( However ( , ( others ( ( ( ( reproduce sexually ) , ) ( which ( occurs ( in ( several ways ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB However)) (, ,) (NP (NNS others)) (VP (VB reproduce) (ADVP (RB sexually)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ occurs) (PP (IN in) (NP (JJ several) (NNS ways))))))) (. .)))
However, others reproduce sexually, which occurs in several ways.
(ROOT (S (NP (NNS Vertebrates)) (VP (VB reproduce) (ADVP (RB sexually))) (. .)))