Phyembryogenesis (from other Greek. Φῦλον - tribe, genus, species and embryogenesis) is an evolutionary change in the course of the individual development of organisms. [one]
Content
History
The term was introduced in 1910 by A.N. Severtsov.
Fundamentals of the Theory
The concept of primary ontogenetic changes in relation to phylogenetic (evolutionary) changes
If the course of ontogenesis did not change, then the descendants would not differ from their ancestors.
Through phyembryogenesis, the course of ontogenesis of both the whole organism and individual organs, tissues and cells can change.
Phylembryogenesis leads to phylogenetic changes in both the adult organism and the intermediate stages of its development.
Ways to
There are several modes (methods) of phylembryogenesis. The most important:
- anabolia (extension of the final stages of development)
- deviation (change in the middle stages)
- archallaxis (change in primary primordia).
Modes of phyembryogenesis differ:
- by time of occurrence
- by the nature of evolutionary transformations
By means of modes, phylembryogenesis can occur both progressive development (by complicating the structure and functions of organisms) and regressive (by simplifying the structure and functions of organisms due to their adaptation to new, less diverse living conditions) (for example, with parasitism).
Literature
- Severtsov A.N., Sobr. op., vol. 3, M. - L., 1945, p. 361-452; t. 5, M. - L., 1949, p. 372–456