( ( The population ) ( ( is ( ( the unit ) ( of evolution ) ) ) . ) )
(ROOT (S (NP (DT The) (NN population)) (VP (VBZ is) (NP (NP (DT the) (NN unit)) (PP (IN of) (NP (NN evolution))))) (. .)))
The population is the unit of evolution.
(ROOT (S (NP (NNP Population)) (VP (VBZ is) (NP (NP (DT the) (NN unit)) (PP (IN of) (NP (NN evolution))))) (. .)))