( ( Natural selection ) ( ( is ( ( the process ) ( ( by which ) ( ( ( heritable traits ) ( that ( make ( it ( ( more ( likely ( for ( an organism ) ) ) ) ( to ( ( ( survive and ) successfully ) reproduce ) ) ) ) ) ) ) ( ( become ( more common ) ) ( in ( ( a population ) ( over ( successive generations ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Natural) (NN selection)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (SBAR (WHPP (IN by) (WHNP (WDT which))) (S (NP (NP (JJ heritable) (NNS traits)) (SBAR (WHNP (WDT that)) (S (VP (VBP make) (S (NP (PRP it)) (ADJP (RBR more) (JJ likely) (PP (IN for) (NP (DT an) (NN organism)))) (S (VP (TO to) (VP (VP (VB survive)) (CC and) (ADVP (RB successfully)) (VP (VB reproduce)))))))))) (VP (VBP become) (ADJP (RBR more) (JJ common)) (PP (IN in) (NP (NP (DT a) (NN population)) (PP (IN over) (NP (JJ successive) (NNS generations)))))))))) (. .)))
Natural selection is the process by which heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations.
(ROOT (S (NP (JJ Natural) (NN selection)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (SBAR (WHNP (WDT that)) (S (VP (VBZ allows) (NP (NNS organisms)) (PP (IN with) (NP (JJR better) (NNS traits) (S (VP (TO to) (VP (VB survive) (CC and) (VB produce))))))))))) (. .)))