I have been reading this interchange, and wish to put in my tuppence
worth.
For me complexity is relative to the modelling framework (modelling
language/system, mapping into the object system, modelling goals, etc.).
If you agree on these (i.e. fix them) you can come to objective
agreement on complexity judgements, but complexity, as such, is not a
property of 'reality' as such, but the chosen projection of such (or
formal systems) into a modelling framework. (see my papers
http://bruce.edmonds.name/evolcomp/ and
http://cfpm.org/cpmrep23.html).
This approach means it is *very* important to specify how you wish to
model such ecologies. For example:
* from the point of view of an exterior observer, but with what
modelling language/system and what goal?
* from the point of view of a member of that ecology, again for what
purpose (to survive?)?
* from the point of view of a potential new entrant to the ecology
* etc. etc.
There will NOT be ONE ecological complexity for all aspects.
As I understand it Rosen is not so helpful in making complexity
judgements about ecologies, since it is always possible to model such
ecologies from an infinite number of viewpoints- so by his formulation
they are all equally complex. Don is the person to ask about Rosen's
view on this - it may be that Rosen has reasons why such questions as
the relative complexity of different ecologies is meaningless.
Regards
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Bruce Edmonds,
Centre for Policy Modelling,
Manchester Metropolitan University, Aytoun Bldg.,
Aytoun St., Manchester, M1 3GH. UK.
Tel: +44 161 247 6479 Fax: +44 161 247 6802
http://bruce.edmonds.name