( ( Genes ( essential ( for ( basic ( life processes ) ) ) ) ) ( ( are ( thought ( to ( be ( often ( ( ( ( ( retained , ) or ) conserved ) , ) ( ( ( through ( ( the evolution ) ( of ( new species ) ) ) ) and ) ( across ( millions ( of generations ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Genes)) (ADJP (JJ essential) (PP (IN for) (NP (JJ basic) (NN life) (NNS processes))))) (VP (VBP are) (VP (VBN thought) (S (VP (TO to) (VP (VB be) (VP (ADVP (RB often)) (VBN retained) (, ,) (CC or) (VBN conserved) (, ,) (PP (PP (IN through) (NP (NP (DT the) (NN evolution)) (PP (IN of) (NP (JJ new) (NNS species))))) (CC and) (PP (IN across) (NP (NP (NNS millions)) (PP (IN of) (NP (NNS generations)))))))))))) (. .)))
Genes essential for basic life processes are thought to be often retained, or conserved, through the evolution of new species and across millions of generations.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (NNS changes)) (PP (IN in) (NP (NP (DT the) (NNS genes)) (PP (IN of) (NP (DT a) (NN species)))))) (VP (VBP result) (PP (IN in) (NP (DT a) (JJ new) (NN species)))))) (, ,) (NP (DT the) (NN process)) (VP (VBZ is) (VP (VBN called) (NP (JJ biological) (NN evolution)))) (. .)))