( ( Research Notebook ) ( ( ( ( The ( first fungi ) ) ( may ( have ( appeared ( on ( land ( ( ( ( ( ( ( a billion ) years ) ago ) , ) nearly ) ( ( ( ( ( twice as ) long ) ago ) as ) previously ) ) thought ) ) ) ) ) ) ) , ) ( ( say ( scientists ( ( studying mutations ) ( in ( plant genes ) ) ) ) ) . ) ) )
(ROOT (S (NP (NNP Research) (NNP Notebook)) (PRN (S (NP (DT The) (JJ first) (NNS fungi)) (VP (MD may) (VP (VB have) (VP (VBN appeared) (PP (IN on) (NP (NP (NN land)) (VP (ADVP (ADVP (NP (QP (DT a) (CD billion)) (NNS years)) (IN ago)) (, ,) (RB nearly) (ADVP (ADVP (ADVP (RB twice) (RB as)) (RB long) (RB ago)) (RB as) (RB previously))) (VBN thought)))))))) (, ,)) (VP (VBP say) (S (NP (NNS scientists)) (VP (VBG studying) (NP (NNS mutations)) (PP (IN in) (NP (NN plant) (NNS genes)))))) (. .)))
Research Notebook The first fungi may have appeared on land a billion years ago, nearly twice as long ago as previously thought, say scientists studying mutations in plant genes.
(ROOT (S (NP (DT The) (JJ first) (VBG living) (NNS cells)) (VP (MD may) (VP (VB have) (VP (VBN evolved) (ADVP (NP (QP (RB around) (CD 4) (CD billion)) (NNS years)) (RB ago))))) (. .)))