Question

two models for the speed of speciation are based on patterns in the fossil record. which of the following statements describes the punctuated equilibrium model of evolution?
natural selection is unimportant as a mechanism of evolution
most evolution occurs in sympatric populations
given enough time, most existing species will gradually branch into new species
species accumulate their unique features rapidly, then change little for the duration of the species

Explanation:

To determine the correct statement about the punctuated equilibrium model of evolution:

1. Recall the definition of punctuated equilibrium: species experience rapid bursts of evolutionary change (acquiring unique features quickly) followed by long periods of stasis (little to no change).
2. Analyze each option:

• "Natural selection is unimportant..." is incorrect (natural selection is a key evolutionary mechanism).
• "Most evolution occurs in sympatric populations" is incorrect (punctuated equilibrium does not focus on sympatric vs. allopatric speciation context here).
• "Given enough time... gradually branch" describes gradualism (the opposite of punctuated equilibrium).
• "Species accumulate their unique features rapidly, then change little..." matches the punctuated equilibrium model.

Answer:

D. Species accumulate their unique features rapidly, then change little for the duration of the species