( ( ( ( a -RRB- ) ( ( stabilizing ( selection ( b -RRB- ) ) ) gradualism ) ) ( ( c -RRB- ) ( ( directional ( selection ( d -RRB- ) ) ) ( ( punctuated ( equilibrium ( ( e -RRB- ) ( disruptive selection ) ) ) ) 6 ) ) ) ) . )
(ROOT (S (S (LST (LS a) (-RRB- -RRB-)) (NP (JJ stabilizing) (NN selection) (NNS b) (-RRB- -RRB-)) (VP (VBP gradualism))) (S (LST (LS c) (-RRB- -RRB-)) (NP (JJ directional) (NN selection) (NNS d) (-RRB- -RRB-)) (VP (VBD punctuated) (NP (NP (NN equilibrium)) (NP (LST (LS e) (-RRB- -RRB-)) (VBN disruptive) (NN selection))) (NP (CD 6)))) (. .)))
a) stabilizing selection b) gradualism c) directional selection d) punctuated equilibrium e) disruptive selection 6.
(ROOT (S (NP (NNP Darwin)) (VP (VBD believed) (PP (IN in) (NP (NN gradualism)))) (. .)))