( Hybridization ( ( results ( when ( an ( ( introduced ( species mates ) ) ( with ( ( a ( native species ) ) ( producing ( hybrid offspring ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Hybridization)) (VP (VBZ results) (SBAR (WHADVP (WRB when)) (S (NP (DT an)) (VP (VBD introduced) (NP (NN species) (NNS mates)) (PP (IN with) (NP (NP (DT a) (JJ native) (NN species)) (VP (VBG producing) (NP (JJ hybrid) (NN offspring))))))))) (. .)))
Hybridization results when an introduced species mates with a native species producing hybrid offspring.
(ROOT (S (SBAR (IN If) (S (NP (CD two) (NNS populations)) (VP (VBP do) (RB not) (VP (VB mate) (CC and) (VB produce) (NP (ADJP (JJ fertile)) (NN offspring)))))) (, ,) (NP (JJ separate) (NNS species)) (VP (VBP result)) (. .)))