Publication

[M Lang / S Railsback]

May I humbly point out the recent publication of the following article,
which evolved from a talk I gave at SwarmFest 1999. 

Railsback, S. F. (2001). Concepts from Complex Adaptive Systems as a
framework for individual-based modelling. Ecological Modelling 139:
47-62.

Abstract:
Individual-based models (IBMs) have long been proposed as a key tool for
understanding and predicting ecosystem complexities, yet this approach
has so far contributed relatively little to basic or applied ecology.
Fundamental reasons for the disappointing contribution of IBMs have been
the failure to address critical computer implementation issues and, in
the continuing absence of a theoretical foundation for IBMs, conceptual
flaws in model formulation. At the same time, researchers in the new
field of Complex Adaptive Systems have been studying how complex
behaviors emerge in systems of relatively simple interacting
individuals. Research on Complex Adaptive Systems, while still new and
informal, has identified key concepts for making individual-based
systems realistic and lifelike. I propose that explicit consideration of
the following concepts should make the design of IBMs less ad hoc and
more likely to produce models of value for basic and applied ecology.
(1) Emergence: what behaviors should emerge from the model's mechanistic
representation of key processes vs. being imposed on the model as
empirical relations? (2) Adaptation: given the model's temporal and
spatial scales, what adaptive processes of individuals should be
modeled? What mechanisms do individuals use to adapt in response to what
environmental forces? (3) Fitness: what measures of fitness are
appropriate to use as the basis for modeling decision making? Should
fitness measures change with life history stage? (4) Prediction:
representing fitness-based decision-making realistically can require
modeling how animals consider future consequences of decisions; what are
realistic assumptions about how animals predict decision outcomes? (5)
Computer implementation: what user interfaces are necessary to make the
model, and especially individual behaviors, observable and testable? How
will the model's full design and computer implementation be documented
and tested so results are reproducible and valid?
-- 
address@hidden
Lang, Railsback & Assoc.
250 California Ave., Arcata CA 95521
707-822-0453; Fax 822-1868

Until July 1, 2001: 
        Los Alamos, NM
        505-661-4258


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