( ( ( ( ( ( The prokaryotes ) ( thus ( were ( the ( earliest organisms ) ) ) ) ) , ) and ) ( they ( ( lived and ) ( ( evolved ( all ( alone ( on Earth ) ) ) ) ( for ( ( 2 billion ) years ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT The) (NNS prokaryotes)) (ADVP (RB thus)) (VP (VBD were) (NP (DT the) (JJS earliest) (NNS organisms)))) (, ,) (CC and) (S (NP (PRP they)) (VP (VP (VBD lived)) (CC and) (VP (VBD evolved) (ADVP (DT all) (JJ alone) (PP (IN on) (NP (NNP Earth)))) (PP (IN for) (NP (QP (CD 2) (CD billion)) (NNS years)))))) (. .)))
The prokaryotes thus were the earliest organisms, and they lived and evolved all alone on Earth for 2 billion years.
(ROOT (S (NP (NNS Prokaryotes)) (VP (VBD were) (NP (NP (DT the) (JJ first) (NN living) (NNS things)) (SBAR (S (VP (TO to) (VP (VB evolve) (PP (IN on) (NP (NN earth))))))))) (. .)))