Gradualism

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Gradualism is a theory which holds that profound change is the cumulative product of slow but continuous processes. The theory was proposed in 1795 by James Hutton, a Scottish geologist, and was later incorporated into Charles Lyell's theory of uniformitarianism. Tenets from both theories were applied to biology and formed the basis of early evolutionary theory.

Charles Darwin was influenced by Charles Lyell's Principles of Geology, which explained both uniformitarian methodology and theory. Using methodological uniformitarianism, which states that one cannot make an appeal to any force or phenomenon which cannot presently be observed (see catastrophism), Darwin theorized that the evolutionary process must occur gradually, not in saltations, since saltations are not presently observed, and extreme deviations from the usual phenotypic variation would be more likely to be selected against.

Gradualism is frequently contrasted with catastrophism.

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