Polygenesis


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Polygenesis

 

(also polyphylesis), the conjectured origin of a systematic group of organisms (taxon) from two or more ancestral groups as a result of convergence. Some botanists believe, for example, that dicotyledonous and monocotyledonous plants originated from different ancestors and represent two parallel lines of flowering plants, the resemblance between them being the result of convergence.

It has been conjectured that different groups of animals have a polygenetic origin. It is likely, for example, that large groups of mammals originated from different groups of reptiles, the Therapsida. Such cases, sometimes said to be paragenetic, are not polygenetic, since there was only one basic original group. Therefore, if a group of organisms once considered monogenetic has elements of different origins, it should be divided into as many taxonomic entities as necessary to represent the separate and differently related groups constituting it. “There is no place in the phylogenetic system for polygenetic groups. Polygenesis is merely an expression of the imperfection of our classification” (I. I. Shmal’gauzen, Problemy darvinizma, Leningrad, 1969, p. 400).

Particularly unacceptable are artificial taxa for modern evolutionary systematics, one of the main principles of which is the classification of organisms according to the informational content of their genetic program. The taxa of evolutionary systematics can only be monogenetic.

REFERENCE

Mayr, E. Printsipy zoologicheskoi sistematiki. Moscow, 1971. (Translated from English.)

A. L. TAKHTADZHIAN

References in periodicals archive ?
Nevertheless, this work provides evidence that soil gravels, when composed of resistant materials, can preserve their relict features and thus provide information on soil polygenesis that analyses of bulk soil or fine fractions are unable to yield.
White Southern Christians viewed polygenesis as a direct threat to the orthodox interpretation of the creation account in Genesis, and part of a broader attack on a conservative and religious worldview.
And attendant to such claims, Kidd points out, were ideas about monogenesis and polygenesis, and he deftly shows how these arguments impacted nineteenth century discussions about slavery and abolitionism (particularly in the United States), for example, and about the contested claims of Jesus' "race" and "ethnicity.
For example, Sandor Gilman draws radical conclusions from half a sentence in Deronda: 'And one man differs from another, as we all differ from the Bosjesman', (2) claiming that this assumes 'a polygenetic view of race', (3) polygenesis being the belief that races have evolved from more than one set of ancestors so that they are seen as belonging to different lineages.
Gilman (1985) argues that the various vivisections performed on these women were ideologically linked to arguments for polygenesis.
The only dissenters he introduces are religious Southerners who disliked ethnology's racial polygenesis implications and instead rationalized slavery using the Bible.
On the other hand, polygenesis maintains that each creole has its own roots depending on its location and the dominant (colonial) language that was present.
Tejedor Salguero ML, Mendoza CJ, Rodriguez AR, Caldas EF (1985) Polygenesis on deeply weathered Pliocene basalt, Gomera (Canary Islands): from ferrallitization to salinization.
There also existed a scientific literature of American polygenesis that argued that the races were separate species.
Geeraerts names this process Semantic polygenesis, and relates it to the third effect of prototypicality.
This paleosol has a high degree of polygenesis and develops on forested land under warm and humid climate.
A micromorphological comparison of the horizons (Reuter 1964b) proved that the obvious polygenesis can certainly not be a transformation of BrownEarth into Lessive as some other authors have assumed: in the argillic illuvial horizon the clay and silt particles are 90% strongly dispersed.