Arithmomorphosis

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Arithmomorphosis

 

a type of evolutionary transformation that consists of an increase or decrease in the number of homogeneous or homonomous organs in the process of organic evolution—for example, the variation in the number of rays in the fins of certain fish and the increase in the number of caudal vertebrae in certain vertebrates, such as ichthyosaurs and whales, in their transition to an aquatic form of life.

A. V. IABLOKOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.