Finally, then, I conclude that the greater variability of specific characters, or those which distinguish species from species, than of generic characters, or those which
→the species possess in common;—
that the frequent extreme variability of any part which is developed in a species in an extraordinary manner in comparison with the same part in its congeners; and the
degree of variability in a part, however extraordinarily it may be developed, if it be common to a whole group of
that the great variability of secondary sexual characters, and
great
difference in
→these same characters between
closely allied
that secondary sexual and ordinary specific differences are generally displayed in the same parts of the
are all principles closely connected together. All being mainly due to the species of the same group
→having descended from
a common progenitor, from whom they have inherited much in
to parts which have recently and largely varied being more likely still to go on varying than parts which have long been inherited and have not
to natural selection having more or less completely, according to the lapse of time, overmastered the tendency to reversion and to further
to sexual selection being less rigid than ordinary
and to variations in the same parts having been accumulated by natural and sexual selection, and
→thus
adapted for secondary sexual, and for ordinary
purposes.
|