“In regard to plants, there is another means of observing the
accumulated effects of selection—namely, by comparing the diversity of
flowers in the different varieties of the same species in the
flower-garden; the diversity of leaves, pods, or tubers, or whatever
part is valued, in the kitchen-garden, in comparison with the flowers of
the same varieties; and the diversity of fruit of the same species in
the orchard, in comparison with the leaves and flowers of the same set
of varieties. See how different the leaves of the cabbage are, and how
extremely alike the flowers; how unlike the flowers of the heartsease
are, and how alike the leaves; how much the fruit of the different kinds
of gooseberries differ in size, color, shape, and hairiness, and yet the
flowers present very slight differences. It is not that the varieties
which differ largely in some one point do not differ at all in other
points; this is hardly ever,—I speak after careful observation,—perhaps
never, the case. The law of correlated variation, the importance of
which should never be overlooked, will insure some differences; but, as
a general rule, it cannot be doubted that the continued selection of
slight variations, either in the leaves, the flowers, or the fruit, will
produce races differing from each other chiefly in these characters.”
Exception may perhaps be taken to the concluding sentence, for,
interesting as the facts here recorded certainly are, it does not
necessarily follow that all domestic products have arisen “by the
continued selection of slight variations,” however probable the
conclusion may appear. Darwin also believes that a process of
“unconscious selection” has given even more important “results than
methodical selection.” By unconscious selection is meant the outcome of
“every one trying to possess and breed from best individual animals.”
“Thus a man who intends keeping pointers naturally tries to get as good
dogs as he can, and afterwards breeds from his own best dogs, but he has
no wish, or expectation of permanently altering the breed. Nevertheless
we may infer that this process, continued during centuries, would
improve and modify any breed.... There is reason to believe that the
King Charles spaniel has been unconsciously modified to a large extent
since the time of that monarch.”
Public-domain text, read in full here on John Shaqi.
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