Comparison with 1859 |
|
selection, even if we looked
no
further further 1859 1860 | farther 1861 1866 1869 1872 |
than this, seems to me to
be in itself
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
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
number of varieties or incipient species, retain to a certain degree the character of varieties; for they differ from each other by a less amount of difference than do the species of smaller genera. The closely allied species also of the larger genera apparently have restricted ranges, and
they they 1859 |
in their affinities they 1860 1861 1866 1869 1872 |
are clustered in little groups round other species— in which
respects they
resemble
varieties. These are strange relations on the view of
each species having been
independently created, but are intelligible if all species first existed as
varieties.
|
|
As each species tends by its geometrical ratio
of reproduction to increase inordinately in number; and as the modified descendants of each species will be enabled to increase by so
much the more
as they
|
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 varieties or incipient species, retain to a certain degree the character of varieties; for they differ from each other by a less amount of difference than do the species of smaller genera. The closely allied species also of the larger genera apparently have restricted ranges, and
in their affinities they in their affinities they 1860 1861 1866 1869 1872 |
they 1859 |
are clustered in little groups round other species— in
which which 1859 1860 1861 |
both of which 1866 1869 |
both 1872 |
respects
they they 1859 1860 1861 1866 1869 | they 1872 |
resemble resemble 1859 1860 1861 1866 1869 | resembling 1872 |
varieties. These are strange relations on the view
of of 1859 1860 1861 | that 1866 1869 1872 |
each species
having been having been 1859 1860 1861 | was 1866 1869 1872 |
independently created, but are intelligible if
all species first existed as all species first existed as 1859 1860 1861 |
each existed first as a 1866 1869 1872 |
varieties. varieties. 1859 1860 1861 | variety. 1866 1869 1872 |
|
|
As each species tends by its geometrical
ratio ratio 1859 1860 1861 1866 1869 | rate 1872 |
of reproduction to increase inordinately in number; and as the modified descendants of each species will be enabled to increase by
so so 1859 1860 1861 1866 1869 | as 1872 |
much
the more the more 1859 1860 1861 1866 1869 | the more 1872 |
as they
|