What is punctuated equilibrium?
Darwinism is founded on macroevolution occurring gradually over long periods of time. Undisputed examples of it should be blatantly obvious at every level and in every era, especially after the five major extinction events that have dominated the timeline of complex life on Earth. However, after each such extinction, when 50% to 90% of all life forms were destroyed and the fossil record was essentially wiped clean, there was a brief period of stability (thousands of years), followed by a relatively rapid filling (a few million years) of vacated ecological niches.
What paleontologists do get excited about are topics like the average rate of evolution. When exceptionally complete fossil sites are studied, usually a mix of patterns are seen: some species still seem to appear suddenly (within a few hundred thousand years), while others clearly appear gradually (over many millions of years). Once they arise, some species stay mostly the same, while others continue to change gradually. Paleontologists usually attribute these differences to a mix of slow evolution (“gradualism”) and rapid evolution (or “punctuated equilibrium”: sudden bursts of evolution followed by stasis), in combination with the immigration of new species from the as-yet-undiscovered places where they first arose. There’s been a heated debate about which of these modes of evolution is most common, and this debate has been largely misquoted by laypeople. Virtually all of the quotes of paleontologists saying things like “the gaps in the fossil record are real” are taken out of contex
