( ( Assess ( ( the factors ) ( that ( cause ( natural selection ) ) ) ) ) . )
(ROOT (S (VP (VB Assess) (NP (NP (DT the) (NNS factors)) (SBAR (WHNP (WDT that)) (S (VP (VBP cause) (NP (JJ natural) (NN selection))))))) (. .)))
Assess the factors that cause natural selection.
(ROOT (S (NP (NNP Community) (NNS interactions)) (VP (VBP are) (NP (NP (JJ important) (NNS factors)) (PP (IN in) (NP (JJ natural) (NN selection))))) (. .)))