A bird does not fly because it has wings; it has wings because it flies.
The Territorial Imperative
The statement feels like the inverse of the logical or backward reasoning. My immediate response is of course the bird flies because it has wings. However the statement strikes a similar chord with me and my argument for the left tongue. The age old question does function dictate structure or vice versa . I have a left tongue in it's wiring but I perceive it as one tongue with a right and left side. I do not sense a left tongue and a right tongue co-joined. I see the other persona as existing in their right side of head and I respond to it with my right side. My right eye crosses my midline to their right eye. I know the left eye is there on my periphery but I do not engage it nor does my left half of face initiate emotion in concurrence or opposition with their left half of face. The initiation of movement is a prerogative of my right side of head. I feel my brain lateralization of speech/communication is enhanced by my perception of others and the need for efficiency instead of the brain lateralization existing solely a priori.
."It is the chaffinch, however, that provides an illuminating example of the open instinct. In Denmark the chaffinch begins to sing about February 15. Poulsen raised males in isolation. By the middle of January they were beginning to twitter and in two weeks were producing an abbreviated chaffinch song, imperfect of pitch, imperfect of rhythm.  When Chaffinch Day came in the middle of February, he freed them but allowed them at first to mix only with linnets. They imitated the linnet and succeeded in producing some of its notes. But then they heard a chaffinch. Immediately they perfected their chaffinch song, nor did they imitate the linnet ever again."