Heterochrony
Historical document, translated for reference. It reflects medical knowledge of the 1920s–30s and is not medical advice.
Summary
This article defines heterochrony as the occurrence of a phenomenon at an inappropriate time. It explains the term's use in genetics to describe traits appearing in offspring at different ages than in ancestors, and in embryology and oncology to describe the timing of developmental or proliferative events.
Encyclopedia entry (1928–1936)
HETEROCHRONY (from Greek heteros- other and chronos- time), the untimeliness of any phenomenon. This term is often used in the theory of inheritance to denote that a particular hereditary trait is manifested in the offspring not at the same age as in the ancestors (so-called heterochronic inheritance). In embryology and general biology, one speaks of heterochrony in cases where a certain trait appears in the individual's ontogeny earlier or later than in the corresponding phylogenetic forms [a deviation in time from the biogenetic law (see) Haeckel]. One also speaks of heterochrony in oncology (the doctrine of tumors) to denote the untimeliness of the proliferation of embryonic cells in post-embryonic life.
Related articles
Mentioned in
Cite this page
“Heterochrony.” Soviet Medical Encyclopedia. English translation of Bolshaya Meditsinskaya Entsiklopediya, 1st ed. (Moscow, 1928–1936), ed. N. A. Semashko. https://sovietmedicalencyclopedia.pages.dev/article/heterochrony/