( ( Five ( global ( mass extinctions ) ) ) ( ( ( have radically ) ( ( altered ( ( the ( composition ( and ( evolutionary course ) ) ) ) ( of life ) ) ) ( during ( the ( past ( half-billion years ) ) ) ) ) ) . ) )
(ROOT (S (NP (CD Five) (JJ global) (JJ mass) (NNS extinctions)) (VP (VBP have) (ADVP (RB radically)) (VP (VBN altered) (NP (NP (DT the) (NN composition) (CC and) (JJ evolutionary) (NN course)) (PP (IN of) (NP (NN life)))) (PP (IN during) (NP (DT the) (JJ past) (JJ half-billion) (NNS years))))) (. .)))
Five global mass extinctions have radically altered the composition and evolutionary course of life during the past half-billion years.
(ROOT (S (NP (CD Five) (JJ mass) (NNS distinctions)) (VP (VBP have) (ADVP (RB radically)) (VP (VBN altered) (NP (NP (DT the) (NN history)) (PP (IN of) (NP (NN life)))))) (. .)))