The Origin of Species by Means of Natural Selection: Or, the Preservation of Favoured Races in the Struggle for Life, 6th EditionDarwin, Charles
History
The Origin of Species by Means of Natural Selection: Or, the Preservation of Favoured Races in the Struggle for Life, 6th Edition
Darwin, Charles
Evolution (Biology); Natural selection
Youatt gives an excellent illustration of the effects of a course of
selection which may be considered as unconscious, in so far that the
breeders could never have expected, or even wished, to produce the
result which ensued—namely, the production of the distinct strains. The
two flocks of Leicester sheep kept by Mr. Buckley and Mr. Burgess, as
Mr. Youatt remarks, “Have been purely bred from the original stock of
Mr. Bakewell for upwards of fifty years. There is not a suspicion
existing in the mind of any one at all acquainted with the subject that
the owner of either of them has deviated in any one instance from the
pure blood of Mr. Bakewell’s flock, and yet the difference between the
sheep possessed by these two gentlemen is so great that they have the
appearance of being quite different varieties.”
If there exist savages so barbarous as never to think of the inherited
character of the offspring of their domestic animals, yet any one
animal particularly useful to them, for any special purpose, would be
carefully preserved during famines and other accidents, to which
savages are so liable, and such choice animals would thus generally
leave more offspring than the inferior ones; so that in this case there
would be a kind of unconscious selection going on. We see the value set
on animals even by the barbarians of Tierra del Fuego, by their killing
and devouring their old women, in times of dearth, as of less value
than their dogs.
In plants the same gradual process of improvement through the
occasional preservation of the best individuals, whether or not
sufficiently distinct to be ranked at their first appearance as
distinct varieties, and whether or not two or more species or races
have become blended together by crossing, may plainly be recognised in
the increased size and beauty which we now see in the varieties of the
heartsease, rose, pelargonium, dahlia, and other plants, when compared
with the older varieties or with their parent-stocks. No one would ever
expect to get a first-rate heartsease or dahlia from the seed of a wild
plant. No one would expect to raise a first-rate melting pear from the
seed of a wild pear, though he might succeed from a poor seedling
growing wild, if it had come from a garden-stock. The pear, though
cultivated in classical times, appears, from Pliny’s description, to
have been a fruit of very inferior quality. I have seen great surprise
expressed in horticultural works at the wonderful skill of gardeners in
having produced such splendid results from such poor materials; but the
art has been simple, and, as far as the final result is concerned, has
been followed almost unconsciously. It has consisted in always
cultivating the best known variety, sowing its seeds, and, when a
slightly better variety chanced to appear, selecting it, and so
onwards. But the gardeners of the classical period, who cultivated the
best pears which they could procure, never thought what splendid fruit
Public-domain text, read in full here on John Shaqi.
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