Phyletic gradualism

Theory in evolutionary biology

Phyletic gradualism is a model of evolution which theorizes that most speciation is slow, uniform and gradual. When evolution occurs in this mode, it is usually by the steady transformation of a whole species into a new one. In this view no clear line of demarcation exists between an ancestral species and a descendant species, unless splitting occurs. The theory is contrasted with punctuated equilibrium.

This keyword could refer to multiple things. Here are some suggestions: