. The birds of California : a complete, scientific and popular account of the 580 species and subspecies of birds found in the state. Birds; Birds. The Abert Towhee species concepts is one of the most pernicious influ- ences in science. We can- not avoid it altogether, but we can face it out and persistently discredit it. Thus it is that the mere assignment of names breaks up and artificially spaces out certain groups of bird species whose differ- ences, though constant, are almost infinitesimal; and it contracts and ren- ders inoperative the value- distances which separate certain other speci
. The birds of California : a complete, scientific and popular account of the 580 species and subspecies of birds found in the state. Birds; Birds. The Abert Towhee species concepts is one of the most pernicious influ- ences in science. We can- not avoid it altogether, but we can face it out and persistently discredit it. Thus it is that the mere assignment of names breaks up and artificially spaces out certain groups of bird species whose differ- ences, though constant, are almost infinitesimal; and it contracts and ren- ders inoperative the value- distances which separate certain other species whose names, if we were consist- ent, could not be printed on the same page, or even in the same book. As a practical illus- tration of all this I would cite the case of the genus Pipilo. Regarding for the present only those rep- resentatives of the genus which occur above the Mexican border, and dropping for the moment sub-specific terminations, we have five species to deal with: Pipilo maculatus, P. erythrophthalmus, P. fuscus, P. aberti, and P. crissalis. The mere enumeration of these species names gives each one dignity and value, a place among its fellows. Whatever the facts may be, naming terms coordi- nates them. It gives them equal value to our human apprehension. And though we spend the rest of our lifetime specializing on the genus Pipilo, we shall never be able to shake off this initial presumption that Pipilo aberti is as distinct, as different, as important, as P. maculatus. Yet if we regard evolutionary distance, or what I have called value distance (for evolution proceeds in different stocks at very different rates), we shall find the three members of the Pipilo fuscus-aberti-crissalis group, the Brown Towhees, as close together as three contiguous Earths; while the members of the Pipilo maculatus group would figure as a constellation of Neptunes. In other words, a printed list of the names of members of the genus Pipilo is as inexpressive of the value distanc
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, bookyear1923
