Encyclopedia of Evolution.pdf - Online Reading Center

426 appendix
Why, on the theory of Creation, should there be so much
variety and so little real novelty?
Organs of seemingly little importance. Sometimes complex
organs exist which seem to be of little importance to
the organisms—how could natural selection have produced
them? [Why would a Creator have put them there, for that
matter?] But this is more a problem of our knowledge than of
evolutionary process. For why should any such organ, even
if specially created, continue to exist, if it were really useless?
Surely it must have some function, or else have had some
value to the ancestors of the species that now possesses it (see
vestigial characteristics).
Some authors have claimed that complex organs exist
merely for the sake of beauty in the eyes of human beholders.
Natural selection tells us that this is never the case. Why
did beautiful seashells exist in the Eocene epoch, then become
extinct—simply so that fossil shell hunters could find them
and enjoy them? Why were ancient diatoms so beautiful—just
so that students of fossils could admire them under the microscope?
Why are flowers beautiful? Wind-pollinated flowers of
oak and nut trees are not beautiful, because the wind is not
attracted by their beauty. Other flowers are beautiful, not for
our sake but because they attract insect and bird pollinators.
Many male birds are beautiful, not to impress bird-watchers
but to impress female birds. Do not press this argument too
far—if God put beauty into the world just for us, then why
did he put into the world the ugliness which parasites inflict
upon their hosts?
Nature will never produce absolute perfection, but natural
selection produces adaptations that are only as good as they
need to be to outdo the competition. There are, in fact, examples
of imperfection in the natural world; this is an understandable
result of natural selection, not a criticism of God.
chapter 7. Miscellaneous Objections
Many of the criticisms that my work has occasioned are not
worth answering, because they have been made by people
who have not bothered to study my theory, or natural history.
For example, one critic said that evolution must produce
new species, each of which has a longer life span than its
predecessors, which is ridiculous, because a shorter life span
might very well have greater adaptive benefits to survival, as
some short-lived weeds are more successful than trees in disturbed
habitats. But to those that are worthy of an answer, I
continue to respond in this chapter.
The natural world simply must contain some kind of
evolution, since if each species were originally created to be
perfectly adapted to its original conditions, they would have
to change in order to adjust to new conditions.
I here respond to three important objections:
1. When we compare modern livestock with those depicted
in Egyptian hieroglyphics, we see that no evolutionary
changes have occurred during that span of time. This is
hardly surprising, as a couple of thousand years is nothing
compared to an evolutionary time span.
2. Varieties and species do not differ from one another in single
characters but in many ways. This is not a problem for
natural selection, which acts upon organisms, with all of
their characteristics.
3. How could natural selection have produced characteristics
that are of no use to the organisms that possess them?
Some naturalists have claimed that such characteristics
are common. However, we must be very careful when we
say that a characteristic is of no use, simply because we
do not know what it is used for. Consider the dimorphic
and trimorphic flowers, in which different plants within
a species have flowers with different lengths of stamens
and pistils. At first this arrangement appeared to have no
function, but we now know that it promotes cross-pollination.
In some cases, differences among species have
resulted from the accidents of ancestry. For example,
feathers and hair might be equally effective in holding
in warmth, but birds always have feathers and mammals
have hair—not because it is necessarily better for birds to
have feathers than hair, and mammals to have hair rather
than feathers, but simply because they have inherited
these characteristics.
One must admit the art and force of the objections published
by St. George Jackson Mivart in his 1871 book, The
Genesis of Species. But he is wrong. Some of his objections
arise from his mistakes. For example, he says that mammary
glands could not have evolved, since a rudimentary gland
producing only a drop of fluid would not have helped a baby
animal in a transitional species. But, in fact, while such an
arrangement might not work in an early mammal with external
mammae, such an arrangement would have been beneficial
in marsupials, in which the mammae are protected inside
a pouch—a factor that Mivart seems to have overlooked.
However, other objections raised by Mivart deserve answers.
1. One of his objections involves the giraffe. He asks if having
a long neck is such an advantage to the giraffe, why
haven’t all the other African grazing mammals evolved
long necks? But once giraffes began to evolve long necks,
allowing them to reach higher into the trees for leaves to
eat, it would not be an advantage for any other animals
to do so, unless they could outreach the newly evolving
giraffes. [It now appears that the neck of the giraffe
evolved by sexual selection; see adaptation).] Other
authors have raised similar objections, such as, why
haven’t ostriches evolved the power of flight? I think
the answer is obvious—ostriches are doing so well with
running, and the energy and modifications of structure
required for flight are so great, that it simply would not
be worth it and would not be selected by the evolutionary
process. Flight is not always better for birds. This is
why there are no islands on which seals have evolved into
terrestrial forms or bats into ground-dwelling forms—the
advantages of staying as they are have outweighed the
advantages of changing. Why haven’t apes [other than
humans] evolved high intelligence? Intelligence is over-