epigenesis

American  

[ep-i-jen-uh-sis] / ˌɛp ɪˈdʒɛn ə sɪs /

noun

1. Biology. the theory that an embryo develops from the successive differentiation of an originally undifferentiated structure (opposed to preformation).

2. Genetics. the approximately stepwise process by which genetic information is modified and translated into the substance and behavior of an organism.

3. Geology. ore deposition subsequent to the original formation of the enclosing country rock.

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epigenesis British  

/ ɪˈpɪdʒɪnɪst, ˌɛpɪˈdʒɛnɪsɪs /

noun

1. the widely accepted theory that an individual animal or plant develops by the gradual differentiation and elaboration of a fertilized egg cell Compare preformation

2. the formation or alteration of rocks after the surrounding rock has been formed

3. alteration of the mineral composition of a rock by external agents: a type of metamorphism

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Other Word Forms

• epigenesist noun
• epigenetic adjective
• epigenetically adverb
• epigenist noun

Etymology

Origin of epigenesis

First recorded in 1800–10; epi- + -genesis

Example Sentences

There was no epigenesis in the case of giraffes’ long necks nor in more than 99% of the workings of natural selection in other contexts.

From The Wall Street Journal • Mar. 20, 2026

But, with her mouse work alone, it looks as if Ms Chan has cracked an important part of the puzzle of intergenerational epigenesis.

From Economist • Feb. 22, 2018

The chemical processes that alter the genes in epigenesis – methylation and deacetylation of the packaging proteins of the genes, the histones – are fairly well understood.

From The Guardian • Aug. 8, 2012

A more intriguing possibility, though, is that the relevant genes are affected by epigenesis, a process in which chemicals attached to the DNA control its activity.

From Economist • Sep. 30, 2010

Actually, Harvey's exposition of epigenesis, albeit clear, is not totally impressive, since it is largely a reflection of Aristotle's influence.

From Medical Investigation in Seventeenth Century England Papers Read at a Clark Library Seminar, October 14, 1967 by Bodemer, Charles W.