SENSORY AND MOTOR SYSTEMS: REFLEXES D. C. Mikulecky Professor of Physiology.
IF THE WHOLE WORLD IS COMPLEX, WHY BOTHER? D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY VIRGINIA...
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Transcript of IF THE WHOLE WORLD IS COMPLEX, WHY BOTHER? D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY VIRGINIA...
IF THE WHOLE WORLD IS COMPLEX, WHY BOTHER?
D. C. MIKULECKYPROFESSOR OF PHYSIOLOGY
VIRGINIA COMMONWEALTH UNIVERSITY
http://views.vcu.edu/~mikuleck/
WHAT I HOPE TO ACCOMPLISH
PROVIDE A UNIQUE, WORKABLE CONCEPT OF COMPLEXITY MAKE A CLEAR DISTICTION BETWEEN THE REAL WORLD
AND THOSE FORMAL THINGS WE DO TO TRY TO MODEL IT SHOW HOW THE FORMAL DESCRIPTION OF THE REAL
WORLD REDUCES IT TO SIMPLE MECHANISMS PROVIDE EXAMPLES OF BOTH MECHANISTIC AND
RELATIONAL MODELS OF THE WORLD USE THE DEFINITION OF ORGANISM TO ILLUSTRATE WHAT
CAN BE DONE BY STEPPING OUT OF THE TRADITIONAL FRAMEWORK
CAN WE DEFINE COMPLEXITY?
Complexity is the property of a real world system that is manifest in the inability of any one formalism being adequate to capture all its properties. It requires that we find distinctly different ways of interacting with systems. Distinctly different in
the sense that when we make successful models, the formal systems needed to describe each distinct aspect are NOT
derivable from each other
COMPLEXITY VS COMPLICATION
Von NEUMAN THOUGHT THAT A CRITICAL LEVEL OF “SYSTEM SIZE” WOULD “TRIGGER” THE ONSET OF “COMPLEXITY” (REALLY COMPLICATION)
COMPLEXITY IS MORE A FUNCTION OF SYSTEM QUALITIES RATHER THAN SIZE
COMPLEXITY RESULTS FROM BIFURCATIONS -NOT IN THE DYNAMICS, BUT IN THE DESCRIPTION!
THUS COMPLEX SYSTEMS REQUIRE THAT THEY BE ENCODED INTO MORE THAN ONE FORMAL SYSTEM IN ORDER TO BE MORE COMPLETELY UNDERSTOOD
NATURAL VS FORMAL SYSTEMS
THE REAL WORLD IS COMPLEX WE HAVE TREATED IT FORMALLY AS IF IT
WERE SIMPLE THE RESULT IS THE “DISCOVERY” OF
COMPLEXITY, EMERGENCE,ETC. THE IDEA IS BEST SEEN USING THE
MODELING RELATION
THE MODELING RELATION: THE ESSENCE OF SCIENCE
ALLOWS US TO ASSIGN MEANING TO THE WORLD AROUND US
A “MODEL” OF OUR THINKING PROCESS CAUSALITY IN THE NATURAL SYSTEM IS DEALT
WITH THROUGH IMPLICATION IN A FORMAL SYSTEM
THERE IS AN ENCODING OF THE NATURAL SYSTEM INTO THE FORMAL SYSTEM AND A DECODING BACK
WHEN IT ALL HANGS TOGETHER WE HAVE A MODEL
THE MODELING RELATION: A MODEL OF HOW WE MAKE MODELS
NATURAL SYSTEM
FORMAL SYSTEM
NATURAL SYSTEM
FORMAL SYSTEM
ENCODING
DECODING
CAUSALEVENT
IMPLICATION
WE HAVE A USEFUL MODEL WHEN
ARE SATISFACTORY WAYS OF “UNDERSTANDING”THE CHANGE IN THE WORLD “OUT THERE”
THE MODELING RELATION: A MODEL OF HOW WE MAKE MODELS
NATURAL SYSTEM
FORMAL SYSTEM
NATURAL SYSTEM
FORMAL SYSTEM
ENCODING
DECODING
CAUSALEVENT
MANIPULATION
WHAT “TRADITIONAL SCIENCE” DID TO THE MODELING RELATION
NATURAL SYSTEM
FORMAL SYSTEM
NATURAL SYSTEM
FORMAL SYSTEM
CAUSALEVENT
MANIPULATION
WHAT “TRADITIONAL SCIENCE” DID TO THE MODELING RELATION
NATURAL SYSTEM
FORMAL SYSTEM
NATURAL SYSTEM
FORMAL SYSTEM
MANIPULATION
MORE ON THE MODELING RELATION
THE FORMAL SYSTEM DOES NOT INCLUDE INFORMATION ABOUT ENCODING AND/OR DECODING
THEREFORE MODELING WILL ALWAYS BE AN ART
ONLY IN THE NEWTONIAN PARADIGM DOES THE FORMAL SYSTEM BECOME THE NATURAL SYSTEM (ENCODING AND DECODING ARE AUTOMATIC) AND ALL THAT IS LEFT TO DO IS TO MEASURE THINGS
SCIENCE REDUCED THE WORLD TO
SIMPLE MECHANISMS
THE USUAL SCIENTIFIC PICTURE OF REALITY IS A MECHANISM
DEFICIENT IN CAUSAL RELATIONS FRAGMENTABLE TO ATOMS AND
MOLECULES NOT “GENERIC” BUT TREATED AS IF
THEY WERE
COMPLEXITY
REQUIRES A CIRCLE OF IDEAS AND METHODS THAT DEPART RADICALLY FROM THOSE TAKEN AS AXIOMATIC FOR THE PAST 300 YEARS
OUR CURRENT SYSTEMS THEORY, INCLUDING ALL THAT IS TAKEN FROM PHYSICS OR PHYSICAL SCIENCE, DEALS EXCLUSIVELY WITH SIMPLE SYSTEMS OR MECHANISMS
COMPLEX AND SIMPLE SYSTEMS ARE DISJOINT CATEGORIES
COMPLEX SYSTEMS VS SIMPLE MECHANISMS
COMPLEX NO LARGEST MODEL WHOLE MORE THAN SUM
OF PARTS CAUSAL RELATIONS RICH
AND INTERTWINED GENERIC ANALYTIC SYNTHETIC NON-FRAGMENTABLE NON-COMPUTABLE REAL WORLD
SIMPLE LARGEST MODEL WHOLE IS SUM OF PARTS
CAUSAL RELATIONS DISTINCT
N0N-GENERIC ANALYTIC = SYNTHETIC FRAGMENTABLE COMPUTABLE FORMAL SYSTEM
GENERICITY AND SURROGACY
GENERIC PROPERTIES ARE THOSE POSSESED BY ALL THE MEMBERS OF A CLASS (AS OPPOSED TO SPECIAL PROPERTIES WHICH DISTINGUISH THE MEMBERS OF A CLASS)
SURROGACY IS THE ABILITY TO EXTRAPOLATE ONE’S MEASUREMENTS ON A FEW INDIVIDUALS TO THE GROUP
COMPLEXITY AND EMERGENCE
THE GENERIC ASPECT OF REAL SYSTEMS IS THAT THEY ARE ALL COMPLEX
THIS COMPLEXITY WORKS AGAINST SURROGACY AND LEADS TO THE NOTION OF EMERGENCE
WHY IS ORGANIZATION SPECIAL? BEYOND MERE ATOMS AND MOLECULES
IS THE WHOLE MORE THAN THE SUM OF ITS PARTS?
IF IT IS THERE IS SOMETHING THAT IS LOST WHEN WE BREAK IT DOWN TO ATOMS AND MOLECULES
THAT “SOMETHING” MUST EXIST
WHAT IS ORGANIZATION?
DICTIONARY DEFINITION:
NOUN:
1. THE ACT OR PROCESS OF BEING ORGANIZED
2.THE CONDITION OR MANNER OF BEING ORGANIZED
(ALSO ASSOCIATION OR SOCIETY AND ITS PERSONNEL)
TO ORGANIZE
DICTIONARY DEFINITION:
VERB:
1. TO CAUSE OR DEVELOP AN ORGANIC STRUCTURE
2. TO ARRANGE OR FORM INTO A COHERENT UNITYOR FUNCTIONING WHOLE, TO INTEGRATE
3. TO ARRANGE ELEMENTS INTO A WHOLE OF INTERDEPENDENT PARTS
NOUN OR VERB OR ADJECTIVE?
AN ORGANIZED DESK AN ORGANIZED CORPORATION AN ORGANIZED AUTOMOBILE AN ORGANIZED FROG AN ORGANIZED ECOSYSTEM
WHAT MAKES BIOLOGICAL ORGANIZATION UNIQUE?
SELF-REFERENCE CONTINGENCY PARALLEL DISTRIBUTION MAPPINGS ARE MANY TO MANY RATHER
THAN ONE TO ONE CAUSALITY IS INTERTWINED CATABOLISM AND ANABOLISM ARE
BOTH IMPORTANT MECHANISMS ARE SPECIAL
EVEN IN THE WORLD OF MECHANISMS THERE ARETHE SEEDS OF COMPLEXITY THEORY
THERMODYNAMIC REASONING OPEN SYSTEMS THERMODYNAMICS NETWORK THERMODYNAMICS
THE NATURE OF THERMODYNAMIC REASONING
THERMODYNAMICS IS ABOUT THOSE PROPERTIES OF SYSTEMS WHICH ARE TRUE INDEPENDENT OF MECHANISM
THEREFORE WE CAN NOT LEARN TO DISTINGUISH MECHANISMS BY THERMODYNAMIC REASONING
THERMODYNAMICS OF OPEN SYSTEMS
THE NATURE OF THERMODYNAMIC REASONING
HOW CAN LIFE FIGHT ENTROPY? WHAT ARE THERMODYNAMIC
NETWORKS?
NETWORKS IN NATURE
NATURE EDITORIAL: VOL 234, DECEMBER 17, 1971, pp380-381
“KATCHALSKY AND HIS COLLEAGUES SHOW, WITH EXAMPLES FROM MEMBRANE SYSTEMS, HOW THE TECHNIQUES DEVELOPED IN ENGINEERING SYSTEMS MIGHT BE APPLIED TO THE EXTREMELY HIGHLY CONNECTED AND INHOMOGENEOUS PATTERNS OF FORCES AND FLUXES WHICH ARE CHARACTERISTIC OF CELL BIOLOGY”
MY BOOK:
APPLICATION OF NETWORK THERMODYNAMICS TO PROBLEMS IN BIOMEDICAL ENGINEERING, NYU PRESS, 1993
PREFACE, CONTENTS AND REFERENCES ARE ON MY WEB PAGE
http://views.vcu.edu/~mikuleck/
SOME PUBLISHED NETWORK MODELS OF PHYSIOLOGICAL SYSTEMS
SR (BRIGGS,FEHER) GLOMERULUS (OKEN) ADIPOCYTE GLUCOSE
TRANSPORT AND METABOLISM (MAY)
FROG SKIN MODEL (HUF)
TOAD BLADDER (MINZ)
KIDNEY (FIDELMAN,WATTLINGTON)
FOLATE METABOLISM (GOLDMAN, WHITE)
ATP SYNTHETASE (CAPLAN, PIETROBON, AZZONE)
AN EXAMPLE: SODIUM TRANSPORTING EPITHELIA
CAN BE GROWN IN CULTURE
HAVE A DISTINCT ORGANIZATION WHICH IS NECESSARY AND SUFFICIENT FOR THEIR FUNCTION
UNDERGO A TRANSFORMATION AS THE EPITHELIUM DEVELOPS IN CULTURE
An Epithelial Membrane in Cartoon Form:
A Network Model of Coupled Salt and Volume Flow Through an Epithelium
WHAT IS THE NETWORK THERMODYNAMIC MODEL?
IT CAPTURES ORGANIZATION AS THE NETWORK’S TOPOLOGY
SPHERICAL CELL - SIMPLE TOPOLOGY
FUNCTIONAL EPITHELIUM - SAME CELL DEVELOPS A MORE COMPLICATED TOPOLOGY
LIMITS OF THE NETWORK THERMODYNAMIC MODEL
IT CAN MODEL EITHER CASE, BUT THESE MODELS CONTAIN NO INFORMATION ABOUT WHY ONE TRANSFORMS INTO THE OTHER
IT CAN NOT MODEL THE TRANSITION AS WELL
THE REAL SYSTEM IS COMPLEX
MISSING ASPECTS OF THE TRANSITION TO BE MODELED
CELL SIGNALLING EVENTS
NUCLEAR EVENT
MECHANICAL EVENTS
ONSET OF “EMERGENT” FUNCTION
WHAT HAVE WE LEARNED?
FORMALISMS HAVE LIMITS (GÖDEL) THEREFORE ONE FORMALISM IS NOT
ENOUGH MECHANISTIC FORMALISMS ARE
INADEQUATE FOR CERTAIN PROPERTIES, IN PARTICULAR CHANGES IN ORGANIZATION
WHAT ABOUT OTHER FORMALISMS?
RELATIONAL
OTHERS
THE RELATIONAL APPROACH TO A COMPLEX REALITY
FOCUS ON THE ORGANIZATION DEVELOP A SET OF FUNCTIONAL
COMPONENTS WHICH CAPTURE THAT ORGANIZATION
UTILIZE THE CAUSAL RELATIONS RESULTING FROM ANSWERING “WHY?”
FUNCTIONAL COMPONENTS
MUST POSSESS ENOUGH IDENTITY TO BE CONSIDERED A “THING”
MUST BE ABLE TO ACQUIRE PROPERTIES FROM LARGER SYSTEMS TO WHICH IT MAY BELONG
ITS FORMAL IMAGE IS A MAPPING f: A -----> B
THIS INTRODUCES A NEW KIND OF “DYNAMICS” : RELATIONAL
THE FOUR BECAUSES: WHY A HOUSE?
MATERIAL: THE STUFF IT’S MADE OF EFFICIENT: IT NEEDED A BUILDER FORMAL: THERE WAS A BLUEPRINT FINAL: IT HAS A PURPOSE
METABOLISM/REPAIR SYSTEMS
BASED ON INPUT/OUTPUT REPRESENTATIONS OF SYSTEMS
MORE ABSTRACT ALLOW CAUSALITY TO BE REPRESENTED LEAD TO NEW INFORMATION ARE BASED ON RECOGNITION THAT
BUILDING UP AND TEARING DOWN ARE PART OF THE LIFE PROCESS
THE IMPORTANCE OF CATABOLISM AND ANABOLISM
NO STRUCTURE IS PERMANENT ADAPTABILITY AND CHANGE
INHERENT NEEDS SPECIAL TYPE OF
ORGANIZATION IMPORTANT FOR UNDERSTANDING
EVOLUTION, DEVELOPMENT, AND HEALING
THE RELATIONAL REPRESENTATION
INVOLVES MAPPINGS METABOLISM IS f: A B A REPRESENTS METABOLITES WHICH
CAN ALSO EXCHANGE WITH THE ENVIRONMENT
B REPRESENTS THE RESULTS OF METABOLISM
f IS A MAPPING FROM A TO B
THE CAUSAL RELATIONSHIPS
A IS THE MATERIAL CAUSE OF B (DOTTED ARROW)
f IS THE EFFICIENT CAUSE OF B OTHER COMPONENTS FOR REPAIR
AND REPLICATION COME IN BECAUSE THESE COMPONENTS HAVE A FINITE LIFETIME: CATABOLISM AND ANABOLISM OR “TURNOVER”
f
A B
ROSEN’S RELATIONAL MODEL OF THE ORGANISM
f
A B
ROSEN’S RELATIONAL MODEL OF THE ORGANISM
f
A B
ROSEN’S RELATIONAL MODEL OF THE ORGANISM
ORGANISMS
ARE COMPLEX SYSTEMS
ARE CLOSED TO EFFICIENT CAUSE
ARE AUTOPOIETIC UNITIES
SOME CONSEQUENCES
REDUCTIONISM DID SERIOUS DAMAGE TO THERMODYNAMICS
THERMODYNAMICS IS MORE IN HARMONY WITH TOPOLOGICAL MATHEMATICS THAN IT IS WITH ANALYTICAL MATHEMATICS
THUS TOPOLOGY AND NOT MOLECULAR STATISTICS IS THE FUNDAMENTAL TOOL
EXAMPLES:
CAROTHEODRY’S PROOF OF THE SECOND LAW OF THERMODYNAMICS
THE PROOF OF TELLEGEN’S THEOREM AND THE QUASI-POWER THEOREM
THE PROOF OF “ONSAGER’S” RECIPROCITY THEOREM
RELATIONAL NETWORKS
THROW AWAY THE PHYSICS, KEEP THE ORGANIZATION
DYNAMICS BECOMES A MAPPING BETWEEN SETS
TIME IS IMPLICIT USE FUNCTIONAL COMPONENTS-WHICH DO
NOT MAP INTO ATOMS AND MOLECULES 1:1 AND WHICH ARE IRREDUCABLE
THE NEW VITALISM
LIVING SYSTEMS POSESS A TYPE OF ORGANIZATION WHICH NON-LIVING SYSTEMS DO NOT
THIS BIOLOGICAL ORGANIZATION WILL ALWAYS DEFY FORMALIZATION-IT HAS NON-COMPUTABLE COMPONENTS