( Darwin ( ( discussed ( ( many examples ) ( of ( ( ( artificial selection ) , ) ( ( in which ) ( humans ( have ( ( modified species ) ( through ( ( selection and ) breeding ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Darwin)) (VP (VBD discussed) (NP (NP (JJ many) (NNS examples)) (PP (IN of) (NP (NP (JJ artificial) (NN selection)) (, ,) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (NNS humans)) (VP (VBP have) (VP (VBN modified) (NP (NNS species)) (PP (IN through) (NP (NN selection) (CC and) (NN breeding))))))))))) (. .)))
Darwin discussed many examples of artificial selection, in which humans have modified species through selection and breeding.
(ROOT (S (NP (NNS Humans)) (VP (VBP create) (NP (NP (JJ different) (NNS breeds)) (PP (IN of) (NP (NP (NNS organisms)) (VP (VBG using) (NP (JJ artificial) (NN selection))))))) (. .)))