( ( Species ( resolved ( in ( this clade ) ) ) ) ( ( appear ( to ( have ( ( ( evolved and ) speciated ) ( from ( ( a ( common ancestor ) ) ( in ( ( the ecosystems ) ( of ( western ( North America ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Species)) (VP (VBN resolved) (PP (IN in) (NP (DT this) (NN clade))))) (VP (VBP appear) (S (VP (TO to) (VP (VB have) (VP (VBN evolved) (CC and) (VBN speciated) (PP (IN from) (NP (NP (DT a) (JJ common) (NN ancestor)) (PP (IN in) (NP (NP (DT the) (NNS ecosystems)) (PP (IN of) (NP (JJ western) (NNP North) (NNP America)))))))))))) (. .)))
Species resolved in this clade appear to have evolved and speciated from a common ancestor in the ecosystems of western North America.
(ROOT (S (NP (NP (DT The) (NN conclusion)) (SBAR (IN that) (S (NP (CD two) (NN animal) (NNS species)) (VP (VBD evolved) (PP (IN from) (NP (DT a) (JJ common) (NN ancestor))) (PP (IN in) (NP (JJ recent) (JJ geological) (NN history))))))) (VP (VBZ is) (ADVP (RBS best)) (VP (VBN supported) (PP (IN by) (NP (DT the) (NN observation))) (SBAR (IN that) (S (NP (DT the) (NNS species)) (VP (VBP have) (NP (JJ similar) (NN bone) (NN structure))))))) (. .)))
The conclusion that two animal species evolved from a common ancestor in recent geological history is best supported by the observation that the species have similar bone structure.