Modularity thinking as a way of managing complexity in developmental biology

Vivette GarcíaUNAM

PhD Student

overview

1. Complexity management as problem solving (PS)

2. Reduction of complexity

3. Management and systems thinking

4. Modularity and management (examples)

5. Management beyond problem solving: modularity thinking is not PS

1. complexity management as problem solving

• Wildness, unruliness, freedom, diversity, and complexity often represent “problems” demanding solutions (Bavington 2002)

• Reduction of complexity is often treated as a way of managing complexity (PS)

2. reduction of complexity

Analytic approaches • Complexity surpasses limits of

cognition: must be reduced• Decomposition and localization

(Bechtel & Richardson 1993)• Heuristics and their biases (Wimsatt

1974,1980) • Cognitive strategies for PS

2. reduction of complexity

Clinical approaches • Complexity of object of study/situation

stands in the way of experimental research

• Experimental /strategic interventions for PS

• The experimental system as reducer of complexity (Rheinberger 1997)

• The social system as reducer of complexity (Thomposn & Trisoglio 1997)

3. management and systems thinking

• Either a system’s complexity is reduced (analytic approaches) or

• A system becomes the reducer of complexity (clinical approaches)

• In both cases, systems thinking enters the picture as part of a managerial solution to a problem

• We owe this to Simon (1962)

3. management and systems thinking

The watchmakers’ parable (argument A)1. Hora and Tempus face the same problem:

constant interruption while assembling watches

2. Hora and Tempus assemble their watches in different ways: the first, hierarchically (in subsystems), the second piece by piece

3. When Hora is interrupted he loses less work than Tempus when he is interrupted

4. Hora prospers -while Tempus fails- because his hierarchical watch design is a solution to the problem of being constantly interrupted

3. management and systems thinking

The watchmakers’ parable (argument B)1. Watches/watchmaking present

complexity2. Hierarchical design allows Hora to

manage (via PS) this complexity3. To have a hierarchical design is to

have the property of being modular4. Modularity is a way of managing

complexity within the PS perspective - or is it?

4. modularity and management

• Even though modularity of developmental/biological systems is linked to Simon’s notion,

• Use of modularity in biology does not render a solution to a problem

• Complexity management by way of modularity does not amount to PS

4. modularity and management

• Is complexity management via modularity a solution to a problem?

• Problem: > complexity of molecular developmental processes, needs reduction

• Solution: decomposition of developmental system and localization of developmental modules?

4. modularity and management

• It is not modules per se, but other types of decompositions, that participate in PS:

• gene territories (e.g., oral ectodermal)• gene networks (e.g., Pax/Six/Eya/Dach)

• Modularity thinking does not provide a general strategy for partitioning systems

4. modularity and management

The notion of modularity is “a simple, butevocative term to describe an array of signaling pathways, protein interactions, gene networks, etc. Some might even argue that because its definitive meaning is unclear it is useful in its vagueness. We can mold it to suit our particular purpose”(Heanue, interview)

5. management beyondproblem solving

Complexity management as PS has been fruitful in many ways:

• Elucidation of cognitive, experimental, and other intervention strategies for dealing with complexity

• Epistemology of discovery expanded from the individual to the social realm

• Characterizations of complexity (Simon’s, Wimsatt’s), and as a property that comes in degrees (reducible)

5. management beyondproblem solving

• Simon-like systems thinking constrains our framework for inquiry into complexity management

• Emphasis on systems thinking has disallowed us to question PS

• Current accounts of complexity management remain within the PS perspective

5. management beyondproblem solving

Take home messages:

• Modularity thinking is a way of managing complexity in biology

• Modularity thinking is not PS

• There is more to complexity management than problem solving

thanks to

Edna Suárez

Griesemer Lab

Peter Taylor (NEWSSC)

Elihu Gerson

UNAM funding