Allomorphosis

allomorphosis [¦al·ō·mȯr′fō·səs]

(evolution)

Allometry in phylogenetic development.

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Allomorphosis 

(allogenesis), a transformation of organisms which is associated with environmental change and in which certain relations with the environment are replaced with other more or less equivalent ones. In allomorphosis there is neither significant organizational complication nor simplification. Allomorphosis is one of the types of adap-togenesis, in which the adaptations to the environment which arise are of a partial character and are not mutually dependent. The adaptation of various passerine species (starlings, orioles, bramblings, buntings, larks, wagtails, birds of the Corvidae family, warblers, tree-crawlers, nuthatches, and titmice) to life under various conditions may serve as an example. (The organization common to passerine birds is preserved, and at the same time a variety of specific adaptations to various conditions appears.) The most clearly allomorphic changes occur in cases of radical changes in conditions, such as transition from water suspension to living on the bottom, from an aquatic to an atmospheric existence, from flight to climbing, from land to subterranean or underwater life, and the like. Allomorphosis leads to an increase in the variety of natural life forms; it is one of the commonest types of evolution of groups. As an independent line of evolutionary progress, allomorphosis was first distinguished by the Soviet biologist I.I. Shmal’gauzen in 1939. Allomorphosis is sometimes regarded as one form of idioadaptation.

REFERENCES

Shmal’gauzen, I. I. Puti i zakonomernosti evoliutsionnogo protsessa. Moscow-Leningrad, 1939.
Sovremennye problemy evoliutsionnoi teorii. Leningrad, 1967.

A. V. IABLOKOV