| Again, it may be asked, how is it that varieties, which I have called incipient species, become ultimately converted into good and distinct species, which in most cases obviously differ from each other far more than do the varieties of the same species? How do those groups of species, which constitute what are called distinct genera, and which differ from each other more than do the species of the same genus, arise? All these results, as we shall more fully see in the next chapter, follow
from the struggle for life. Owing to this
→for life, any
however
and from whatever cause proceeding, if
be in any degree profitable to
of
species, in
infinitely complex relations to other organic beings and to
→external nature,
will tend to the preservation of
and will generally be inherited by
offspring. The offspring, also, will thus have a better chance of surviving, for, of the many individuals of any species which are periodically born, but a small number can survive. I have called this principle, by which each slight variation, if useful, is preserved, by the term
Natural Selection, in order to mark its relation to
power of selection. ↑
We have seen that man by selection can certainly produce great results, and can adapt organic beings to his own uses, through the accumulation of slight but
variations, given to him by the hand of Nature. But Natural Selection, as we shall hereafter see, is a power incessantly ready for action, and is as immeasurably superior to
feeble efforts, as the works of Nature are to those of Art.
|
