Comparison with 1859 |
|
species. Consequently the groups which are now large, and which generally include many dominant species, tend to go on increasing indefinitely
in size. I further attempted to show that from the varying descendants of each species trying to occupy as many and as different places as possible in the economy of nature, there is a constant tendency in their characters
to diverge. This conclusion was
supported by looking at
the great diversity of the
forms of life
which, in any small area, come into the closest competition, and by looking to
certain facts in naturalisation. |
|
I attempted also to show that there is a constant
tendency in the forms which are increasing in number and diverging in character, to supplant and exterminate the less divergent, the
less improved,
and preceding
forms. I request the reader to turn to the diagram illustrating the action, as formerly explained, of these several principles; and he will see that the inevitable result is
that the modified descendants proceeding from one progenitor become broken up into groups subordinate to groups. In the diagram each letter on the uppermost line may represent a genus including several species; and all
the genera on this
line
form together one class, for all have
descended from one ancient but unseen
parent,
and, consequently, have inherited something in common. But the three genera on the left hand have, on this same principle, much in common, and form a sub-family, distinct from that including
the next two genera on the right hand, which diverged from a common parent at the fifth stage of descent. These five genera have also much,
though less, in common;
and they form a family distinct from that including
the three genera still further
to the right hand, which diverged at a still
earlier period. And all these genera, descended
from (A), form an order distinct from the
|
species. Consequently the groups which are now large, and which generally include many dominant species, tend to go on increasing
indefinitely indefinitely 1859 1860 | indefinitely 1861 1866 1869 1872 |
in size. I further attempted to show that from the varying descendants of each species trying to occupy as many and as different places as possible in the economy of nature,
there is a constant tendency in their characters there is a constant tendency in their characters 1859 1860 1861 1866 1869 |
they constantly tend 1872 |
to
diverge. diverge. 1859 1860 1861 1866 1869 |
diverge in character. 1872 |
This
conclusion was conclusion was 1859 1860 1861 1866 |
latter conclusion is 1869 1872 |
supported by
looking at looking at 1859 1860 1861 1866 | observing 1869 1872 |
the great diversity of
the the 1859 1860 1861 1866 | the 1869 1872 |
forms
of life of life 1859 1860 1861 1866 | of life 1869 1872 |
which, in any small area, come into the closest competition, and by
looking to looking to 1859 1860 1861 1866 | looking to 1869 1872 |
certain facts in naturalisation. |
|
I attempted also to show that there is a
constant constant 1859 1860 1861 1866 1869 | steady 1872 |
tendency in the forms which are increasing in number and diverging in character, to supplant and exterminate the
less divergent, the less divergent, the 1859 1860 1861 |
preceding, less divergent and 1866 1869 1872 |
less
improved, improved, 1859 1860 1861 | improved 1866 1869 1872 |
and preceding and preceding 1859 1860 1861 | and preceding 1866 1869 1872 |
forms. I request the reader to turn to the diagram illustrating the action, as formerly explained, of these several principles; and he will see that the inevitable result
is is 1859 1860 1861 1866 1869 | is, 1872 |
that the modified descendants proceeding from one progenitor become broken up into groups subordinate to groups. In the diagram each letter on the uppermost line may represent a genus including several species; and
all all 1859 1860 1861 1866 | all 1869 1872 |
the
genera on this genera on this 1859 1860 1861 1866 |
whole of the genera along this upper 1869 1872 |
line line 1859 1860 1869 1872 | upper line 1861 1866 |
form together one class, for all
have have 1859 1860 1861 1866 | are 1869 1872 |
descended from one ancient
but unseen but unseen 1859 1860 | but unseen 1861 1866 1869 1872 |
parent, parent, 1859 1860 1861 1866 | parent 1869 1872 |
and, consequently, have inherited something in common. But the three genera on the left hand have, on this same principle, much in common, and form a sub-family, distinct from that
including including 1859 1860 1861 1866 1869 | containing 1872 |
the next two genera on the right hand, which diverged from a common parent at the fifth stage of descent. These five genera have also
much, much, 1859 1860 1861 1866 1869 | much 1872 |
though less, in common; though less, in common; 1859 1860 1861 1866 1869 |
in common, though less than when grouped in sub-families; 1872 |
and they form a family distinct from that
including including 1859 1860 1861 1866 1869 | containing 1872 |
the three genera still
further further 1859 1860 | farther 1861 1866 1869 1872 |
to the right hand, which diverged at
a still a still 1859 1860 1861 1866 1869 | an 1872 |
earlier period. And all these genera,
descended descended 1859 1860 1866 1869 1872 | pescended 1861 |
from (A), form an order distinct from the
|