>I'm not quite sure how to define or distinguish the concept of "complexity"
>from "organization." Is semantic closure the definitive difference? If so,
>it seems inseparable from ideas of awareness & experience as we have been
>discussing them. (I recognize that these alternative terms invoke more
>connotations but is "semantic closure" really more informative?).
Terminology is a curse of theoretical studies! I don't say that
"semantic closure" is the best term (I already try using other words,
e.g., "existential closure"), but it seems better than
awareness and experience. Here are my arguments:
1. Closure is a key word which is not explicitely present in
awareness and experience.
2. The word "semantic" indicates that organisms have their own
sign system which may not fit well into human semantics. We can
understand only that part of organism's semantics that fits well
into our semantics. Thus, there is always a semantic "residue".
>Nevertheless, we're basically talking about some kind of awareness or
>experience of self as the root to being an "organism." If, as you say, this
>is analogous to a system "observing itself," not being too anthropomorphic
>about what we mean by observing, then this corresponds with ideas of
>quantum observership (as I argue)...
I agree that quantum systems also have semantic closure. But the
difference is that their semantics is NOT COMMUNICATED because
they are unable to reproduce (except nuclear chain reactions).
>... but perhaps not with all concepts of
>self-organization, because some theories seem to imply that
>self-organization (e.g., dissipative structures) can be adequately
>described as a purely mechanical (syntactical) system, do they not?
Dissipative structures also have semantic closure. And their patterns
are as discrete as quantum states. They can even "reproduce" by
spreading in space. Actually, elementary particles can be viewed
as a kind of dissipative structure on "pre-matter".
You point that dissipative structures allow a purely mechanical
explanation. This does not mean that they have no semantics. But
their semantics is very simple and mostly covered by human semantics.
Thus the "semantic residue" is negligibly small. Pattee wrote
about complimentary models: some simple systems allow both a
mechanistic and semiotic description.
>Now, from my as yet very limited reading of Rosen, he might argue that
>this, if accepted as the definition, cannot be thought of merely in terms
>of syntatical encoding (DNA, etc.) -- which would always leave a "semantic
>reisdue."
Yes, there is a residue! Although a DNA sequence is a description of
an organism, this description is not semantically closed. Thus, it
requires a specific agent to be interpreted. It is impossible to
achive semantic closure by simple adding of information to the DNA.
Information in its passive (syntactic) form does not have a semantic
closure.
>But back to ecosystems. Ecosystems do not have well defined boundaries.
>Traditional definitions pay homage to the idea that an "area" is associated
>with an ecosystem, just as components are necessary features, but space
>actually plays no part in the definition. The abstract definition of an
>ecosystem (as opposed to completely useless definitions that attempt to be
>spatial and material) is functional -- as a set of relations in "n"
>ecological "dimensions."
This "abstract" definition of an ecosystem is actually a MODEL
that is reasonable for very large (or clearly bounded like a pond)
and homogeneous ecosystems. There are no definitions of real
objects. Any definition refers to a model. For example, the
definition of gas refers to ideal gas. There are many other
ecosystems for which your functional definition would not work.
For example, how can you measure the population density if you
don't know where to measure? Another problem is with successions.
Is it the same ecosystem (like ontogenesis) or is it a replacement
of ecosystems. As far as I know there is no general definition of
an ecosystem that would work in all situations and in all time-
and space scales.
>The residual need for semantic closure seems
>inescapable, and, as you say, can be provided for ecosystems from the
>species level, the semantics of which is then merely elaborated into
>resulting ecosystem patterns. This provides yet another level of semantic
>closure, however, since ecosystems are the ultimate reality in evolution
>theory -- being the all-powerful selective environment. Hence semantic
>closure at the phenotypic level can affect evolution - which is my
>"autevolution" hypothesis.
I did not get this. I think that most ecosystems are "coded" at the
species level, i.e., species semantics expands to the ecosystem level.
I briefly looked through your paper on autoevolution at PCP and got
the impression that by autoevolution you mean self-evolution of a
persistent system (like Gaia) without reproduction and selection. Of
course, the term "evolution" has a very broad meaning and can be easily
applied to Gaia, I would argue that the evolution of Gaia was not
adaptive. Of course, now the fate of Gaia is in human hands. It
has become a part of noosphere (a term of Vernadski and Teilhard de
Chardin). Humans may start reproducing Gaia to other planets.
>Another consequence of using "semantic closure" as the criteria (if I
>understand it correctly) is that we would have to claim that a quantum
>particle is a living organism, wheather it is reproductive or not. I'm
>quite comfortable with this idea, for whatever that's worth, but it means
>removing replication from its priveleged position in the definition of
>life. Replication/reproduction would be seen rather as the means for
>elaborating organisms into more intricate and persistent organisms rather
>than the means for creating life.
I already said that although quantum particles have semantic closure,
they usually don't communicate it (no reproduction). Evolution
without communication is limited by a thermodynamic equilibrium
(each event has its fixed probability). An interesting case is Gaia
which has no external communication, but has very intensive internal
communications. In this case, thermodynamic description is not
relevant. There is no way to estimate probabilities (because
the system is unique and transition processes are too long). I am not
sure that Gaia should be considered alive. It looks more like a
non-living system made of living components. We talk mostly about
living - nonliving dychotomy. But life depends on the level
of hierarchy (e.g., scale), and eventually we may find it useful
to distinguish more categories of life. Some living ssytems have
higher organization at the bottom level, other systems have higher
organizations at the top level.
-Alexei
-------------------------------------------------
Alexei Sharov Research Scientist
Dept. of Entomology, Virginia Tech, Blacksburg, VA 24061
Tel. (540) 231-7316; FAX (540) 231-9131; e-mail sharov@vt.edu
Home page: http://www.gypsymoth.ento.vt.edu/~sharov/alexei.html