noun
epigenesis
A biological theory that an organism develops from an undifferentiated cell through a series of steps, as opposed to preformation. Contrasts with 前成説 (preformation theory).
See also: 前成説
後成説は、発生生物学の歴史において重要な概念である。
Epigenesis is an important concept in the history of developmental biology.
前成説 (preformation theory) is the opposing theory that organisms develop from miniature versions of themselves. 後成説 (epigenesis) holds that development is a stepwise process from an undifferentiated state.
From 後成 (kōsei, 'epigenetic') + 説 (setsu, 'theory'). The term is a calque from Western biological terminology.