ORGANISM
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(2) |
| ID | ◀ 2399 ▶ |
| Object type | Discipline oriented, Methodology or model |
A coherent set of structured biological elements able to fulfill processes and functions.
This is the third level of complexity in J.G. MILLER's taxonomy of living systems. Organisms are made of interconnected elements ordered in structures (like organs) and able to carry out interdependent processes, producing a global behavior. MILLER also classifies as organisms colonial living forms and multicellular structures, as for example slime molds, when in their aggregated state. (See “dictyostelium discoideum”).
N. RASHEVSKY gives a more formal definition: “…a system which satisfies a prescribed set of n-ary relations or, in other words, which is described by a set of n-placed predicates that are characterized by specified properties”.
This author adds a caveat: “The choice of the system of such predicates still remains, however, to a large extent, arbitrary” (1967, p.21).
RASHEVSKY states: “A social organism is a set of individuals… A multicellular biological organism is a set of cells and… a unicellular organism may be considered as a set of genes” (Ibid).
An organism may thus be a living system, or a system of living systems.
G. PASK states: “… when we speak of an organism, rather than the chemicals it is made from, we do not mean something described by a control system. An organism is a control system with its own survival as its objective. The basic homeostasis is to preserve itself as an individual… To survive in changeful surroundings an organism must be an adaptive control system” (1961a, p.72).
This concept, first proposed in 1961, is closely related to autopoiesis and autonomy, as can be seen in the following quotation from PASK: “The overall homeostasis, preserving the organism, can be expressed as the conjoint action of many homeostatic systems, each preserving a structure or condition needed for the functioning of the others” (p.73).
It is now commonly admitted, as stated by V. CSANYI, that an organism “… is a more or less autonomous network of components and component producing processes which is replicating in time… As a unity it is also a component of higher organizational levels, like ecosystems or the whole biosphere” (1993, p.264).
This view is close to the organizational closure concept as well as to connectionism.
See also
Auto-genetic system precursor