There was no evidence of dissection.
 there is evidence of dissection
(ROOT (S (NP (EX There)) (VP (VBD was) (NP (NP (DT no) (NN evidence)) (PP (IN of) (NP (NN dissection))))) (. .)))
(ROOT (S (NP (EX there)) (VP (VBZ is) (NP (NP (NN evidence)) (PP (IN of) (NP (NN dissection)))))))
( There ( ( was ( ( no evidence ) ( of dissection ) ) ) . ) )
( there ( is ( evidence ( of dissection ) ) ) )