( ( A population ) ( ( consists ( of ( organisms ( of ( ( the ( same species ) ) ( that ( live ( in ( the ( same area ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN population)) (VP (VBZ consists) (PP (IN of) (NP (NP (NNS organisms)) (PP (IN of) (NP (NP (DT the) (JJ same) (NN species)) (SBAR (WHNP (WDT that)) (S (VP (VBP live) (PP (IN in) (NP (DT the) (JJ same) (NN area))))))))))) (. .)))
A population consists of organisms of the same species that live in the same area.
(ROOT (S (NP (NP (PDT All) (DT the) (NNS members)) (PP (IN of) (NP (NP (DT a) (NN species)) (SBAR (WHNP (WDT that)) (S (VP (VBP live) (PP (IN in) (NP (DT the) (JJ same) (NN area))))))))) (VP (VBP form) (NP (DT a) (NN population))) (. .)))
All the members of a species that live in the same area form a population.