( ( When ( ( Carl Woese ) ( first ( published ( his ( three-domain system ) ) ) ) ) ) ( , ( it ( ( was ( believed ( that ( ( ( ( ( ( ( the ( domains Bacteria ) ) , ) Archaea ) , ) and ) Eukarya ) ( were ( ( ( equally old ) and ) ( equally ( related ( on ( ( the tree ) ( of life ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNP Carl) (NNP Woese)) (ADVP (RB first)) (VP (VBD published) (NP (PRP$ his) (JJ three-domain) (NN system))))) (, ,) (NP (PRP it)) (VP (VBD was) (VP (VBN believed) (SBAR (IN that) (S (NP (NP (DT the) (JJ domains) (NNS Bacteria)) (, ,) (NP (NNP Archaea)) (, ,) (CC and) (NP (NNP Eukarya))) (VP (VBD were) (ADJP (ADJP (RB equally) (JJ old)) (CC and) (ADJP (RB equally) (VBN related) (PP (IN on) (NP (NP (DT the) (NN tree)) (PP (IN of) (NP (NN life)))))))))))) (. .)))
When Carl Woese first published his three-domain system, it was believed that the domains Bacteria, Archaea, and Eukarya were equally old and equally related on the tree of life.
(ROOT (S (NP (NNP Carl) (NNP woese)) (VP (VBN constructed) (NP (DT a) (NN tree) (NN diagram)) (, ,) (S (VP (VBG separating) (NP (VBG living) (NNS organisms)) (PP (IN into) (NP (CD three) (NNS domains)))))) (. .)))