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Scaffolding, Entrenchment, and Combinatorial Modularity

Scaffolding, Entrenchment, and Combinatorial Modularity

W. C. Wimsatt
ECLT New Data - Old theories
May 2014

Insite Project

May 13, 2014

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  1. Scaffolding, Entrenchment, and
    Combinatorial Modularity

    W. C. Wimsatt

    ECLIT Innovation and big data

    May 7, 2014

    View Slide

  2. The Vienna Series in Theoretical Biology

    Developing Scaffolds in

    Evolution, Culture, and

    Edited by Linnda Caporael,

    James R. Griesemer,

    and William C. Wimsatt

    View Slide

  3. Generative entrenchment reflects dependency relations among
    elements in a developing or operating adaptive system. Greater
    entrenchment yields greater conservatism in the evolution of
    parts or activities of the system, but generatively entrenched
    parts can also provide the basis for subsequent adaptive
    radiations of elements that depend upon it.

    Scaffolding is the use or generation of external parts or
    processes to facilitate performance of tasks by the system.
    Niche construction theory and Ecological Engineering are both
    elaborations of this idea.

    These two concepts, entrenchment and scaffolding, are
    important tools in conceptualizing the development and evolution
    of complex adaptive systems. I will apply them to cultural
    evolution, but they are equally central in evolutionary
    developmental biology (e.g., to pleiotropic conservation and to
    chaperone molecules, respectively).

    View Slide

  4. Varieties of Entrenchment

    View Slide

  5. Simple entrenchment

    Here we have an evolving adaptive system with a
    recurring developmental trajectory, a life cycle, and
    differential entrenchment generating different degrees
    of evolutionary conservation. More deeply entrenched
    features are more likely to be preserved and thus to
    acquire further downstream dependent adaptations or
    features which presuppose their presence.

    View Slide

  6. Treat the life cycle as a porous
    spatio-temporal sausage with
    characteristic events in a
    developmental trajectory
    initiating others cycling in and
    out of the target system.

    Earlier events tend to have more
    downstream dependencies than
    later ones, increasing
    evolutionary conservatism.

    Ignoring cycles through the
    environment underestimates
    generative entrenchment inside
    as well as outside the system.
    Differential entrenchment and
    differential conservatism can
    explain and predict account of
    phenotypic evolution without
    using genes.

    Developmental Time
    Early Change Early Change
    Late Change
    J. C. Schank – ©1997/2002
    b c

    View Slide

  7. von Baer’s (1828) Law:

    Earlier stages of diverse
    organisms are more similar
    than later ones. To Darwin,
    this suggested common

    This earlier evolutionary
    conservatism is explained
    by the greater downstream
    dependencies the
    generative entrenchment

    of earlier features.

    View Slide

  8. This idea was significantly elaborated before big
    data, and particularly before genetic data, by
    Rupert Riedl (1975, English translation 1978), but
    since the explosion of genomic data giving
    comparative phylogenetic information and the
    possibility of detailed genomic analysis like those
    of Eric Davidson and Doug Erwin, analyses of
    genetic circuitry of increasing resolution and
    breadth have become possible.

    View Slide

  9. One result of cross phyletic
    comparison is the
    extraction of the kind of
    genomic architecture
    pictured here (Fig. 5.6,
    Davidson 2006, p. 219),
    indicating a kernel
    underlying specification in
    the heart progenitor field.
    He compares the circuitry
    in Drosophila and in
    Vertebrates, and extracts
    elements of the circuitry
    they have in common—
    presumably ancestral to
    both. Note that conserved
    elements are not DNA
    sequences, or even genes,
    but functional roles.

    View Slide

  10. For cultural evolution, developmental structure is even more
    crucial. Biological genes are acquired from a single breeding
    population in a single bolus at the beginning of the life cycle.
    But elements of culture are acquired throughout the life cycle,
    with earlier ones often affecting which later ones are acquired,
    and how they are interpreted and elaborated. They in effect
    confound heredity, development, and selection, making traditional
    age-structured models with this data forbiddingly complex. This
    dependency structure is crucial in skill acquisition. We pass
    through a series of culturally induced breeding populations as
    we grow older, with social structures often keyed (through
    schooling and curricula) to the skills we must acquire. Thus
    cultural evolution is structured through an articulation of
    internal and external structure, an “endogenetics” and
    “exogenetics” (Wimsatt, 2000).

    View Slide

  11. (Language: early onset &
    maturation of receptive,
    transmitting abilities; later
    output a function of other
    behaviors and timing of
    (Calculus: late onset of
    both receptive ability and
    transmitting ability; latter
    may lag behind former)
    (History, Philosophy, other
    “thick” cultural traits:
    cumulative knowledge
    accumulation and ability
    to transmit.)
    (Different reception, transmission
    profiles for different cultural traits)
    Different skills
    have different
    trajectories and
    modes of

    View Slide

  12. Learning of Task Complexes on
    Guanaro Island in the Orinoco Delta

    from S. Shennan, 2002, Genes,
    Memes and Human History, London,
    Thames and Hudson, p. 41

    Shennan also cites (p.39) information
    indicating that the productivity of an
    18-20 year old Ache hunter is only
    about 20% that of a 25-50 year-old,
    indicating the relevance of expertise
    in performance, and why some of
    these tasks should be taught and
    learned over an extended time.

    View Slide

  13. On the structure of genetics vs. other sciences,

    and generative entrenchment:

    “Genetics is a quantitative subject. it deals with ratios, with measurements, and
    with the geometrical relationships of chromosomes. ... [I]t is a mathematically
    formulated subject that is logically complete and self-contained.”

    “We have attempted to treat the subject in a way suggested by these
    considerations—namely as a logical development in which each step depends upon
    the preceding ones. This book should be read from the beginning, like a textbook of
    mathematics or physics, rather than in an arbitrarily chosen order, like a textbook of
    comparative anatomy or natural history.”

    “Genetics also resembles other mathematically developed subjects, in that
    facility in the use and understanding of its principles comes only from using them.
    The problems at the end of each chapter are designed to give this practice. It is
    important that they actually be solved.” (Preface, p. 11)


    --A. H. Sturtevant and G. W. Beadle, An Introduction to Genetics, New York:
    W. B. Saunders, 1939.

    View Slide

  14. Maintenance entrenchment

    The closed causal loop explaining the persistence of entrenched
    elements in life cycles also arises when elements help to maintain
    important features in a persisting adaptive system. They thus
    preserve the system and themselves. These “closed causal loops”
    maintain the entrenched elements within the life trajectory
    without a repeated life cycle. These “system metabolic functions”
    contribute to the operation of stable mature systems or the
    continued development of competence in a given area or set of
    areas through continued use or reuse of a developing capability.
    Thus an ontogeny can generate recurrences and entrenchments
    within it without passing to the next generation. This is
    particularly important in cultural evolution where many systems
    undergo extended development without obvious life-cycles.

    View Slide

  15. Combinatorial Entrenchments

    Combinatorial systems are adaptations of larger systems that
    generate many variations using elements that can be put
    together in multiple ways. These basic elements become
    modules, which can play the same or different functional roles
    in different systems. The combinations provide readily generated
    possible alternatives from which complex structures can be
    assembled to accomplish diverse tasks. Thus language, machine
    parts, amino acids and computer code are such reusable parts.
    These possibilities make the elements increasingly entrenched
    as they come to be used for diverse functions in different
    constructions. This allows rapid evolution—usually in an
    “adaptive radiation”—of the systems containing the
    combinatorial elements as the different possible adaptive
    combinations are exploited.

    View Slide

  16. Overlapping and Embedded Entrenchments

    Some writers complain that cultural change is ambiguous between
    evolution and development, and thus fits neither. This is explicable. A
    complex compositional structure may involve many different-sized and
    hierarchically composed systems reproducing on different time scales.
    This occurs in biological and cultural systems and in hybrids of both.
    Metazoans develop through multiplication and division of cells, so
    entrenchment in cellular processes and reproduction through mitosis is
    embedded in metazoan development. Entrenchments through learning and
    habit occur in individual ontogenies, both in biology and cognition.
    “Innate” factors in cognition (Wimsatt 1986, 2003) assist language
    acquisition (Dove 2012) or other cultural processes in the individual. New
    employees learn their specialized tasks in training to acquire complex
    sequential skills in a corporation. Cycles of repetitive learning entrench
    individual practices and quirks within habits, which are layered, with
    earlier entrenched habits modulated and entrained in later constructions
    employing them.

    View Slide

  17. Evolutionary meta-ontogeniesç

    Overlapping entrenchments of lineages with different life cycles
    and scopes yield hybrid lineages that fail to fit traditional
    categories for evolving systems. They

    1. may show definite ontogenetic features, but

    2. unlike organisms, may not have determinate life cycles or
    determinate ways of reproduction (e.g., business firms),

    3. may evolve (possibly without a populational environment of
    exchange or competition--e.g., ecologies), and

    4. may show substantial horizontal borrowing or lateral
    hereditary transmission compromising the individuality of the
    lineages, and

    5. may be strongly interactive with other like entities—so
    strongly that (with 4) separations seem arbitrary or multiply
    constructable, so that it is problematic to individuate species.

    View Slide

  18. Elements required for

    a theory of cultural evolution

    View Slide

  19. Units:

    1. transmissible elements (TREs): artifacts, practices, ideas which are taught, learned,
    constructed, imitated (note that these include both ideational and material things)

    2. individuals who develop, are socialized and trained over time (in multiple contexts)
    and whose earlier training affects their capabilities, exposure and receptivity

    Built parts of the human cognitive, normative and affective environment that scaffold
    acquisition and performance of knowledge and skills, and coordinates acquisition of
    sequential skills. Some of these can also act as reproducers on their own:

    3. institutions – normative rules or frameworks guiding behavior [like TREs but at
    social/group level] e.g., social norms of behavior, legal codes, certification exams
    and transition rituals (confirmation, bar/bat mitzvah, graduations, marriages)

    4. organizations – self-maintaining groups of individuals self-organized for a purpose
    [like individuals, but at a social/group level] (interest groups, firms, nations,

    5. artifact-structures – physical infrastructure maintained on trans-generational time
    scales providing “public goods”, or toolkits for specialist activities. Government
    bodies are hybrids of all three, and many/most culturally transmitted processes
    involve rich emic (ref Tostevin) interactions with material artifacts.

    View Slide

  20. We grow in a trajectory in which the
    environment is structured by these
    social and cultural entities and we are
    scaffolded in our enculturated

    View Slide

  21. Scaffolding

    Structure-like dynamical interactions with performing individuals that
    are means through which other structures or competencies are
    constructed or acquired by individuals or organizations (Thus the cell
    scaffolds gene replication and expression so fully that one wonders whether the
    relevant reproductive unit is the cell rather than the gene or genome. So also for the
    enculturated socialized human.)

    Relevant scaffolding for individuals: family structure, schools [physical], curricula,
    disciplines, professional societies, church, work-organization, interest-groups,
    governmental units, laws

    Scaffolding for organizations (e.g. business): articles of incorporation, corporate law,
    manufacturers’ organizations, chambers of commerce, distribution networks

    Artifacts: machine tools, clothing, housing, cars, gasoline, computers, seminar tables,

    Infrastructural scaffolding: language, schools, roads, sea, rail and air networks,
    shopping centers, truck farming, gas, water, power, telephone, distribution warehouses
    and networks, public transport, ethernet

    View Slide

  22. Compound scaffolding:

    20 story platforms +

    large stairs (at left) +
    ladder (middle right) +
    cherrypicker (bottom
    right) + hoists (right) +
    pedestrian shielding
    (bottom), all modular,
    adjustable, transportable,
    and easily customized
    (note different treatment
    at top) for different needs.

    CTS tuckpointing,

    Chicago, March 2007

    View Slide

  23. And here is some bio-cultural evolution--a parasitic
    vines scaffolding itself across a 2 lane highway
    (scaffolding cars which scaffold human transportation)
    on a wire (scaffolding telecommunications and power
    distribution), while animal parasites in the background
    (tent caterpillars) construct their reproductive niche,
    webbing branches together as they strips the leaves.

    View Slide

  24. Institutional
    cultural ideas
    and practices
    Individuals construct institutions, their standards,
    and their transmitted contents.
    W. C. Wimsatt 11-23-01
    But scaffolding in culture is much
    richer and more interdependent.
    Consider that construction and
    maintenance of curricula
    presupposes schools, classes,
    textbooks, textbook publishers and
    writers, professional societies of
    specialists who research, develop and
    report on new materials , teacher
    training, and certification procedures.

    View Slide

  25. And for a big industry, like the
    automotive industry, the yellow pages
    reflects the diversity of support roles
    and spinoff occupations

    View Slide

  26. Chicago 2001 Yellow Pages (consumer): Automotive Entries [spinoff scaffolding]

    pp 93-184 out of 2176 at 5 columns/pg.; also ~20 more entries of form, “X”, see “Y”


    page #’s


    Air conditioning sales and service 93-95


    Alarms and security systems




    [.2 col]

    Body repair/paint



    Bumpers, grilles, fenders 106

    [.5 col]

    Buying services






    [.3 col]


    107-127 20






    [1.5 col]



    [.5 col]



    [1.3 col]

    Floor coverings

    [.5 col]

    Inspection stations

    [.2 col]


    [1.5 col]

    Locator service

    [.2 col]

    Machine shop

    [1 col]

    Parts/Supplies [other than dealer]






    [1 col]

    Race cars

    [2.5 col]



    Repair and service


    -repair and service rental

    [.2 col]

    Restoration (antique/lassic)

    [2 col]

    Seat covers, tops, uphostery

    [2 col]


    [1 col]



    [.7 col]

    Upholstery cleaning

    [.3 col]

    Warranty processing

    [.3 col]



    [“C” or manufacturing directory would have much more]

    Does not include:
    Manufacturing, Advertising,
    Distribution networks for cars,
    parts, fuel, Insurance. Licensing,
    State, federal regulation,

    Traffic and State police,
    Interstate and trucking
    regulation, Parking, Suburbs, and
    streets without sidewalks, and
    with cul-du-sacs.

    Highway, Streets and sanitation
    [partial], Drive ins: Motels, Fast
    food, Banking, Shopping malls,
    Suburbs, Movies, Restaurants, ...

    View Slide


    View Slide

  28. Modularity never occurs by itself. It always occurs as
    a part of some larger system that it benefits. It is
    easy when looking at the evolution of organisms to
    focus on the organism and forget its environment. So
    for culture. Cultural or technological evolution is
    always conditioned by the larger systems and
    structures of which they must be a part, whether in
    biology (the genetic code, or proteins, or vertebrae) or
    in technology and culture (a nut-bolt combination,
    computer code, or a list of words).

    View Slide

  29. The development of a combinatorial
    alphabet for the construction of diverse
    complex artifacts was crucial for the
    explosive growth of technology. Modularity
    is the key here, so I will talk about the
    significance and evolution of modularity,
    particularly in technology.

    View Slide

  30. Modularity is a recurrent theme in

    evolved objects and systems.

    Why? For living systems that reproduce themselves,
    it is unavoidable: the very act of reproduction

    makes modules or quasi-independent entities.

    Multicellularity and differentiation are modulations

    on this theme. For technology, it seems a natural
    outgrowth of the development of mass production.

    Why again?

    I discuss some of the features of modularity in
    biology and in culture. I then consider how modular
    parts can emerge through a feedback process
    between part and system level interactions using the
    emergence of standardized parts in the evolution of
    mass production as an illustrative case.

    View Slide

  31. Modularity is common in biology, and a topic
    of discussion for several reasons:

    1. It is easier to make a system with lots of similar
    parts because there are fewer part-types to code for.

    1a. Indeed, reproduction makes maximally identical
    parts to start with.

    1b. However, any interesting machine is made of
    differentiated parts (1a ->? 1b = the challenge of
    biological metazoan development!),

    1c. and often uses even similar parts in dissimilar roles.

    (differentiation; “polyfunctional parts”).


    View Slide

  32. Common (especially standardized) elements can become widely used for many
    functions. [If standardized, these can generate strong constraints on structure of
    elements interacting with them ] Consider a nut-bolt pair, with threaded shaft and hole.

    Polyfunctional Nut-Bolt:

    A. Fixed connection:

    1. structural rigid connector [plus lock washer]

    2. shear pin

    3. fixed spacer [with collars or washers]

    B. Connection fixed in 1 dimension, free in another:

    4. allow free rotate (shaft) between fixed clearances

    C. Continuously adjustable connection:

    5. adjust/maintain angle of radially anchored arm [low torque resistance]

    6. adjust travel [screw adjusts length, to clamp as in a vise, or to raise or force apart as in a jack;

    high force, high mechanical advantage]

    7. adjustable contact/carry current

    D. Integral part of larger mechanism:

    8. measuring device [micrometer, w. calibration, ruling]

    9. “rheostat” control.

    E. Complex (multiples):

    10. levelers on legs of supported structure [w. “shoe”] - Adjust in 2 dimensions!

    11. Bind non-steel (lightly compressible) between plates.

    Exercise: Look at a tinkertoy construction kit manual. Classify the different kinds of functions served by the basic
    elements of the set in the different designs. [Contrast local functions with functions in context of the whole machine.]

    W. C. Wimsatt 3-12-03

    View Slide

  33. H. Herkimer, (1952); Engineer’s Illustrated Thesaurus, New York: Chemical Publishing Company.

    View Slide

  34. 2. A system is easier to modify if you can adapt to local
    circumstances by changing one or a few parts without
    systematically changing the whole, which is both harder,
    and is more likely to have deleterious consequences.

    (“quasi-independent” parts; near-decomposability.)

    3. If you have a small number of parts each of which can
    be put together in different ways, you may make a large
    number of different kinds of things with a small
    “alphabet” of parts.

    (“combinatorial” parts, generative “alphabets”)

    So, in summary, modular parts can be polyfunctional (as a
    function of their differentiated roles in a complex system),
    quasi-independent in their modification, and
    combinatorially generative.

    View Slide

  35. Our artifacts show massive modularity, on multiple
    hierarchical scales. This was pivotal to our
    technological explosion.

    It is crucial to the mass distribution, efficiency,
    adaptability, and complexity of our artifacts that
    they are modular. Modularity is also inevitable,
    since we engineer and assemble them out of parts.
    (We don’t grow them!)

    View Slide

  36. Entrenchment can happen rapidly and massively
    when a part or tool or property of a part becomes
    part of a combinatorial algebra for creating an
    ensemble of possible systems. These parts thus
    become standardized, and can serve diverse
    functions in different systems, which increases their
    standardization and fixity. Thus standards for nuts
    and bolts will persist indefinitely, as entrenchment
    compels a continued need for “metric” vs. “English”
    parts and tools, (e.g., for Fiats and MG’s), even
    though their sizes are both now expressed in the
    metric system. The entrenchment of a 2-digit date
    code in software led to the great fears of financial
    catastrophe in the Y2K crisis.

    View Slide

  37. The end?

    View Slide

  38. Genesis of Modularity for Technology

    0. non-interchangeable parts (though often made
    from the same patterns), co-tuned to work
    together on a system-by-system basis (e.g., parts
    for the “Brown Bess” musket used by Redcoats
    during the American revolution)

    1. with higher accuracy, interchangeable parts (only
    within manufacturer*, often only at the population
    level--can you find a fit in that basket relatively
    quickly?)* Springfield Armory, 1828

    [*also “proprietary” parts of specialty manufacturers]

    View Slide

  39. 2. standardized parts (across manufacturers), with
    coordinated setting of standards, which become self
    reinforcing in a “coordination game”. (consider S.A.E.
    standards for nuts and bolts) [Machine tools and
    measurement gauges are crucial here to generate
    sufficient reproducibility, while their adjustable but
    repeatable settings also allow the same machine tools
    to make diverse kinds of parts.] (comment on changes in
    factory organization and labor practices!)

    3. distribution of standardized parts [e.g. hardware,
    electronics, plumbing, equipment] stores. This is an often
    ignored requirement: the right parts must be in the
    right place at the right time, calling for elaboration of
    coordinated transport mechanisms. [like metabolism].
    (Comment on specialized manufacture and diffusion of
    machine tools, and “mechanics” using “Armory practice”.)

    View Slide

  40. 4. parts become more polyfunctional, and
    generatively entrenched.

    4.1 Different varieties of parts arise with specialized
    applications, all modulations of the same basic design, as
    illustrated with threaded fasteners in the next slide.

    4.2 Aspects that are standardized become categorical
    (metric and English threads are incompatible) barring use
    of replacement parts or tools designed for one on the
    other. Now generatively entrenched, they become
    narrowly specialized (and replaceable only wholesale) or
    broadly applied and virtually irreplaceable.

    4.3 With innovations, where one artifact replaces another,
    if standard formats affect compatibility, “backwards
    compatibility” becomes an issue. (Can you still read old file
    formats with your word processor?)

    View Slide

  41. H. Herkimer, (1952); Engineer’s Illustrated Thesaurus, New York: Chemical Publishing Company.

    View Slide

  42. All of the screw threads for the screw
    devices represented in Herkimer are made
    according to common specifications (one of
    several, from different countries, and for
    different applications). An example of this is
    found under “screw thread” in Wikipedia.

    View Slide

  43. Form and pitch!
    UTS thread form and pitch technical specifications are currently controlled by ASME/ANSI industry standards in the United
    ! •! ASME/ANSI B1.1 - 2003 Unified Inch Screw Threads, UN & UNR Thread Form!
    ! •! ASME/ANSI B1.10M - 2004 Unified Miniature Screw Threads!
    ! •! ASME/ANSI B1.15 - 1995 Unified Inch Screw Threads, UNJ Thread Form!

    P = 1 / TeethPerInch

    H = 0.866025 * P

    H1 = 0.541266 * P

    d1 = d + 1.082532 * P

    d2 = d + 0.433013 * P

    D = d

    D1 = d1

    D2 = d2
    Formulas express all dimensions as
    functions of P and D, generating a
    family of threaded connection sizes

    View Slide

  44. 5. chunking, and hierarchical modularity [not just
    screws, but coils, starter motors, engines, kit houses,

    5.1 leads to modular assembly stages, with sub-
    assemblies constructed in different places than final

    5.2 leads to specialized distribution [autoparts stores,
    etc.], need for directories, and coordination with assembly
    stages (including “just in time” stocking, facilitated by
    computerized inventory control and containerized shipping)

    5.3 subassemblies may be “black boxed” (see below)

    View Slide

  45. View Slide

  46. View Slide

  47. Herkimer’s remarkable text is worthy of special
    note: This “thesaurus” is organized by function
    and within function by kind of mechanism. It
    creates a “design alphabet” of alternatives.
    They aren’t strict functional equivalents, since
    each is specialized to a more particular kind of
    application. And they are types, not particular
    parts. This text also encourages engineers to
    break complex design problems into sub-
    problems (Simon’s “near-decomposability”) and
    to use existing solutions rather than to invent
    yet other variants unless absolutely necessary.

    View Slide

  48. So the engineer can use these to contact
    manufacturers for types of parts, either
    subcontracting the part, or getting further
    information necessary to design the specialized
    variant for themselves. There is often a close linkage
    between industry and theory, with industry
    influencing and scaffolding the education of
    engineers both in college and on the job. (The classic
    text on “Modern Steam Engineering” by Hiscox, was
    distributed (with interleaved glossy catalog pages)

    by the New York Belting and Packing Co.) See also
    Murmann 2003 on interactions between dye industry
    and research universities in Germany in late 19th c.

    View Slide

  49. 6. redesign of non-modular things for modular
    construction (at lower time, cost), often to use
    non-optimal but easily available components. (cf.
    Sears’ kit houses below).

    7. competitive elimination of non-modularized
    and non-standardized designs that are more
    expensive, require more labor and knowledge to
    repair or support. (You can’t order a standard
    replacement window for a Frank Lloyd Wright
    house.) Standardized parts allows for pre-
    manufactured local availability, standardized
    tools, and standardized training for construction
    and repair.

    View Slide

  50. Sears Kit houses, marketed from
    1908 to about 1934 in increasing
    variety and sophistication. With
    30,000 parts in the average kit,
    coming in two or more boxcars
    to a railroad siding near you.
    Labor saving (precut and labeled),
    and standardized, with choices of
    construction quality level (a high
    level decision that changed
    hundreds to thousands of parts-
    specifications), mode of heating
    and lighting, indoor plumbing, and
    of course the furnishings from
    your Sears catalogue. Choices
    with generative classifications like
    these saved hundreds or
    thousands of detailed decisions.

    View Slide

  51. Steam vs. hot water
    heat, anyone?

    View Slide

  52. And a coordinated set
    of light fixtures to fit
    your trim style.
    (These are electric
    lights--you can install
    gas instead, and buy
    similar fixtures for
    either gas or
    electricity in your
    Sears catalogue.)

    View Slide

  53. Choose your
    door styles and
    then door
    attic to basement
    and inside to
    outside. These
    housing designs
    are modular all
    the way through.

    View Slide

  54. 8. black boxing: removing ability to disassemble,

    8.1 in distribution of parts (e.g., “accessory

    8.2 in manufacturing, generating subsystems that
    are designed to be replaced whole, or

    8.3 in forgoing expertise for dealing with the
    disassembled black box.

    8.4 See lost skills—e.g., blacksmithing, component
    repair (Can you get a radio fixed or a car
    generator rebuilt, as I did in Canada (not in US) on
    a Saturday afternoon in 1970)?

    View Slide

  55. 9. exploitation of combinatorial possibilities of
    modular design, e.g., alternatives in materials,
    selling of decorative doorframes, mantlepieces,
    bookcases, cabinetry complexes to be installed
    in Sears house. [This requires design so that
    the add-on accessories are consistent with each
    other—both stylistically and mechanically].

    Or look at the number of specialized
    accessories for computers or cars.

    View Slide

  56. Indeed, even
    or repair is
    modular, and
    for different

    View Slide

  57. NOTE that modularizing something into parts
    can disentrench their organization (by making it
    more readily disassembled and rearranged) at
    the same time as they entrench the components
    as a common alphabet.

    10. design of accessories for modularized things.
    [if adapted to specialized devices -->

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  58. 11. Training for modularity: autotelic folk
    models: tinkertoy, lincoln log, erector set,
    lego, etc. teach engineering compositional
    paradigm and polyfunctionality: use same
    parts to make different kinds of things,
    using the parts in (sometimes ingeniously)
    different ways--and each have their own
    standardized parts!

    (Buy your kid a tinkertoy set for
    Christmas, and play with it!)

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  59. View Slide

  60. For kids only? In his book The Box, about
    the development of containerized
    transport, Marc Levinson describes how
    Matson shipping engineer Les Harlander
    prototyped and tested the arrangement
    for a problematic lifting spreader on the
    shipside crane on his son’s Erector Set
    over Christmas, 1957.

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  61. The end!!

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  62. With these, we get one important
    concept for free: Note that if you are
    forced to return to the same or nearly
    the same place in successive generations,
    you then automatically have something
    that will be regarded as a “life cycle.”

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  63. Here is another example, for electronic
    circuit components. The set mimics the multi-
    layer architecture of an IC chip. Notice how
    it is advertised.

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  64. Bristol Pegasus

    Engine 1938 with
    accessories, which
    increase in number
    and complexity
    with performance:

    some scaffold
    engine performance

    (oil pump, air

    some others
    scaffold activities of
    pilot or operation
    of the airplane
    hydraulic pump)

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  65. View Slide

  66. View Slide

  67. 6. redesign of non-modular things for modular
    construction (at lower time, cost), often to use
    non-optimal but easily available components. (cf.
    Sears’ kit houses below).

    7. competitive elimination of non-modularized
    and non-standardized designs that are more
    expensive, require more labor and knowledge to
    repair or support. (You can’t order a standard
    replacement window for a Frank Lloyd Wright
    house.) Standardized parts allows for pre-
    manufactured local availability, standardized
    tools, and standardized training for construction
    and repair.

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  68. Of course
    this happens
    in nature
    which is
    scaffold and

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  69. And the same ambiguity
    exists for technology. After
    all, the construction and
    maintenance of large
    buildings makes a niche for
    workers doing the tuck-
    pointing, contractors
    specializing in assembling
    the scaffolding, operators
    and manufacturers of
    mechanical “cherry-
    pickers” and the reusable
    and readily adaptable
    scaffolding parts.

    CTS tuckpointing,

    Chicago, March 2007

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  70. View Slide

  71. Darwin’s Principles Embodied—

    Evolution and Entrenchment of Generative Structures:

    Any evolving system must meet what Lewontin (1970) has called
    “Darwin’s principles”; they must:

    (1) have descendants which differ from one another in
    their properties (variation),

    (2) some of which are heritable (heritable variation), and

    (3) have varying causal tendencies to have descendants

    (heritable variation in fitness).

    These three principles are core requirements for evolution. Any
    population of entities meeting all three of these conditions will undergo
    an evolutionary process, and nothing which fail to meet all of them can do
    so. Think of them as logical or conceptual conditions for an evolutionary
    process: they key into the fundamental requirements of evolution by
    natural selection.

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  72. Two other very general conditions reflect development’s central role in the
    evolutionary process. No interesting evolutionary process (physical or
    conceptual) fails to meet them. Evolving entities must also be:

    (4) structures generated over time so they have a
    developmental history (generativity), and have

    (5) parts which have larger or more pervasive effects
    than others in that production (differential entrenchment).

    Then different elements in the structures characteristically have downstream
    effects of different magnitudes. The generative entrenchment (GE) of an
    element is the magnitude of those effects in that generation or life cycle.
    Elements with larger degrees of GE are generators. This is a degree property.
    The GE of an element in an evolutionary unit has deep consequences for its
    evolutionary fate, character, rate of change, and that of systems impinging on it.

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