gradualism (grāj'-ə-lĭz'əm) The theory that new species evolve from existing species through gradual, often imperceptible changes rather than through abrupt, major changes. The small changes are believed to result in perceptible changes over long periods of time. Compare punctuated equilibrium. |
The belief that changes in the Earth, such as the development of species, have taken place slowly, without sudden and violent transitions. (Compare punctuated equilibrium and catastrophism.)