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Gradual Speciation and Punctuated Equilibrium

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State

The gradual model holds lineages diverge in small, steady steps; punctuated equilibrium holds change occurs in rapid bursts, followed by long stasis.

Show

A fossil sequence with steady change across many strata fits the gradual model; sudden change then long unchanged stretches fits punctuated equilibrium.

Watch for

Punctuated equilibrium describes a faster tempo, not a different mechanism — selection still drives change under either model.