( ( ( ( ( ( More specialized ) , ) ( sometimes human-made ) ) , ) habitats ) ( ( ( are also ) ( ( often well ) ( populated ( by ( ( both ( ( pigmented and ) nonpigmented ) ) protists ) ) ) ) ) . ) )
(ROOT (S (NP (ADJP (ADJP (RBR More) (JJ specialized)) (, ,) (ADJP (RB sometimes) (JJ human-made)) (, ,)) (NNS habitats)) (VP (VBP are) (ADVP (RB also)) (ADJP (ADVP (RB often) (RB well)) (VBN populated) (PP (IN by) (NP (ADJP (DT both) (JJ pigmented) (CC and) (JJ nonpigmented)) (NNS protists))))) (. .)))
More specialized, sometimes human-made, habitats are also often well populated by both pigmented and nonpigmented protists.
(ROOT (S (NP (JJ Multiple) (NN fission)) (VP (VBZ is) (ADVP (RBR more) (RB often)) (VP (VBN observed) (PP (IN among) (NP (NNS protists))))) (. .)))