What is punctuated equilibrium?
Punctuated equilibrium, as Niles Eldredge and I proposed, describes a pattern of evolution observed in the fossil record. It posits that species tend to remain unchanged for long periods (stasis) and then experience relatively brief periods of rapid evolutionary change, often leading to the formation of new species. This contrasts with gradualism, which suggests continuous, slow change over time. The fossil record often supports this more jerky pattern of change, where species appear, persist, and then disappear, with transitional forms being relatively rare.
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