( ( Although ( ( cerana bees ) ( must ( have ( ( shared ( a ( common ancestor ) ) ) ( with mellifera ) ) ) ) ) ) ( , ( they ( ( have ( evolved ( into ( separate species ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (NN cerana) (NNS bees)) (VP (MD must) (VP (VB have) (VP (VBN shared) (NP (DT a) (JJ common) (NN ancestor)) (PP (IN with) (NP (NN mellifera)))))))) (, ,) (NP (PRP they)) (VP (VBP have) (VP (VBN evolved) (PP (IN into) (NP (JJ separate) (NNS species))))) (. .)))
Although cerana bees must have shared a common ancestor with mellifera, they have evolved into separate species.
(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.