Message #129022

[Bullseye]

The belief in the power of sexual selection rests chiefly on the
following considerations. Certain characters are confined to one
sex; and this alone renders it probable that in most cases they are
connected with the act of reproduction. In innumerable instances these
characters are fully developed only at maturity, and often during only
a part of the year, which is always the breeding-season. The males
(passing over a few exceptional cases) are the more active in
courtship; they are the better armed, and are rendered the more
attractive in various ways. It is to be especially observed that the
males display their attractions with elaborate care in the presence of
the females; and that they rarely or never display them excepting
during the season of love. It is incredible that all this should be
purposeless. Lastly we have distinct evidence with some quadrupeds and
birds, that the individuals of one sex are capable of feeling a strong
antipathy or preference for certain individuals of the other sex.
  Bearing in mind these facts, and the marked results of man's
unconscious selection, when applied to domesticated animals and
cultivated plants, it seems to me almost certain that if the
individuals of one sex were during a long series of generations to
prefer pairing with certain individuals of the other sex,
characterised in some peculiar manner, the offspring would slowly
but surely become modified in this same manner. I have not attempted
to conceal that, excepting when the males are more numerous than the
females, or when polygamy prevails, it is doubtful how the more
attractive males succeed in leaving a large number of offspring to
inherit their superiority in ornaments or other charms than the less
attractive males; but I have shewn that this would probably follow
from the females,- especially the more vigorous ones, which would be
the first to breed,- preferring not only the more attractive but at
the same time the more vigorous and victorious males.
  Although we have some positive evidence that birds appreciate bright
and beautiful objects, as with the bower-birds of Australia, and
although they certainly appreciate the power of song, yet I fully
admit that it is astonishing that the females of many birds and some
mammals should be endowed with sufficient taste to appreciate
ornaments, which we have reason to attribute to sexual selection;
and this is even more astonishing in the case of reptiles, fish, and
insects. But we really know little about the minds of the lower
animals. It cannot be supposed, for instance, that male birds of
paradise or peacocks should take such pains in erecting, spreading,
and vibrating their beautiful plumes before the females for no
purpose. We should remember the fact given on excellent authority in a
former chapter, that several peahens, when debarred from an admired
male, remained widows during a whole season rather than pair with
another bird.
  Nevertheless I know of no fact in natural history more wonderful
than that the female Argus pheasant should appreciate the exquisite
shading of the ball-and-socket ornaments and the elegant patterns on
the wing-feather of the male. He who thinks that the male was
created as he now exists must admit that the great plumes, which
prevent the wings from being used for flight, and which are
displayed during courtship and at no other time in a manner quite
peculiar to this one species, were given to him as an ornament. If so,
he must likewise admit that the female was created and endowed with
the capacity of appreciating such ornaments. I differ only in the
conviction that the male Argus pheasant acquired his beauty gradually,
through the preference of the females during many generations for
the more highly ornamented males; the aesthetic capacity of the
females having been advanced through exercise or habit, just as our
own taste is gradually improved. In the male through the fortunate
chance of a few feathers being left unchanged, we can distinctly trace
how simple spots with a little fulvous shading on one side may have
been developed by small steps into the wonderful ball-and-socket
ornaments; and it is probable that they were actually thus developed.
  Everyone who admits the principle of evolution, and yet feels
great difficulty in admitting that female mammals, birds, reptiles,
and fish, could have acquired the high taste implied by the beauty
of the males, and which generally coincides with our own standard,
should reflect that the nerve-cells of the brain in the highest as
well as in the lowest members of the vertebrate series, are derived
from those of the common progenitor of this great kingdom. For we
can thus see how it has come to pass that certain mental faculties, in
various and widely distinct groups of animals, have been developed
in nearly the same manner and to nearly the same degree.
  The reader who has taken the trouble to go through the several
chapters devoted to sexual selection, will be able to judge how far
the conclusions at which I have arrived are supported by sufficient
evidence. If he accepts these conclusions he may, I think, safely
extend them to mankind; but it would be superfluous here to repeat
what I have so lately said on the manner in which sexual selection
apparently has acted on man, both on the male and female side, causing
the two sexes to differ in body and mind, and the several races to
differ from each other in various characters, as well as from their
ancient and lowly-organised progenitors.