( Experts ( ( believe ( that ( ( much ( of ( this increase ) ) ) ( is ( due ( to ( ( ( ( ( ( people 's ) ( greater exposure ) ) to ) ( ( the ( sun 's ) ) ( ultraviolet radiation ) ) ) , ) ( which ( can ( ( ( ( ( cause misspellings ) ( in DNA ) ) and ) ( , ( ( as ( a result ) ) , ) ) ) ( damage ( skin cells ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Experts)) (VP (VBP believe) (SBAR (IN that) (S (NP (NP (RB much)) (PP (IN of) (NP (DT this) (NN increase)))) (VP (VBZ is) (ADJP (JJ due) (PP (TO to) (NP (NP (NP (NP (NNS people) (POS 's)) (JJR greater) (NN exposure)) (TO to) (NP (NP (DT the) (NN sun) (POS 's)) (JJ ultraviolet) (NN radiation))) (, ,) (SBAR (WHNP (WDT which)) (S (VP (MD can) (VP (VP (VB cause) (NP (NNS misspellings)) (PP (IN in) (NP (NNP DNA)))) (CC and) (PRN (, ,) (PP (IN as) (NP (DT a) (NN result))) (, ,)) (VP (VB damage) (NP (NN skin) (NNS cells)))))))))))))) (. .)))
Experts believe that much of this increase is due to people's greater exposure to the sun's ultraviolet radiation, which can cause misspellings in DNA and, as a result, damage skin cells.
(ROOT (S (NP (NP (NNP Exposure)) (PP (TO to) (NP (JJ ultraviolet) (NN radiation)))) (VP (MD can) (VP (VP (VB increase) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NN pigment)))) (PP (IN in) (NP (DT the) (NN skin)))) (CC and) (VP (VB make) (S (NP (PRP it)) (VP (VB appear) (NP (JJR darker))))))) (. .)))