Gradualism

Gradualism is the belief in or the policy of change by gradual, often slow stages.

Geology and biology
In science, gradualism is a theory holding that profound change is the cumulative product of slow but continuous processes, often contrasted with catastrophism. The theory was proposed by James Hutton 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 Lyell's uniformitarianism and theorized that the evolutionary process must occur gradually, and not in saltations. The gradualist view of evolution has been very critical of saltationism.

Phyletic gradualism
Phyletic gradualism is a model of evolution which theorizes that most speciation is slow, uniform, and gradual. It is often associated with the neo-Darwinian synthetic theory of evolution. The term was coined by Stephen Jay Gould and Niles Eldredge to contrast with their model of punctuated equilibrium.

Politics
In politics, gradualism is ideal of gradual reform rather than change through revolt or other sudden means. In American history, it often refers specifically to proposals for a slow phasing-out of slavery, or later of racial segregation.