( ( A population ) ( ( is ( ( all ( the members ) ) ( of ( ( one species ) ( that ( live ( in ( the ( same area ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN population)) (VP (VBZ is) (NP (NP (PDT all) (DT the) (NNS members)) (PP (IN of) (NP (NP (CD one) (NNS species)) (SBAR (WHNP (WDT that)) (S (VP (VBP live) (PP (IN in) (NP (DT the) (JJ same) (NN area)))))))))) (. .)))
A population is all the members of one species that live in the same area.
(ROOT (S (NP (NP (DT All) (NNS members)) (PP (IN of) (NP (DT a) (NN species) (NN living)))) (ADVP (RB together)) (VP (VB form) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN population))) (. .)))