( It ( ( ( 's not ) ( as ( if ( humans ( ( have never ) ( caused ( ( the extinction ) ( of species ) ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (PRP It)) (VP (VBZ 's) (RB not) (SBAR (RB as) (IN if) (S (NP (NNS humans)) (VP (VBP have) (ADVP (RB never)) (VP (VBN caused) (NP (NP (DT the) (NN extinction)) (PP (IN of) (NP (NNS species))))))))) (: ;)))
It's not as if humans have never caused the extinction of species;
(ROOT (S (NP (NNP Human) (NNP overpopulation)) (VP (VBZ is) (VP (VP (VBG crowding) (PRT (RP out)) (NP (JJ other) (NNS species))) (CC and) (VP (VBG making) (S (NP (NP (PDT all) (DT the) (JJ other) (NNS causes)) (PP (IN of) (NP (NN extinction)))) (ADJP (RBR worse)))))) (. .)))