( Microevolution ( ( ( occurs ( over ( ( a ( short period ) ) ( of time ) ) ) ) ( in ( ( ( a population ) or ) species ) ) ) . ) )
(ROOT (S (NP (NNP Microevolution)) (VP (VBZ occurs) (PP (IN over) (NP (NP (DT a) (JJ short) (NN period)) (PP (IN of) (NP (NN time))))) (PP (IN in) (NP (NP (DT a) (NN population)) (CC or) (NP (NNS species))))) (. .)))
Microevolution occurs over a short period of time in a population or species.
(ROOT (S (NP (NP (NNP Evolution)) (SBAR (WHNP (WDT that)) (S (VP (VBZ occurs) (PP (IN over) (NP (NP (DT a) (JJ short) (NN period)) (PP (IN of) (NP (NN time))))))))) (VP (VBZ is) (VP (VBN known) (PP (IN as) (NP (NN microevolution))))) (. .)))