( ( ( ( ( Microevolution , ) or ) ( change ( beneath ( the ( species level ) ) ) ) ) , ) ( ( may ( be ( thought ( of ( as ( ( ( ( ( relatively small ) ( scale changes ) ) ( in ( the functional ) ) ) and ) ( ( genetic constituencies ) ( of ( populations ( of ( organisms ( ( correlated ( either ( ( ( with ( genetic drift ) ) or ) ( with ( adaptation ( in response ) ) ) ) ) ) ( to ( environmental fluctuations ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Microevolution)) (, ,) (CC or) (NP (NP (NN change)) (PP (IN beneath) (NP (DT the) (NN species) (NN level)))) (, ,)) (VP (MD may) (VP (VB be) (VP (VBN thought) (PP (IN of) (IN as) (NP (NP (NP (ADJP (RB relatively) (JJ small)) (NN scale) (NNS changes)) (PP (IN in) (NP (DT the) (NN functional)))) (CC and) (NP (NP (JJ genetic) (NNS constituencies)) (PP (IN of) (NP (NP (NNS populations)) (PP (IN of) (NP (NP (NNS organisms)) (VP (VBN correlated) (PP (CC either) (PP (IN with) (NP (JJ genetic) (NN drift))) (CC or) (PP (IN with) (NP (NP (NN adaptation)) (PP (IN in) (NP (NN response)))))) (PP (TO to) (NP (JJ environmental) (NNS fluctuations)))))))))))))) (. .)))
Microevolution, or change beneath the species level, may be thought of as relatively small scale changes in the functional and genetic constituencies of populations of organisms correlated either with genetic drift or with adaptation in response to environmental fluctuations.
(ROOT (S (NP (NNP Microevolution)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (SBAR (WHPP (IN by) (WHNP (WDT which))) (S (NP (NNS organisms)) (VP (VBP change) (PP (IN in) (NP (NP (JJ small) (NNS ways)) (PP (IN over) (NP (NN time)))))))))) (. .)))