( ( If ( ( organic compounds ) ( had ( formed ( ( ( ( in water ) , ) ( rather than ) ) ( in ( the atmosphere ) ) ) ) ) ) ) ( , ( ( the ( lipid-hydrocarbon group ) ) ( ( would ( have ( risen ( to ( ( the surface ) ( because ( of ( insolubility ( and ( low density ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (S (NP (JJ organic) (NNS compounds)) (VP (VBD had) (VP (VBN formed) (PP (PP (IN in) (NP (NN water))) (, ,) (CONJP (RB rather) (IN than)) (PP (IN in) (NP (DT the) (NN atmosphere)))))))) (, ,) (NP (DT the) (JJ lipid-hydrocarbon) (NN group)) (VP (MD would) (VP (VB have) (VP (VBN risen) (PP (TO to) (NP (NP (DT the) (NN surface)) (PP (RB because) (IN of) (NP (JJ insolubility) (CC and) (JJ low) (NN density)))))))) (. .)))
If organic compounds had formed in water, rather than in the atmosphere, the lipid-hydrocarbon group would have risen to the surface because of insolubility and low density.
(ROOT (S (NP (DT A) (NN lipid)) (VP (VBZ is) (NP (NP (CD one)) (PP (IN of) (NP (NP (DT a) (ADJP (RB highly) (JJ diverse)) (NN group)) (PP (IN of) (NP (NP (NNS compounds)) (VP (VBN made) (PRT (RP up)) (ADVP (RB mostly))))) (PP (IN of) (NP (NNS hydrocarbons))))))) (. .)))