Comparison with 1859 |
|
and
therefore these same characters would be more likely still
to be variable
than the generic characters which have been inherited without change for an enormous
period. It is inexplicable on the theory of creation why a part developed in a very unusual manner in any
one species of
a genus, and therefore, as we may naturally infer, of great importance to the
species, should be eminently liable to variation; but, on my
view, this part has undergone,
since the several species branched off from a common progenitor, an unusual amount of variability and modification, and therefore we might expect this
part generally to be still variable. But a part may be developed in the most unusual manner, like the wing of a bat, and yet not be more variable than any other structure, if the part be common to many subordinate forms, that is, if it has been inherited for a very long period; for in this case it will have been rendered constant by long-continued natural selection. |
|
Glancing at instincts, marvellous as some are, they offer no greater difficulty than does
corporeal structure
on the theory of the natural selection of successive, slight, but profitable modifications. We can thus understand why nature moves by graduated steps in endowing different animals of the same class with their several instincts. I have attempted to show how much light the principle of gradation
throws on the admirable architectural powers of the hive-bee. Habit no doubt sometimes
comes into play in modifying instincts; but it certainly is not indispensable, as we see,
in the case of neuter insects, which leave no progeny to inherit the effects of long-continued habit. On the view of all the species of the same genus having descended from a common parent, and having inherited much in common, we can understand how it is that allied species, when placed under considerably
different conditions of life,
|
and and 1859 1860 1861 1866 | and 1869 1872 |
therefore these same characters would be more likely
still still 1859 1860 1861 1866 | again 1869 1872 |
to
be variable be variable 1859 1860 1861 1866 | vary 1869 1872 |
than the generic characters which have been inherited without change for an
enormous enormous 1859 1860 1861 1866 1869 | immense 1872 |
period. It is inexplicable on the theory of creation why a part developed in a very unusual manner in
any any 1859 1860 1861 1866 1869 | any 1872 |
one species
of of 1859 1860 1861 1866 1869 | alone of 1872 |
a genus, and therefore, as we may naturally infer, of great importance to
the the 1859 1860 1861 | that 1866 1869 1872 |
species, should be eminently liable to variation; but, on
my my 1859 1860 1861 1866 | our 1869 1872 |
view, this part has
undergone, undergone, 1859 1860 1861 1866 1872 | undergone 1869 |
since the several species branched off from a common progenitor, an unusual amount of variability and modification, and therefore we might expect
this this 1859 1860 1861 | the 1866 1869 1872 |
part generally to be still variable. But a part may be developed in the most unusual manner, like the wing of a bat, and yet not be more variable than any other structure, if the part be common to many subordinate forms, that is, if it has been inherited for a very long period; for in this case it will have been rendered constant by long-continued natural selection. |
|
Glancing at instincts, marvellous as some are, they offer no greater difficulty than
does does 1859 1860 1861 1866 1869 | do 1872 |
corporeal
structure structure 1859 1860 1861 1866 1869 | structures 1872 |
on the theory of the natural selection of successive, slight, but profitable modifications. We can thus understand why nature moves by graduated steps in endowing different animals of the same class with their several instincts. I have attempted to show how much light the principle of
gradation gradation 1859 1860 1861 1869 1872 | graduation 1866 |
throws on the admirable architectural powers of the hive-bee. Habit no doubt
sometimes sometimes 1859 1860 1861 1866 1869 | often 1872 |
comes into play in modifying instincts; but it certainly is not indispensable, as we
see, see, 1859 1860 1861 1866 | see 1869 1872 |
in the case of neuter insects, which leave no progeny to inherit the effects of long-continued habit. On the view of all the species of the same genus having descended from a common parent, and having inherited much in common, we can understand how it is that allied species, when placed under
considerably considerably 1859 1860 1861 | widely 1866 1869 1872 |
different conditions of life,
|