( ( If so ) ( , ( ( ( then ( the tracing ) ) ( of ( the pedigree ) ) ) ( ( ( can safely ) ( be left ) ) . ) ) ) )
(ROOT (S (SBAR (IN If) (FRAG (ADVP (RB so)))) (, ,) (NP (NP (RB then) (DT the) (NN tracing)) (PP (IN of) (NP (DT the) (NN pedigree)))) (VP (MD can) (ADVP (RB safely)) (VP (VB be) (VP (VBN left)))) (. .)))
If so, then the tracing of the pedigree can safely be left.
(ROOT (S (NP (DT The) (JJ pedigree) (NN chart) (NN model)) (VP (MD can) (VP (VB be) (VP (VBN used) (S (VP (TO to) (VP (VB trace) (NP (JJ genetic) (NN inheritance)))))))) (. .)))
The pedigree chart model can be used to trace genetic inheritance.