punctuated equilibrium

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punctuated equilibrium Theory, expounded by US palaeontologists Stephen Jay Gould and Niles Eldredge in 1972, that is strongly sceptical of the notion of gradual change in the evolution of the natural world, as advocated by Charles Darwin. Fossil records rarely document the gradual development of a new species, rather showing its seemingly sudden appearance. Darwin argues that this is due to gaps in the fossil records. Punctuated equilibrium explains this by describing each species as in a steady state (equilibrium), which is punctuated by brief but intense periods of sudden change that give rise to new species.

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