Punctuated Equilibrium
Etymology
Proposed in 1972 by paleontologists Niles Eldredge and Stephen Jay Gould to explain gaps in the fossil record. "Punctuated" is from Latin "punctuare" ("to mark with points"), and "equilibrium" from Latin "aequilibrium" ("even balance") — long balances, punctuated by abrupt jumps.
noun phrase · /PUNK-choo-ay-ted ee-kwih-LIB-ree-um/
The idea that change comes not gradually but in rare, rapid bursts separating long stretches of near-stillness.
What it names
A model for how so many things actually evolve — species, technologies, institutions — through long plateaus of stability broken by sudden, concentrated upheaval.
Example
His career looked flat for a decade, then leapt twice in two years — punctuated equilibrium, not steady climbing.
Related idea
It stands against gradualism, the assumption that change accrues in even increments; and unlike a one-off phase transition, it describes a whole rhythm of stasis and burst repeating over time.