preformation theory
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Preformation theory was a discredited biological idea prevalent until the 18th century. It proposed that germ cells contained a fully formed, miniature organism (a homunculus) and that development was merely an increase in size. This contrasted with the theory of epigenesis, which suggested that sex cells were undifferentiated and that development involved gradual, orderly transformations. Early microscopists even claimed to see tiny human figures within sperm cells. Modern embryology has shown that development is a complex process of differentiation, disproving preformationism.12345
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geneticsPreformation and natural selectionIn the two millennia between the lives of Aristotle and Mendel, few new ideas were recorded on the nature of heredity. In the 17th and 18th centuries the idea of preformation was introduced. Scientists using the newly developed microscopes imagined that…
Read MoreIn the two millennia between the lives of Aristotle and Mendel, few new ideas were recorded on the nature of heredity. In the 17th and 18th centuries the idea of preformation was introduced. Scientists using the newly developed microscopes imagined that…
Read More- heredityPreformism and epigenesis
A notion that was widespread among pioneer biologists in the 18th century was that the fetus, and hence the adult organism that develops from it, is preformed in the sex cells. Some early microscopists even imagined that they saw a tiny homunculus,…
Read MoreA notion that was widespread among pioneer biologists in the 18th century was that the fetus, and hence the adult organism that develops from it, is preformed in the sex cells. Some early microscopists even imagined that they saw a tiny homunculus,…
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