BCSSS

International Encyclopedia of Systems and Cybernetics

2nd Edition, as published by Charles François 2004 Presented by the Bertalanffy Center for the Study of Systems Science Vienna for public access.

About

The International Encyclopedia of Systems and Cybernetics was first edited and published by the system scientist Charles François in 1997. The online version that is provided here was based on the 2nd edition in 2004. It was uploaded and gifted to the center by ASC president Michael Lissack in 2019; the BCSSS purchased the rights for the re-publication of this volume in 200?. In 2018, the original editor expressed his wish to pass on the stewardship over the maintenance and further development of the encyclopedia to the Bertalanffy Center. In the future, the BCSSS seeks to further develop the encyclopedia by open collaboration within the systems sciences. Until the center has found and been able to implement an adequate technical solution for this, the static website is made accessible for the benefit of public scholarship and education.

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POLYMORPHISM 1)5)

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The occurence of different basic characters, forms or types in a population.

The concept comes from population genetics, but has a more general scope.

Polymorphism may be transient when the environment acts as a filterand eliminates some variants. It may be permanent if some variety is necessary for a better global adaptation of the population to a fluctuating environment.

According to R. LEVINS: "Polymorphism contributes to the fitness in two distinct ways. If the environment heterogeneity is large compared to the tolerance of the individual (if the environment consists of several discrete niches, in which different phenotypes are optimal, or if it is distributed bimodally about modes which are sufficiently far apart compared to the tolerance), a certain phenotypic heterogeneity is advantageous as a 'mixed strategy' in conditions of temporal fluctuations.

"Regardless of whether this first type of polymorphism is desirable, genetic heterogeneity is necessary for any response to selection. The response to selection is advantageous if the environment is sufficiently strongly autocorrelated" (1961, p.38).

Polymorphism guarantees that at least some individuals in a population will adapt even to strong environmental variations. It corresponds to ASHBY's variety.

The suppression of polymorphism as for example in excessive selection in plants, leading to mono-cultivation, may be risky. Inversely, the existence of polymorphism, for instance in a population of pests, explains the progressive appearance of varieties resistant to chemicals.

Conditions analogous to polymorphism also seem to exist in animal behavior and in human social and cultural life.

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Categories

  • 1) General information
  • 2) Methodology or model
  • 3) Epistemology, ontology and semantics
  • 4) Human sciences
  • 5) Discipline oriented

Publisher

Bertalanffy Center for the Study of Systems Science(2020).

To cite this page, please use the following information:

Bertalanffy Center for the Study of Systems Science (2020). Title of the entry. In Charles François (Ed.), International Encyclopedia of Systems and Cybernetics (2). Retrieved from www.systemspedia.org/[full/url]

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