( ( gradualism ( versus ( ( punctuated equilibrium ) ( as ( two ( different views ) ) ) ) ) ) ; )
(ROOT (NP (NP (NN gradualism)) (PP (IN versus) (NP (NP (JJ punctuated) (NN equilibrium)) (PP (IN as) (NP (CD two) (JJ different) (NNS views))))) (: ;)))
gradualism versus punctuated equilibrium as two different views;
(ROOT (S (NP (NNP Darwin)) (VP (VBD believed) (PP (IN in) (NP (NN gradualism)))) (. .)))