( ( ( ( ( ( Signals , ) contexts ) , ) and ) ( mechanism ( of ( ( social communication ) ( in animals ) ) ) ) ) . )
(ROOT (NP (NP (NNS Signals)) (, ,) (NP (NNS contexts)) (, ,) (CC and) (NP (NP (NN mechanism)) (PP (IN of) (NP (NP (JJ social) (NN communication)) (PP (IN in) (NP (NNS animals)))))) (. .)))
Signals, contexts, and mechanism of social communication in animals.
(ROOT (S (PP (IN For) (NP (JJ social) (NNS animals))) (, ,) (NP (NN communication)) (VP (VBZ essential)) (. .)))