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 ?
During the highly politicized antebellum era, the intellectual efforts of the polygenesis school were aimed at advancing racial apartheid; setting Negroes apart from Whites and defining the so-called Negroes natural position of inferiority in nature.
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.
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.
1998, Polygenesis, Convergence, and Entropy: An Alternative Model of Linguistic Evolution Applied to Semitic Linguistics, Wiesbaden.
Unlike the prevailing polygenesis theories of race that still dominated in Europe, and which postulated irreconcilable racial differences, the American experience seemed to suggest that race was more a dynamic, environmentally determined concept, susceptible to development, notably through racial intermingling (e.
Guenebault (Natural History of the Negro Race, 1837) helped to make polygenesis the dominant scientific position in the 1840s, a time when American intellectuals and scientists had succeeded in discrediting environmentalism.
He rejects the polygenesis argument which underestimates Erasmus's role and which even suggests that he had led some away from Anabaptism.
167), has been refuted, possibly relying on vague generalizations about polygenesis to suffice; otherwise, there is no substantial change in content through the nine editions, and there is little indication of any investigation or knowledge of new theories of folkloric research or study.
Louis Agassiz, the famed Harvard zoologist and convert to polygenesis, was a Swiss immigrant who came to the U.
He discusses ecce homo or slavery and the human variety, classification and the species question, polygenesis and the types of mankind, Darwin in context: science against slavery, and the authority of the sciences of life.
This form of rewriting of the source text in a contemporary context proves the ability of the written epic to be an omnibus genre, not only arising out of polygenesis, but giving rise to literary and performance cultures that traverse boundaries across modes of media.