of the same species come in all respects into the closest competition with each other, the struggle will generally be most severe between them; it will be almost equally severe between the varieties of the same species, and next in severity between the species of the same genus.
But But 1859 1860 1861 1866 | On 1869 1872 |
the
struggle struggle 1859 1860 1861 1866 |
other hand the struggle 1869 1872 |
will often be
very very 1859 1860 1861 1866 1869 | very 1872 |
severe between
beings beings 1859 1860 1861 1869 1872 | being 1866 |
most most 1859 1860 1861 1866 | most 1869 1872 |
remote in the scale of nature. The slightest advantage in
one being, one being, 1859 1860 1861 1866 | certain individuals, 1869 1872 |
at any age or during any season, over those with which
it it 1859 1860 1861 1866 | they 1869 1872 |
comes comes 1859 1860 1861 1866 | come 1869 1872 |
into competition, or better adaptation in however slight a degree to the surrounding physical conditions,
will will 1859 1860 1861 1866 1869 | will, 1872 |
turn turn 1859 1860 1861 1866 1869 | in 1872 |
the
balance. balance. 1859 1860 1861 1866 1869 |
long run, turn the balance. 1872 |
|
|
With animals having separated
sexes sexes 1859 1860 1861 1866 1869 | sexes, 1872 |
there will
in most cases be in most cases be 1859 1860 1861 1866 |
be in most cases 1869 1872 |
a struggle between the males for
possession possession 1859 1860 1861 | the possession 1866 1869 1872 |
of the females. The most vigorous
individuals, individuals, 1859 1860 1861 | males, 1866 1869 1872 |
or those which have most successfully struggled with their conditions of life, will generally leave most progeny. But success will often depend on
having having 1859 1860 1861 |
the males having 1866 1869 1872 |
special
weapons weapons 1859 1860 1861 1866 | weapons, 1869 1872 |
or means of defence, or
on the charms of the males; and the slightest on the charms of the males; and the slightest 1859 1860 1861 |
on their charms; and the slighest 1866 |
charms; and a slight 1869 1872 |
advantage will lead to victory. |
|
As geology plainly proclaims that each land has undergone great physical changes, we might have expected
that that 1859 1860 1861 1866 |
to find that 1869 1872 |
organic beings
would would 1859 1860 1861 1866 | would 1869 1872 |
have varied under nature, in the same way as they
generally generally 1859 1860 1861 1866 | generally 1869 1872 |
have varied under
the changed conditions of the changed conditions of 1859 1860 1861 1866 |
OMIT 1869 1872 |
domestication. And if there
be be 1859 1860 1861 1866 1869 | has been 1872 |
any variability under nature, it would be an unaccountable fact if natural selection
had had 1859 1860 1861 1866 1872 | did 1869 |
not come into play. It has often been asserted, but the assertion is
quite quite 1859 1860 1861 1866 | quite 1869 1872 |
incapable of proof, that the amount of variation under nature is a strictly limited quantity. Man, though acting on external characters alone and often capriciously, can produce within a short period a great result by adding up mere individual differences in his domestic productions; and every one admits that
there are at least there are at least 1859 1860 1861 1866 |
species present 1869 1872 |
individual
differences differences 1859 1860 1861 1866 | differences. 1869 1872 |
in in 1859 1860 1861 1866 | in 1869 1872 |
species species 1859 1860 1861 1866 | species 1869 1872 |
under under 1859 1860 1861 1866 | under 1869 1872 |
nature. nature. 1859 1860 1861 1866 | nature. 1869 1872 |
But, besides such differences, all naturalists
|