Heterotopia

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heterotopia

[‚hed·ə·rō′tō·pē·ə]
(ecology)
An abnormal habitat.
(medicine)
Displacement of an organ or other body part from its natural position.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Heterotopia

 

a change in position and site of development of an organ in the course of individual ontogeny in animals; one of the methods of evolutionary rearrangement of an organism.

Heterotopia is the result either of the migration of cells from one germ layer to another, of the displacement of cells within a given germ layer, or of the secondary displacement of organs. Examples of heterotopia include the displacement of the heart to the thoracic cavity in birds and mammals (near the head in fish and amphibians) and the translocation of the forelegs to the rear in higher vertebrates (in comparison to the thoracic fins offish). The term “heterotopia” was introduced by the German naturalist E. Haeckel in 1874 to designate disturbances of the phylogenetically determined spatial sequence of the stages of ontogeny. It was subsequently shown that heterotopia does not fit into Haeckel’s interpretation of cenogenesis.

REFERENCES

Severtsov, A. N. Morfologicheskie zakonomernosti evoliutsii. Moscow-Leningrad, 1939.
Miiller, F. and E. Haeckel. “Osnovnoi biogeneticheskii zakon.” Izbr. raboty. Moscow-Leningrad, 1940.

E. N. MIRZOIAN

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Following this logic, we could say that heterotopy is the linguistic equivalent of uneven development in the capitalist economy.
But Scott's carnivalized collision of high and low in Alsatia is not an aberration in Jacobean London, and Alsatia is a heterotopy only at the level of representations, since a nearly bankrupt King and court ride on debt and deferring payments.
The process of staminode formation must be seen as the o ngoing interaction of heterochrony and heterotopy. Heterochrony changes the developmental timing and rate of development of the organ, without changing the developmental direction; heterotopy changes the nature of the organs formed, not the timing and rate of morphogenesis (Li & Johnston, 2000).
The distinctions made between bracteopetals and andropetals by Hiepko (1965) and Takhtajan (1991), or the terms "homeosis"or "heterotopy," as the total or partial replacement of one part by another of the same organism (e.g., Sattler, 1988, 1994; Li & Johnston, 2000) explain the same as the molecular terminology, but they are based on a different point of view.
Other causes include heterotopy, the change of structural position, and homeosis, the replacement of a structure by another.
We will also discuss some of the limitations of heterochrony and suggest an integrative approach incorporating heterochrony, homeosis and heterotopy in plant ontogenetic and phylogenetic studies.
Other developmental mechanisms include homeosis, heterotopy, and homology.
Heterotopy in plants usually refers to the formation of an organ at the "wrong place." A typical example might be epiphylly, the formation on angiosperm leaves of inflorescences, shoots, buds, or leaves.
The shifting of these developmental onset positions from their normal place on the stem constitutes heterotopy. The development of these epiphyllous structures may involve other developmental processes as well (for details, see Dickinson, 1978).
Heterotopy also occurs on a smaller scale in plant morphogenesis, as, for instance, in the shifting of the onset position of a floral organ's primordia during flower development.
In a broad sense, heterotopy is the positional displacement or translocation of an organ or structure.
Heterotopy, in contrast, creates a character in a novel position by altering the ontogenetic trajectory.