epigenesis

ep·i·gen·e·sis  (p-jn-ss)

n.

1. Biology The theory that an individual is developed by successive differentiation of an unstructured egg rather than by a simple enlarging of a preformed entity.

2. Geology Change in the mineral content of a rock because of outside influences.

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epi·ge·netic (-j-ntk) adj.

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epigenesis [ˌɛpɪˈdʒɛnɪsɪs]

n

1. (Life Sciences & Allied Applications / Biology) 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]

2. (Earth Sciences / Geological Science) the formation or alteration of rocks after the surrounding rock has been formed

3. (Earth Sciences / Geological Science) alteration of the mineral composition of a rock by external agents: a type of metamorphism

epigenesist , epigenist [ɪˈpɪdʒɪnɪst] n

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epigenesis

1. the appearance of a secondary symptom in a disease or illness.
2. the secondary symptom itself. See also biology; geology. — epigenetic, adj.

See also: Disease and Illness

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the biological theory that germ cells are structureless and the embryo develops through the action of environment on the protoplasm. Cf. preformation. See also birth; disease and illness; geology. — epigenetic, adj.

See also: Biology

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the formation of a cell as a new product and not as the result of development from some existing cell. — epigenetic, adj.

See also: Cells

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the process of metamorphism. See also biology; disease and illness. — epigenetic, adj.

See also: Geology

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the theory that embryonic development is totally controlled by the cell’s environment. Cf. syngenesis. — epigenesist, n. — epigenetic, adj.

See also: Birth

Thesaurus

Noun

1.

epigenesis - a geological change in the mineral content of rock after the rock has formed metamorphism - change in the structure of rock by natural agencies such as pressure or heat or introduction of new chemical substances