theory of preformation
A scientist in the 18th century studies the theory of preformation using a microscope.
Noun: A biological theory, historically prominent in the 18th century but now scientifically discredited, which proposed that an organism develops from a germ cell that already contains a complete, miniature preformed version of itself (called a homunculus), requiring only growth or enlargement to reach maturity.
The term theory of preformation is used exclusively in historical and scientific contexts to describe this obsolete concept in embryology and the history of science. * The debate between the theory of preformation and the theory of epigenesis was central to 18th-century biology. * Modern embryology completely rejects the theory of preformation.
- In historical analysis: The term is used to discuss the philosophical and scientific paradigms of the past.
- The theory of preformation reflected a mechanistic view of development prevalent during the Scientific Revolution.
- Preformationism (n): Another name for the same historical theory.
- Preformationist (n/adj): A proponent of the theory, or relating to it.
- Homunculus (n): The hypothesized miniature, fully formed human believed to exist within the sperm or egg cell according to this theory.
- Preformationism
- Theory of epigenesis (the opposing, and ultimately correct, theory that an organism develops progressively from an undifferentiated state).
A scientist in the 18th century studies the theory of preformation using a microscope.
- a theory (popular in the 18th century and now discredited) that an individual develops by simple enlargement of a tiny fully formed organism (a homunculus) that exists in the germ cell