( This ( ( is ( ( the ( first sign ) ) ( of ( ( ( ( an organ ) , ) ( long ( before ( ( ( ( ( ( ( heart , ) ( GI tract ) ) , ) muscles ) , ) or ) ( other ( organ systems ) ) ) ) ) ) form ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (NP (NP (DT the) (JJ first) (NN sign)) (PP (IN of) (NP (NP (DT an) (NN organ)) (, ,) (ADVP (RB long) (PP (IN before) (NP (NP (NN heart)) (, ,) (NP (NNP GI) (NNP tract)) (, ,) (NP (NNS muscles)) (, ,) (CC or) (NP (JJ other) (NN organ) (NNS systems))))) (NP (NN form)))))) (. .)))
This is the first sign of an organ, long before heart, GI tract, muscles, or other organ systems form.
(ROOT (S (PP (IN In) (NP (NNS humans))) (, ,) (NP (DT the) (NN heart)) (VP (VBZ is) (NP (DT the) (JJ first) (NN organ) (S (VP (TO to) (VP (VP (VB form)) (CC and) (VP (VB become) (ADJP (JJ functional)))))))) (. .)))