And the cases just given, more especially that of pigeons, seem to show that the characteristic differences which give value to each breed, and which have been And the cases just given, more especially that of pigeons, seem to show that the characteristic differences which give value to each breed, and which have been 1859 1860 1861 |
Fanciers select their horses, dogs, and pigeons, for breeding, when they are nearly grown up: they are indifferent whether the desired qualities and structures have been 1866 |
And the cases just given, more especially that of pigeons, show that the characteristic differences which give value to the breeds and which have been 1869 |
Fanciers select their dogs, horses, pigeons, &c., for breeding, when nearly grown up: they are indifferent whether the desired qualities are 1872 |
accumulated by mans selection, have not generally first appeared at an early period of life, and have been inherited by the offspring at a corresponding not early period. accumulated by mans selection, have not generally first appeared at an early period of life, and have been inherited by the offspring at a corresponding not early period. 1860 |
accumulated by man's selection, have not generally first appeared at an early period of life, and have been inherited by the offspring at a corresponding not early period. 1859 1861 |
acquired earlier or later in life, if the full-grown animal possesses them. 1866 1872 |
accumulated by mans selection, have not generally appeared at a very early period of life, and have been inherited at a corresponding not early period. 1869 |
But But 1859 1860 1861 1869 | And 1866 1872 |
the
case case 1859 1860 1861 1869 | cases 1866 1872 |
of the short-faced tumbler, which when twelve hours old had acquired its proper proportions, proves that this is not the universal rule; for here of the short-faced tumbler, which when twelve hours old had acquired its proper proportions, proves that this is not the universal rule; for here 1859 1860 1861 |
just given, more especially that of pigeons, seem to show that 1866 |
of the short-faced tumbler, which when twelve hours old possessed its proper characters, proves that this is not the universal rule; for here 1869 |
just given, more especially that of the pigeons, show that 1872 |
the characteristic differences
must either have appeared at an earlier period than usual, or, if not so, the differences must must either have appeared at an earlier period than usual, or, if not so, the differences must 1859 1860 1861 1869 |
which give value to each breed, and which 1866 |
which 1872 |
have been
inherited, not at the corresponding, but inherited, not at the corresponding, but 1859 1860 1861 |
accumulated by man's selection, have not generally first appeared 1866 |
inherited, not at a corresponding, but 1869 |
accumulated by man's selection, and which give value to his breeds, do not generally appear 1872 |
at
an an 1859 1860 1861 1866 1869 | a very 1872 |
earlier age. earlier age. 1859 1860 1861 1869 |
early period of life, and have been inherited by the offspring at a corresponding not early period. 1866 |
early period of life, and are inherited at a corresponding not early period. 1872 |
↑1 blocks not present in 1859 1860 1861 1869; present in 1866 1872 | But the case of the short-faced tumbler, which when twelve hours old had acquired
its proper proportions,
proves that this is not the universal rule; for here the characteristic differences must either have appeared at an earlier period than usual, or, if not so, the differences must have been inherited, not at the
corresponding, but at an earlier age.
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|
Now let us apply these
facts and the above two principles— which latter, though not proved true, can be shown to be in some degree probable— facts and the above two principles— which latter, though not proved true, can be shown to be in some degree probable— 1859 1860 1861 |
facts and the above two principles 1866 |
two principles 1869 1872 |
to species in a state of nature. Let us take a
genus genus 1859 1860 1861 1866 | group 1869 1872 |
of birds, descended
on my theory on my theory 1859 1860 1861 1866 |
OMIT 1869 1872 |
from some
one parent-species, and of which the several new species have become one parent-species, and of which the several new species have become 1859 1860 1861 1866 |
ancient form and 1869 1872 |
modified through natural selection
in accordance with their diverse in accordance with their diverse 1859 1860 1861 1866 |
for different 1869 1872 |
habits. Then, from the many slight successive
steps of steps of 1859 1860 1861 1866 | steps of 1869 1872 |
variation variation 1859 1860 1861 1866 | variations 1869 1872 |
having supervened
at a rather late at a rather late 1859 1860 1861 1866 |
in the several species at a not early 1869 1872 |
age, and having been inherited at a corresponding age, the young
of the new species of our supposed genus will manifestly tend to of the new species of our supposed genus will manifestly tend to 1859 1860 1861 1866 |
will be left but little modified and will 1869 |
will have been but little modified, and they will still 1872 |
resemble each other much more closely than do the
adults, adults, 1859 1860 1861 1866 | adults,— 1869 1872 |
just as we have seen
in in 1859 1860 1861 1866 | with 1869 1872 |
the
case case 1859 1860 1861 1866 | breeds 1869 1872 |
of
pigeons. pigeons. 1859 1860 1861 1866 | the pigeon. 1869 1872 |
We may extend this view to
whole families or even whole families or even 1859 1860 1861 1866 |
widely distinct structures and to whole 1869 1872 |
classes. The fore-limbs, for instance, which
served served 1859 1860 1861 1866 | once served 1869 1872 |
as legs
in the parent-species, may have become, by in the parent-species, may have become, by 1860 1861 1866 |
in the parent-species, may become, by 1859 |
to a remote progenitor, may have become, through 1869 1872 |
a long course of modification, adapted in one descendant to act as hands, in another as paddles, in another as wings;
and and 1859 1860 1861 1866 | but 1869 1872 |
on the above two
principles— namely of each successive modification supervening at a rather late age, and being inherited at a corre- sponding late age— principles— namely of each successive modification supervening at a rather late age, and being inherited at a corre- sponding late age— 1860 |
principles— namely of each successive modification supervening at a rather late age, and being inherited at a corresponding late age— 1859 1861 1866 |
principles 1869 1872 |
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