( ( ( ( ( ( Two to ) three ) billion ) years ) ago ) ( , ( ( the ( molecular structure ) ) ( ( evolved ( into ( ( a ( multi-celled organism ) ) ( which ( evolved ( into ( animals ( , ( ( plants and ) vertebrates ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (NP (QP (CD Two) (TO to) (CD three) (CD billion)) (NNS years)) (RB ago)) (, ,) (NP (DT the) (JJ molecular) (NN structure)) (VP (VBD evolved) (PP (IN into) (NP (NP (DT a) (JJ multi-celled) (NN organism)) (SBAR (WHNP (WDT which)) (S (VP (VBN evolved) (PP (IN into) (NP (NNS animals) (, ,) (NNS plants) (CC and) (NNS vertebrates))))))))) (. .)))
Two to three billion years ago, the molecular structure evolved into a multi-celled organism which evolved into animals, plants and vertebrates.
(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))))) (. .)))