Page "Punctuated equilibrium" Paragraph 2

Punctuated equilibrium is commonly contrasted against the theory of phyletic gradualism, which states that evolution generally occurs uniformly and by the steady and gradual transformation of whole lineages ( called anagenesis ).

In this view, evolution is seen as generally smooth and continuous.

In 1972, paleontologists Niles Eldredge and Stephen Jay Gould published a landmark paper developing this theory and called it punctuated equilibria.

Their paper built upon Ernst Mayr's theory of geographic speciation, I. Michael Lerner's theories of developmental and genetic homeostasis, as well as their own empirical research.

Eldredge and Gould proposed that the degree of gradualism commonly attributed to Charles Darwin is virtually nonexistent in the fossil record, and that stasis dominates the history of most fossil species.