CL:==
>The only quantifiable aspect of complexity I know of is number
>of parts. In this limited sense segmented organisms (such as
>vertebrates) are decreasing in complexity. Of course complexity
>in every other sense may be increasing; but even so, this apparent
>pattern brings a non-Darwinian implication of finitude to the process.
>
Could you clarify why this would be a "non-Darwinian implication"?
Now to definitions of complexity, unfortunately there are more
than one can shake a stick at :). My preference is descriptive
complexity (roughly related to algorithmic complexity). It is
quantifiable in principle but usually not in practice. Nevertheless
I think it gives a good qualitative measure, good enough to rank
most things in order of increasing complexity.
The McShea article I mentioned uses the notion of "morphological
complexity". This definition considers not only the number of
parts but also the "irregularity of their arrangement". As
McShea writes: "Thus, heterogeneous,elaborate, or patternless
systems are complex." "Homogeneous, redundant, or regular"
systems are, on the other hand, ordered, not complex. Thus
crystal formation is a process of *decreasing* complexity.
This is a point of real confusion. Sometimes one hears talk
of "ordered complexity" which is oxymoronic. Instead, one
should say "organized complexity".
McShea also (rightly IMHO) distinguishes between organization
and complexity. Something can be complex without being organized
(junk heap) and organized without being complex (mouse trap).
Basically, complexity is a structural property independent of
function whereas organization involves the structuring of a
system towards some function. Well, needless to say, biological
systems are typically both complex and organized.
Brian Harper
Applied Mechanics
Ohio State University
214 Boyd Lab
155 W. Woodruff Ave
Columbus, OH 43210
"God forbid that we should give out a dream of
our own imagination for a pattern of the world"
-- Francis Bacon