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Caenogenesis (also variously spelled cenogenesis, kainogenesis, kenogenesis) is the introduction during embryonic development of characters or structure not present in the earlier evolutionary history of the strain or species, as opposed to palingenesis. [1] [2] Notable examples include the addition of the placenta in mammals.

Caenogenesis constitutes a violation to Ernst Haeckel's biogenetic law and was explained by Haeckel as adaptation to the peculiar conditions of the organism's individual development. Other authorities, such as Wilhelm His, Sr., on the contrary saw embryonic differences as precursors to adult differences.

See also

References

  1. ^ Clark, David L. (1962). "Paedomorphosis, Acceleration, and Caenogenesis in the Evolution of Texas Cretaceous Ammonoids". Evolution. 16 (3): 300–305. doi: 10.2307/2406278. ISSN  0014-3820. JSTOR  2406278.
  2. ^ Blanco, M. J.; Alberch, P. (June 1992). "Caenogenesis, Developmental Variability, and Evolution in the Carpus and Tarsus of the Marbled Newttriturus Marmoratus". Evolution. 46 (3): 677–687. doi: 10.1111/j.1558-5646.1992.tb02075.x. PMID  28568662. S2CID  36555766.

Bibliography

Gould, S.J. 1977. Ontogeny and Phylogeny. Cambridge: Harvard University Press.