Ontogeny
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Ontogeny describes the entire process of an organism's development from fertilization to adulthood, encompassing both physical and psychological changes.[1] It is distinct from phylogeny, which tracks the evolutionary history of a species rather than an individual's lifetime.[2]
Key facts and history
Ernst Haeckel, a strong supporter of Darwinism, first proposed the term ontogeny in the 1860s.[3] The biogenetic law, commonly stated as "ontogeny recapitulates phylogeny," theorizes that embryo stages replay a species' past evolutionary forms.[4] Haeckel argued that new characters added to the end of ontogeny would lengthen development beyond gestation periods.[4] He concluded that embryos only represent embryonic stages of other animals, not adult forms.[4]
Nikolaas Tinbergen's 1963 paper named ontogeny as one of biology's four primary questions.[5] Tinbergen emphasized distinguishing environmental influences from internal changes during development.[6] The word ontogeny derives from Greek roots meaning "a being, individual" and "genesis".[7] In his 1866 publication "Generelle Morphologie der Organismen" ("General Morphology of Organisms"), Haeckel proposed that ontogeny briefly and sometimes incompletely repeats phylogeny.[3]
The relationship between ontogeny and phylogeny was later inverted by marine biologist Walter Garstang, who argued that ontogeny generates phylogeny rather than repeating it.[8]
What the cited sources add
The Embryo Project Encyclopedia notes that Haeckel's biogenetic law was partly based on Darwin's 1859 account of ontogeny in "The Origin of Species"[4] Haeckel hypothesized that truncation of ontogeny caused inconsistencies between embryo similarities across species.[4] For example, pigs and humans look similar as early embryos but diverge as ontogeny progresses.[4] The CARTA source states that in apes and other primates, puberty and reproduction may begin before the juvenile stage ends.[9]
References
- Wikipedia, "Ontogeny" (CC BY-SA 4.0), which cites: Tomasello, "The Normative Turn in Early Moral Development", Human Development, 27 September 2018, p. 248–263 (original not read by us) en.wikipedia.org
- Wikipedia, "Ontogeny" (CC BY-SA 4.0), which cites: "ontogeny biology Britannica", www.britannica.com; Gould, S.J. (1977). Ontogeny and Phylogeny. Cambridge, Massachusetts: The Belknap Press of Harvard University Press (original not read by us) en.wikipedia.org
- Wikipedia, "Ontogeny" (CC BY-SA 4.0), which cites: Robinson, "Ernst Haeckel German embryologist Britannica", Encyclopedia Britannica, 12 February 2022 (original not read by us) en.wikipedia.org
- Barnes, "Ernst Haeckel's Biogenetic Law (1866) The Embryo Project Encyclopedia", embryo.asu.edu, 2014-05-03. facts only, no text reused. embryo.asu.edu
- Wikipedia, "Ontogeny" (CC BY-SA 4.0), which cites: Niko Tinbergen, "On aims and methods of ethology", Zeitschrift für Tierpsychologie, 1963, p. 410–433 (original not read by us) en.wikipedia.org
- Wikipedia, "Ontogeny" (CC BY-SA 4.0), which cites: "Foundations of animal behavior : classic papers with commentaries", 1996 (original not read by us) en.wikipedia.org
- Wikipedia, "Ontogeny" (CC BY-SA 4.0), which cites: "ontogeny Etymology, origin and meaning of ontogeny by etymonline", www.etymonline.com; (original not read by us) en.wikipedia.org
- Wikipedia, "Ontogeny" (CC BY-SA 4.0), which cites: Gilbert, "Ecological Developmental Biology", Sinauer, 2015, p. 170–171; Barnes, "Ernst Haeckel's Biogenetic Law (1866) The Embryo Project Encyclopedia", embryo.asu.edu, 2014-05-03; Gilbert, "Ecological Developmental Biology", Sinauer Associates, Inc., 2015, p. 357 (we also read that source) en.wikipedia.org
- "Juvenile Stage Center for Academic Research and Training in Anthropogeny (CARTA)", carta.anthropogeny.org. facts only, no text reused. carta.anthropogeny.org
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Ontogeny (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
More in Reproduction And Development
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Ontogeny (CC BY-SA 4.0).
- Word definitions: the Codexery glossary, each quoted from its Wikipedia article.
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