The punctuated equilibrium model of evolution suggests that new species appear
A) gradually; as groups become isolated, they slowly evolve through their own individual pathways.
B) only after older species disappear from the fossil record.
C) suddenly after long periods of time with little to no change.
D) gradually after long periods of time with little to no change; as groups become isolated, they slowly evolve through their own individual pathways.
E) gradually over very short periods of time so that intermediate species are often observed in the fossil record.

Question

Quizplus · Accepted Answer

The punctuated equilibrium model posits that species remain relatively unchanged for long periods (stasis) and then undergo rapid changes that lead to the formation of new species, often corresponding to a sudden environmental change or a population becoming isolated. This contrasts with the gradualism model, which suggests slow, steady change over time.

The Punctuated Equilibrium Model of Evolution Suggests That New Species