why should
we doubt that the variations or individual differences, which are we doubt that the variations or individual differences, which are 1869 |
we doubt that variations 1859 1860 1861 1866 |
not variations or individual differences, which are 1872 |
in
any any 1859 1860 1861 1869 1872 | some 1866 |
way
beneficial would beneficial would 1869 |
useful to beings, under their excessively complex relations of life, would 1859 1860 1861 |
useful to them under their extremely complex relations of life would 1866 |
beneficial, 1872 |
be preserved and accumulated through natural selection, or the survival of the fittest? be preserved and accumulated through natural selection, or the survival of the fittest? 1869 1872 |
be preserved, accumulated, and inherited? 1859 1860 1861 |
occasionally occur, and then be preserved and accumulated by natural selection? 1866 |
If If 1869 1872 | Why, if 1859 1860 1861 1866 |
man can by patience select variations
....... 1869 1872 | most 1859 1860 1861 1866 |
useful to
him, why, him, why, 1869 1872 |
himself, should nature fail in selecting variations useful, 1859 1860 1861 |
himself, should nature fail in preserving or selecting variations useful, 1866 |
under changing
and complex conditions and complex conditions 1869 1872 |
conditions 1859 1860 1861 1866 |
of life,
should not variations useful to natures should not variations useful to natures 1869 |
to her 1859 1860 1861 1866 |
should not variations useful to nature's 1872 |
living
products often arise, and be preserved or selected? products often arise, and be preserved or selected? 1869 1872 |
products? 1859 1860 1861 1866 |
What limit can be put to this power, acting during long ages and rigidly scrutinising the whole constitution, structure, and habits of each creature,— favouring the good and rejecting the bad? I can see no limit to this power, in slowly and beautifully adapting each form to the most complex relations of life. The theory of natural selection, even if we
looked looked 1859 1860 1861 1866 1869 | look 1872 |
no
farther farther 1861 1866 1869 1872 | further 1859 1860 |
than this, seems to
me to me to 1859 1860 1861 1866 1869 | me to 1872 |
be in
itself itself 1859 1860 1861 1866 1869 |
the highest degree 1872 |
probable. I have already recapitulated, as fairly as I could, the opposed difficulties and objections: now let us turn to the special facts and arguments in favour of the theory. |
On the view that species are only strongly marked and permanent varieties, and that each species first existed as a variety, we can see why it is that no line of demarcation can be drawn between species, commonly supposed to have been produced by special acts of creation, and varieties which are acknowledged to have been produced by secondary laws. On this same view we can understand how it is that in
each each 1859 1860 1861 1866 1869 | a 1872 |
region where many species of a genus have been produced, and where they now flourish, these same species should present many varieties; for where the manufactory of species has been active, we might expect, as a general rule, to find it still in action; and this is the case if varieties be incipient species. Moreover, the species of the larger genera, which afford the
greater greater 1859 1860 1861 1869 1872 | great 1866 |
number of
|