phyletic gradualism

The pre-1972 orthodoxy that Eldredge and Gould's 1972 paper explicitly named itself against — "Punctuated equilibria: an alternative to phyletic gradualism." Gradualism holds that morphological change accumulates steadily and directionally within a lineage over its whole fossil range, rather than concentrating at speciation with long intervening stasis. The vault's quantitative-paleobiology cluster treats gradualism operationally as the "directional evolution" model in the paleoTS model set — the mode Hunt's surveys find is rare (~5–13% of fitted sequences), which is the empirical leg gradualism's rejection actually stands on.

References

• claim-punctuated-equilibrium-derives-from-mayr-peripatric-speciation · claim-hunt-2007-directional-evolution-rare-stasis-and-random-walk-split-evenly · claim-hunt-2007-framed-directional-rarity-as-corroborating-punctuated-equilibrium
• Related hubs: entity-punctuated-equilibrium · entity-gene-hunt
• Captures: 2026-07-09-hop-mayr-peripatric-speciation, 2026-07-16-does-gene-hunts-2007-survey-of-250-fossil