • Grammar in human language • Courtship behaviour rules in animals • Structuring the brain

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

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

16. Expansion by specialist communications • The possible continuation communications are reduced in number • P(x|R(x)) increases • Longer referential sequences are possible  expansion of the communication system

17. 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

18. Institutions – 1 • E.g., • Courtship, marriage • Parliament, cerebellum, Golgi organelle

19. Institutions – 2 • Institution: large set of coherent rules imposing structure • The structural rules imply the constitution of a subsystem of the communication system

20. Institutions – 3 • By inducing a subsystem, institutions lead to the expansion of the communication system

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

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

23. Language code – 1 • E.g., legal system: • legal / illegal • common / statute / commercial / penal • Multilevel set of questions with few possible answers that classify communications

24. 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

25. 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

26. Environment of systems • Environment: infinitely complex • System: communications about itself – complementary model of the environment

27. 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

28. 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 system’s description of the environment allows good predictions about the environment to reproduce and expand the system  predictive sustainability

29. 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

30. 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

31. 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

32. 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

33. 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)

34. 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

35. 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

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

37. 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

38. Interpenetration and emergence of systems • Systems interpenetrating  modifying each other’s 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

39. Examples • Biology and mathematics  theoretical biology • Neuroscience and pharmacology  neuro-pharmacology • Media and hospitals  health care PR

40. Evolution of systems – 1 • Systems recreate and expand themselves • They interact with other systems • Changing their rules • Changing their boundaries • Changing their identity

41. 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

42. 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

43. 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)

44. Evolution of systems – Summary • Systems recreate, expand and change • New systems and subsystems emerge • Systems compete and some are selected under environmental selection pressures

45. Summary – 1 • Length of communication references • Simplification and expansion • Structures, institutes and sub-systems • Professional languages and binary code • Predictive sustainability and selection

46. Summary – 2 • Changing system boundaries • Interpenetration of systems • Double contingency and the emergence of systems • Evolution of systems

47. Q&A – 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 ?

48. Q&A – 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 ?

49. Q&A – 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 system’s ability to reproduce and expand in an environment depends on the system’s predictive sustainability ? 10. Is it true that selection pressures favour systems with richer symbol sets ?

50. Q&A – 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 ?