Written by Wesley R. Elsberry with Qwen3 Max. Last revised: 2024-05-20.
Summary: Punctuated equilibria (PE), proposed by Niles Eldredge and Stephen Jay Gould in 1972, describes a dominant pattern in the fossil record: most species exhibit long periods of morphological stability (“stasis”) interrupted by geologically rapid bursts of change associated with speciation.
While PE was framed as a challenge to “phyletic gradualism,” its strongest empirical and theoretical foundation lies not in overturning Darwinism, but in applying Ernst Mayr’s model of peripatric speciation to paleontological data—and in confronting the operational reality of how species are recognized in deep time.