Comparison with 1866 |
|
portions of a strictly continuous area, intermediate varieties will, it is probable, at first have been formed in the intermediate zones, but they will generally have had a short duration. For these intermediate varieties will, from reasons already assigned (namely from what we know of the actual distribution of closely allied or representative species, and likewise of acknowledged varieties), exist in the intermediate zones in lesser numbers than the varieties which they tend to connect. From this cause alone the interme- diate
varieties will be liable to accidental extermination; and during the process of further modification through natural selection, they will almost certainly be beaten and supplanted by the forms which they connect; for these from existing in greater numbers will, in the aggregate, present more
variation, variation, 1859 1860 1861 1866 1869 | varieties, 1872 |
and thus be further improved through natural selection and gain further advantages. |
|
Lastly, looking not to any one time, but to all time, if my theory be true, numberless intermediate varieties, linking most
closely all the species of the same group together,
must assuredly have existed; but the very process of natural selection constantly tends, as has been so often remarked, to exterminate the parent forms
and the intermediate links. Consequently evidence of their former existence could be found only amongst fossil remains, which are preserved, as we shall
in a future chapter attempt to show, in in a future chapter attempt to show, in 1859 1860 1861 1866 1869 |
attempt to show in a future chapter, in 1872 |
an extremely imperfect and intermittent record. |
On
On
1866 1869 |
On
1859 1860 1861 1872 |
the
the
1866 1869 |
the
1859 1860 1861 1872 |
Origin
Origin
1866 1869 |
origin
1859 1860 1861 |
Origin
1872 |
and
and
1866 1869 |
and
1859 1860 1861 1872 |
Transitions
Transitions
1866 1869 |
transitions
1859 1860 1861 |
Transitions
1872 |
of
of
1866 1869 |
of
1859 1860 1861 1872 |
Organic
Organic
1866 1869 |
organic
1859 1860 1861 |
Organic
1872 |
Beings
Beings
1866 1869 |
beings
1859 1860 1861 |
Beings
1872 |
with
with
1866 1869 |
with
1859 1860 1861 1872 |
peculiar
peculiar
1866 1869 |
peculiar
1859 1860 1861 1872 |
Habits
Habits
1866 1869 |
habits
1859 1860 1861 |
Habits
1872 |
and
and
1866 1869 |
and
1859 1860 1861 1872 |
Structure
.
Structure
. 1866 |
structure
.—
1859 1861 |
structure.
—
1860 |
Structure. 1869 |
Structure
.—
1872 |
|
It has been asked by the opponents of such views as I hold, how, for instance,
a land carnivorous animal could a land carnivorous animal could 1859 1860 1861 1866 1869 |
could a land carnivorous animal 1872 |
have been converted into one with aquatic habits; for how could the animal in its transitional state have subsisted? It would be easy to show that
within the same group within the same group 1859 1860 1861 1866 1869 |
there now exist 1872 |
carnivorous animals
exist, having every exist, having every 1866 1869 |
exist having every 1859 1860 1861 |
presenting close 1872 |
intermediate
grade grade 1859 1860 1861 1866 1869 | grades 1872 |
between truly aquatic and between truly aquatic and 1859 1860 1861 1866 1869 |
from 1872 |
strictly terrestrial
habits; habits; 1859 1860 1861 1866 1869 |
to aquatic habits; 1872 |
and as each exists by a struggle for life, it is clear that each
is is 1859 1860 1861 1866 1869 | must be 1872 |
well adapted
in in 1859 1860 1861 1866 1869 | to 1872 |
its
habits to its habits to its 1859 1860 1861 1866 1869 |
OMIT 1872 |
place in nature. Look at the Mustela vison of North America, which has webbed feet
and which resembles an otter in its fur, short legs, and form of
tail; tail; 1859 1860 1861 1866 1869 | tail. 1872 |
during during 1859 1860 1861 1866 1869 | during 1872 |
summer summer 1859 1860 1861 1866 1869 | summer 1872 |
this this 1859 1860 1861 1866 1869 | this 1872 |
animal animal 1859 1860 1861 1866 1869 | animal 1872 |
dives dives 1859 1860 1861 1866 1869 | dives 1872 |
for for 1859 1860 1861 1866 1869 | for 1872 |
and and 1859 1860 1861 1866 1869 | and 1872 |
preys preys 1859 1860 1861 1866 1869 | preys 1872 |
on on 1859 1860 1861 1866 1869 | on 1872 |
fish, fish, 1859 1860 1861 1866 1869 | fish, 1872 |
but but 1859 1860 1861 1866 1869 | but 1872 |
during during 1859 1860 1861 1866 1869 | during 1872 |
the the 1859 1860 1861 1866 1869 | the 1872 |
long long 1859 1860 1861 1866 1869 | long 1872 |
winter winter 1859 1860 1861 1866 1869 | winter 1872 |
it it 1859 1860 1861 1866 1869 | it 1872 |
leaves leaves 1859 1860 1861 1866 1869 | leaves 1872 |
the the 1859 1860 1861 1866 1869 | the 1872 |
frozen frozen 1859 1860 1861 1866 1869 | frozen 1872 |
waters, waters, 1859 1860 1861 1866 1869 | waters, 1872 |
and and 1859 1860 1861 1866 1869 | and 1872 |
preys, preys, 1866 1869 | preys 1859 1860 1861 | preys, 1872 |
like like 1859 1860 1861 1866 1869 | like 1872 |
other other 1859 1860 1861 1866 1869 | other 1872 |
pole-cats, pole-cats, 1866 1869 | polecats 1859 1860 | pole-cats 1861 | pole-cats, 1872 |
on on 1859 1860 1861 1866 1869 | on 1872 |
mice mice 1859 1860 1861 1866 1869 | mice 1872 |
and and 1859 1860 1861 1866 1869 | and 1872 |
land land 1859 1860 1861 1866 1869 | land 1872 |
animals. animals. 1859 1860 1861 1866 1869 | animals. 1872 |
If a different case had been taken, and it had been asked how an insectivorous quadruped could possibly have been converted into a flying bat, the question would have been far more difficult to answer. If a different case had been taken, and it had been asked how an insectivorous quadruped could possibly have been converted into a flying bat, the question would have been far more difficult to answer. 1866 1869 |
If a different case had been taken, and it had been asked how an insectivorous quadruped could possibly have been converted into a flying bat, the question would have been far more difficult, and I could have given no answer. 1859 1860 1861 |
During the summer this animal dives for and preys on fish, but during the long winter it leaves the frozen waters, and preys, like other pole-cats, on mice and land animals. 1872 |
Yet Yet 1859 1860 1861 1866 1869 |
If a different case had been taken, and it had been asked how an insectivorous quadruped could possibly have been converted into a flying bat, the question would have been far more difficult to answer. Yet 1872 |
I think such difficulties have very
little weight. |
|
Here, as on other occasions, I lie under a heavy disadvantage, for
out of the many striking cases which I have collected, I can give only one or two instances of transitional habits and structures in
|