have well remarked, by man; he can neither originate varieties, nor prevent their occurrence; he can only preserve and accumulate such as do
occur; occur; 1861 1866 1869 | occur. 1872 |
unintentionally unintentionally 1861 1866 1869 | unintentionally 1872 |
he
exposes exposes 1861 1866 1869 | exposes 1872 |
organic organic 1861 1866 1869 | organic 1872 |
beings beings 1861 1866 1869 | beings 1872 |
to
new new 1861 1866 1869 | new 1872 |
and and 1861 1866 1869 | and 1872 |
changing changing 1861 1866 1869 | changing 1872 |
conditions conditions 1861 1866 1869 | conditions 1872 |
of
life, life, 1861 1866 1869 | life, 1872 |
and and 1861 1866 1869 | and 1872 |
variability variability 1861 1866 1869 | variability 1872 |
ensues; ensues; 1861 1866 1869 | ensues; 1872 |
but but 1861 1866 1869 | but 1872 |
similar similar 1861 1866 1869 | similar 1872 |
changes changes 1861 1866 1869 | changes 1872 |
of
conditions conditions 1861 1866 1869 | conditions 1872 |
might might 1861 1866 1869 | might 1872 |
and and 1861 1866 1869 | and 1872 |
do
occur occur 1861 1866 1869 | occur 1872 |
under under 1861 1866 1869 | under 1872 |
nature. nature. 1861 1866 1869 | nature. 1872 |
↑1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | Unintentionally he exposes organic beings to new and changing conditions of life, and variability ensues; but similar changes of conditions might and do occur under nature.
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Let it
also be also be 1861 1866 1869 1872 | be 1859 1860 |
borne in mind how infinitely complex and
close-fitting close-fitting 1859 1860 1861 1869 1872 | closefitting 1866 |
are the mutual relations of all organic beings to each other and to their physical conditions of
life; life; 1861 1866 1869 1872 | life. 1859 1860 |
and consequently what infinitely varied diversities of structure
may may 1861 1866 1869 | might 1872 |
be of use to each being under changing conditions of life. Can it, then, be thought improbable, seeing that variations useful to man have undoubtedly occurred, that other variations useful in some way to each being in the great and complex battle of life, should
sometimes sometimes 1859 1860 1861 1866 1869 | sometimes 1872 |
occur in the course of
thousands of thousands of 1859 1860 1861 1866 1869 | many successive 1872 |
generations? If such do occur, can we doubt
(remembering (remembering 1861 1866 1869 1872 | (remem- bering 1859 1860 |
that many more individuals are born than can possibly survive) that individuals having any advantage, however slight, over others, would have the best chance of surviving and of procreating their kind? On the other hand, we may feel sure that any variation in the least degree injurious would be rigidly destroyed. This preservation of favourable
variations, variations, 1866 1869 |
variations 1859 1860 1861 |
individual differences and variations, 1872 |
and the
destruction destruction 1869 1872 | rejection 1859 1860 1861 1866 |
of
injurious variations, I call injurious variations, I call 1859 1860 1861 1866 1869 |
those which are injurious, I have called 1872 |
Natural
Selection, or the Survival of the Fittest. Selection, or the Survival of the Fittest. 1869 1872 |
Selection. 1859 1860 1861 1866 |
Variations neither useful nor injurious would not be affected by natural selection, and would be left
either a either a 1869 1872 | a 1859 1860 1861 1866 |
fluctuating element, as perhaps we see in
certain polymorphic species, or would ultimately become fixed, owing to the nature of the organism and the nature of the conditions. certain polymorphic species, or would ultimately become fixed, owing to the nature of the organism and the nature of the conditions. 1869 1872 |
the species called polymorphic. 1859 1860 1861 1866 |
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