( ( Discusses ( ( ( ( ( overpopulation , ) ( water quality ) ) , ) and ) ( species extinction ) ) ) . )
(ROOT (NP (NP (NNS Discusses)) (NP (NP (NN overpopulation)) (, ,) (NP (NN water) (NN quality)) (, ,) (CC and) (NP (NN species) (NN extinction))) (. .)))
Discusses overpopulation, water quality, and species extinction.
(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)))))) (. .)))