( ( Chimpanzees ( on ( the ( other hand ) ) ) ) ( ( ( ( are promiscuous ) , ) ( because ( ( neither sex ) ( ( forms ( lasting bonds ) ) ( with ( ( the partners ) ( it ( mates with ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Chimpanzees)) (PP (IN on) (NP (DT the) (JJ other) (NN hand)))) (VP (VBP are) (ADJP (JJ promiscuous)) (, ,) (SBAR (IN because) (S (NP (DT neither) (NN sex)) (VP (VBZ forms) (NP (JJ lasting) (NNS bonds)) (PP (IN with) (NP (NP (DT the) (NNS partners)) (SBAR (S (NP (PRP it)) (VP (VBZ mates) (PP (IN with))))))))))) (. .)))
Chimpanzees on the other hand are promiscuous, because neither sex forms lasting bonds with the partners it mates with.
(ROOT (S (S (VP (VBG Mating) (PP (IN with) (NP (DT no) (JJ strong) (NNS pair-bonds))))) (VP (VBZ is) (VP (VBN called) (NP (JJ promiscuous) (NN mating)))) (. .)))