In the
history of biology,
preformationism (or
preformism) is a formerly-popular theory that organisms develop from miniature versions of themselves. Instead of assembly from parts, preformationists believed that the
form of living things exist, in real terms, prior to their
development. It suggests that all
organisms were created at the same time, and that succeeding generations grow from
homunculi, or
animalcules, that have existed since the beginning of creation.