Given that preformation has been soundly debunked in favor of a complex developmental process resembling epigenesis, the author of your quote is presumably saying that there is no one left who still thinks preformation is a viable theory.
32.
Others, including Thomas Hunt Morgan and Oscar Hertwig, attempted to separate the two cells, for the matter was of great importance, particularly to the arguments between proponents of epigenesis and preformation, but satisfactory results could not be achieved.
33.
By the 20th century, the concept of epigenesis the interaction between a genetic program and environment was established and in the second half of the 20th century researchers had evidence that environmental factors can cause malformations and even trans-generational effects.
34.
Caspar Friedrich Wolff ( 1733 1794 ) is considered to be the father of epigenesis in embryology, that is, he marks the point when embryonic development began to be described in terms of the proliferation of cells rather than the incarnation of a preformed soul.
35.
"The Rosicrucian Cosmo-Conception ", a Rosicrucian text written by Max Heindel, advances the concept of epigenesis as the " key " related to the evolution ( after an " involutionary " period ) of human beings.
36.
He returned to physical science, but to the speculative side of it, in his " Considerations sur les corps organis�es " ( Amsterdam, 1762 ), designed to refute the theory of epigenesis, and to explain and defend the doctrine of pre-existent germs.
37.
In 1759, Caspar Friedrich Wolff, a German embryologist provided evidence for the ancient idea of epigenesis, that is preformed life, that is a chick out of unformed substance and his dispute with von Haller brought the issue of life to the forefront of natural science and philosophy.
38.
Furthermore, apart from those distinctions ( preformationism-epigenesis and genetic-epigenetic ), the terms preformistic development, epigenetic development and somatic embryogenesis are also used in another context, in relation to the Weismannist development ( either preformistic or epigenetic ) that in which there is a distinct germ line.
39.
:The roots epigenesis ( biology ) and epigenetics are clearly different in meaning; " epigenesis " applies to a theory of developmental embryology and " epigenetics " relates, in a very general sense, to structural changes that control the expression of genes ( though interestingly quite important in regulating embryogenesis ).
40.
:The roots epigenesis ( biology ) and epigenetics are clearly different in meaning; " epigenesis " applies to a theory of developmental embryology and " epigenetics " relates, in a very general sense, to structural changes that control the expression of genes ( though interestingly quite important in regulating embryogenesis ).
