An ecological perspective on constraint and flexibility in biological systems

2 May 2014

Robert Ulanowicz
Chesapeake Biological Laboratory
University of Maryland


The prevailing metaphor for organisms and living systems is that of a machine, albeit sometimes a clunky one beset by noise. Mechanisms and constraints describe most of the behaviors of ontogenetic and biomolecular systems, while noise and flexibility are less apparent and more difficult to apprehend. In ecology, however, flexibility is at times an understatement, and its agency simply cannot be ignored. A more comprehensive metaphor for all living systems appears to be the network of processes. Unfortunately, conventional network analysis addresses only the constraints represented by the links. However, indeterminacies and inefficiencies, as depicted by redundant system pathways, can be quantified as well. Data on ecosystem networks indicate that living systems will persist only if a balance between constraint and flexibility is maintained. Such a dialectic necessarily lies beyond the pale of the conventional metaphysics of "matter moving according to law". It becomes necessary to adopt a new foundation for biology that is process-based and rests on contingency, feedback and memory, each of which violates a corresponding Enlightenment postulate. The way forward to deeper insights into the phenomenon of life appears to lie more with engineering-like phenomenology than with received biological dogma.

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