( ( ( ( Both ( punctuated equilibrium ) ) and ) ( phyletic gradualism ) ) ( ( occur ( in nature ) ) . ) )
(ROOT (S (NP (NP (DT Both) (JJ punctuated) (NN equilibrium)) (CC and) (NP (JJ phyletic) (NN gradualism))) (VP (VBP occur) (PP (IN in) (NP (NN nature)))) (. .)))
Both punctuated equilibrium and phyletic gradualism occur in  nature.
(ROOT (S (NP (NNP Darwin)) (VP (VBD believed) (PP (IN in) (NP (NN gradualism)))) (. .)))