Origin of Species Variorum

Comparison with 1866

As we sometimes see individuals of a species following habits widely different from those of their own species and of the other species of the same genus, we might expect, on my theory, that such individuals would occasionally have given rise to new species, having anomalous habits, and with their structure either slightly or considerably modified from that of their proper type. And such instances do occur in nature. Can a more striking instance of adaptation be given than that of a woodpecker for climbing trees and for seizing insects in the chinks of the bark? Yet in North America there are woodpeckers which feed largely on fruit, and others with elongated wings which chase insects on the wing. On the plains of La Plata, where not a tree grows, there is a woodpecker ( Colaptes campestris ) which has two toes before and two behind, a long pointed tongue, stiff pointed tail-feathers, but not so stiff as in the typical woodpeckers (yet I have seen it use its tail when alighting vertically on a post), and a straight strong beak. The beak, however, is not so straight or strong as in the typical woodpeckers; but it is strong enough to bore into wood; and I may mention, as another illustration of the varied habits of the tribe, that a Mexican Colaptes has been described by De Saussure as boring holes into hard wood in order to lay up a store of acorns for its future consumption! Hence the Colaptes of La Plata in all the essential parts of its organization is a woodpecker, and until recently was classed in the same typical genus. Even such trifling characters as its colouring, the harsh tone of its voice, and undulatory flight, all told me plainly of its close blood-relationship to our common species; yet it is a woodpecker, as I can assert not only from my own observation, but from that of the accurate Azara, which never climbs a tree! ↑

Petrels are the most aërial and oceanic of birds, but in the quiet Sounds of Tierra del Fuego, the Puffinuria

seen climbing branches, almost like a creeper; it often, like a shrike, kills small birds by blows on the head; and I have many times seen and heard it hammering the seeds of the yew on a branch, and thus breaking them like a nuthatch. In North America the black bear was seen by Hearne swimming for hours with widely open mouth, thus catching, like a whale, insects in the water. Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.

As we sometimes see individuals of a species following habits widely different from those both of their own species and of the other species of the same genus, we might expect, on my theory, that such individuals would occasionally have given rise to new species, having anomalous habits, and with their structure either slightly or considerably modified from that of their proper type. And such instances do occur in nature. Can a more striking instance of adaptation be given than that of a woodpecker for climbing trees and for seizing insects in the chinks of the bark? Yet in North America there are woodpeckers which feed largely on fruit, and others with elongated wings which chase insects on the wing; and on the plains of La Plata, where not a tree grows, there is a woodpecker, which in every essential part of its organisation, even in its colouring, in the harsh tone of its voice, and undulatory flight, told me plainly of its close blood-relationship to our common species; yet it is a woodpecker which never climbs a tree! ↑ ↑

Petrels are the most aërial and oceanic of birds, yet in the quiet Sounds of Tierra del Fuego, the Puffinuria