from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun 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.
- noun Geology Change in the mineral content of a rock because of outside influences.
from The Century Dictionary.
- noun The coming into being in the act or process of generation or reproduction; the theory or doctrine of generation in which the germ is held to be actually procreated by the parents, not simply expanded or unfolded or made to grow out of an ovum or spermatozoön in which it preëxisted or had been preformed.
- noun In geology, same as
- noun In pathology, an accessory symptom; a new symptom that does not indicate a change in the nature of a disease.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Biol.) The theory of generation which holds that the germ is created entirely new, not merely expanded, by the procreative power of the parents. It is opposed to the theory of
evolution, also to syngenesis.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun biology The theory that an
organismdevelops by differentiationfrom an unstructured eggrather than by simple enlargingof something preformed.
- noun geology
changesin the mineral contentof rockafter its formation
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a geological change in the mineral content of rock after the rock has formed
from Wiktionary, Creative Commons Attribution/Share-Alike License
To-day we can scarcely call epigenesis a THEORY, because we are convinced it is a fact, and can demonstrate it at any moment with the aid of the microscope.
Its "epigenesis" is shown to be a literary example of the phases of cell division, with discussions of its prophase, metaphase, anaphase, and telophase.
This point established, two hypotheses remain: that of 'pre-existence' and that of 'epigenesis'.
"epigenesis", viz., that the development of the embryo is real successive production of visible manifoldness, real construction of new parts, goes back to Aristotle.
(P. 163.) "The doctrine of 'epigenesis' is derived from Harvey: following by ocular inspection the development of the new being in the Windsor does, he saw each part appear successively, and taking the moment of
This literature shows that symbiogenesis, interspecific fusions (hybridogenesis, gene transfers of various types, karyotypic fissioning, and other forms of acquisition of "foreign genomes" or epigenesis) are more important than the slow gradual accumulation of mutation or sexual mergers.
Suzan Mazur: Then there's epigenesis, where a chemical layer is laid down on top of the genes resulting from various stresses on the organism, and the resulting traits (including disease) can be passed on without changes to the DNA.
If preformationism is all about blueprints, epigenesis is about something more like a recipe or a computer program.
The historical alternative to preformationism is epigenesis.
However, as a decade of Bolivarian Revolution can witness, sane human cosmic existence covers our whole historic trajectory, the arduous revolutionary paths of our genesis, epigenesis and synthesis, from where we came, to where we are and to whither we are going.