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Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism from the fertilized egg to its mature form. Ontogeny is studied in developmental biology.
The idea that ontogeny recapitulates phylogeny, that is, that the development of an organism exactly mirrors the evolutionary development of the species, is discredited today. However the phenomenon of recapitulation, in which a developing organism will for a time show a similar trait or attribute to that of an ancestral species, only to have it disappear at a later stage is well documented. For example, embryos of the baleen whale still develop teeth at certain embryonic stages, only to later disappear. A more general example is the emergence of what could develop into pharyngeal gill pouches if it were in a lower vertebrate in almost all mammalian embryos at early stages of development. (April, 2001)
[edit] See also
- Important publications in ontogeny
[edit] External links
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The development of phenotype |
| Key concepts: Genotype-phenotype distinction | Norms of reaction | Gene-environment interaction | Heritability | Quantitative genetics |
| Genetic architecture: Dominance relationship | Epistasis | Polygenic inheritance | Pleiotropy | Plasticity | Canalisation | Fitness landscape |
| Non-genetic influences: Epigenetic inheritance | Epigenetics | Maternal effect | dual inheritance theory |
| Developmental architecture: Segmentation | Modularity |
| Evolution of genetic systems: Evolvability | Mutational robustness | Evolution of sex |
| Influential figures: C. H. Waddington | Richard Lewontin |
| Debates: Nature versus nurture |
| List of evolutionary biology topics |