( Mabee ( ( is ( working ( to ( gather ( evidence ( that ( might ( confirm ( this theory ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Mabee)) (VP (VBZ is) (VP (VBG working) (S (VP (TO to) (VP (VB gather) (NP (NP (NN evidence)) (SBAR (WHNP (WDT that)) (S (VP (MD might) (VP (VB confirm) (NP (DT this) (NN theory)))))))))))) (. .)))
Mabee is working to gather evidence that might confirm this theory.
(ROOT (S (S (VP (TO To) (VP (VB confirm) (NP (NP (DT the) (NN work)) (PP (IN of) (NP (DT another) (NN scientist))))))) (, ,) (NP (DT a) (NN scientist)) (VP (MD might) (VP (VB replicate) (NP (PRP$ their) (NN work)))) (. .)))