Anagenesis (redirected from Gradual evolution)

Anagenesis 

(1) In biology, a type of evolutionary process similar to progress. The term was proposed in 1866 by the American paleontologist A. Hyatt to designate the initial stage in the development of large taxonomic groups in the organic world. Characteristic of this stage are the origination of a new type of organization and the flourishing of the group. In 1947 the Austrian biologist B. Rensch used the term “anagenesis” to designate the appearance of new organs and the improvement of structural types in the course of the evolution of large groups of organisms. He contrasted anagenesis with the process of the ramification of the phylogenetic trunk on one level. Anagenesis is characterized by a complexification of organs, by the improvement of their functioning, and by the autonomization of development. Thus, anagenesis is close to aromorphosis.

(2) The process of the regeneration of tissues. (The term is rarely used.)

REFERENCE

Matveev, B. S. “Znachenie vozzrenii A. N. Severtsova na uchenie o progresse i regresse v evoliutsii zhivotnykh dlya sovremennoi biologii.” In Severtsov, A. N. Glavnye napravleniia evoliutsion-nogo protsessa, 3rd ed. Moscow, 1967.

A. V. IABLOKOV