( This ( ( is ( called ( sympatric speciation ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (VP (VBN called) (NP (JJ sympatric) (NN speciation)))) (. .)))
This is called sympatric speciation.
(ROOT (S (NP (JJ Sympatric) (NN speciation)) (VP (VBZ is) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (JJ new) (NN species)) (VP (VBZ arises) (PP (IN without) (NP (JJ geographic) (NN separation))))))) (. .)))