cenogenesis

(ˌsiːnəʊˈdʒɛnɪsɪs) n (Biology) a US spelling of caenogenesis

Thesaurus

Noun

cenogenesis - introduction during embryonic development of characters or structure not present in the earlier evolutionary history of the strain or species (such as the addition of the placenta in mammalian evolution)caenogenesis, cainogenesis, kainogenesis, kenogenesisgrowing, growth, ontogenesis, ontogeny, maturation, development - (biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level; "he proposed an indicator of osseous development in children"palingenesis, recapitulation - emergence during embryonic development of various characters or structures that appeared during the evolutionary history of the strain or species

Cenogenesis

the adaptation of an organism occurring in the fetal or larval stage but not retained in the adult form. Examples of cenogénesis are the placenta of mammals (which provides for the respiration, nutrition, and excretion of the fetus), the external gills of the larvae of amphibians, the egg teeth of nestlings (which serve for breaking through the shell), the attachment organs of ascidian larvae, and the tail of the cercaría stage of trema-todes. The term “cenogénesis” was introduced in 1866 by E. Haeckel to designate those features that, in violation of palingenesis (the repetition of distant stages of phylogenesis in the fetal development of an individual organism), make it impossible to trace the sequence of the phylogenetic stages of their precursors during the ontogenesis of modern forms. In other words, cenogenetic features violate the biogenetic law. At the end of the 19th century, the term was used for any change in the course of ontogenesis characteristic of precursors (the German scientists E. Mehnert and F. Keibel). The modern understanding of the term developed as a result of the work of A. N. Severtsov, who retained only the meaning of temporary adaptations or embryo-logical adaptations.

REFERENCES

Lebedkin, S. I. “Biogeneticheskii zakon i teoriia rekapituliatsii.” Za marksistsko-leninskoe estestvoznanie, 1932, [nos.] 3–4.
Severtsov, A. N. Morfologicheskie zakonomernosti evoliutsii. Moscow-Leningrad, 1939.
Ivanova-Kazas, O. M. Sravnilel’naia embriologiia bespozvonochnykh zhivotnykh. Novosibirsk, 1975.
Haeckel, E. Generelle Morphologie der Organismen, vols. 1–2. Berlin, 1866.

A. S. SEVERTSOV

cenogenesis

noun

Synonyms for cenogenesis

noun introduction during embryonic development of characters or structure not present in the earlier evolutionary history of the strain or species (such as the addition of the placenta in mammalian evolution)

Synonyms

caenogenesis
cainogenesis
kainogenesis
kenogenesis

Related Words

growing
growth
ontogenesis
ontogeny
maturation
development

Antonyms

palingenesis
recapitulation