Myth: Life obviously had an intelligent designer.
Fact: The appearance of design is actually biological efficiency enhanced by natural
selection.
Summary
Life has indeed been designed, but by whom or what is the
central controversy. Creationists believe it was an intelligent
designer, namely, God; evolutionists believe it was a driving
force of nature, namely, natural selection. Natural selection
works when life forms with advantageous survival traits live long
enough to breed, therefore passing on those traits to the next
generation. Life forms with weaker traits die before breeding,
and therefore disappear from the gene pool. Genetic diversity
results in slight variations of these hereditary traits from generation
to generation, which allows a species to adapt to the changing
demands of a changing environment. This results in a suitability
between life form and environment that many people mistake for
intelligent design.
Argument
In the 18th century, the scientific world was neck-deep in
clues of evolution, but a simple counter-argument had stopped
scientists from accepting a theory on evolution. This was Bishop
Paley's argument that life had obviously been designed. For example,
if a person who had never seen a watch before was walking through
the woods and discovered one, he would know by its interdependent
features and functions that it had been designed and manufactured
by another human. The same point can be made of life. The human
eye, for instance, exhibits all the evidence of design: the transparency
of the cornea, the adjustability of the pupils for light, the
curvature of the lens for focus, all cooperate together to serve
sight. This interdependency to serve a greater function could
only be the product of design. Design must have a designer. And
that designer, Paley argued, is God.
The 18th century Scottish philosopher David Hume could
not explain the appearance of design in nature, but he was the
first to point out the flaw in Paley's logic. The problem is one
of choosing the correct analogy. He pointed out that the universe
more resembles a living organism than a mechanical watch -- which
indicates that the universe must have started as a fetus in a
cosmic womb! Other scholars also lampooned Paley's argument; Voltaire
argued that noses must have been designed to hold up glasses,
and that bunny rabbits must have been given white tails so they
could be easier to shoot. The idea of design was so thoroughly
and effectively ridiculed that theologians of the time actually
stopped using it as an argument, although, curiously enough, it
would resurface in the 20th century.
Darwin essentially agreed that life had been designed, although
not necessarily by the designer that Paley evoked. Darwin's advance
on the argument was that the designer did not have to be an intelligent
being, but could also be a driving force of nature. Consider the
example of horse-breeding. A rancher can select any trait among
his horses that he would like to emphasize -- for example, small
size. By breeding his smallest horses together, he will eventually
obtain a line of miniature horses. Evolutionists cite this as
proof that species can change as a result of selective breeding.
Creationists respond -- quite rightly -- that the process needs
a designer, in this case the rancher. But evolutionists point
out that the same process happens in nature. Imagine a land separated
by a mountain range a thousand miles long. Horses are originally
found only on one side of the mountain range, which is sufficiently
tall to prevent passage to the other side. But suppose the horse
population finds a craggy pass in the mountains, only so narrow
that only the smallest of horses can pass through. Of course,
young horses don't like to be separated from their parents, so
large horses and their offspring would remain on one side the
pass, while small horses and their offspring would migrate to
the other side. There, they would establish their own population
of small horses, which would then breed and produce offspring
who also turn out to be small. Thus, a demand of the environment
changes the species.
Darwin's fame resides in the fact that he identified the forces
of nature which design life. Instead of an intelligent being selecting
which members should breed with each other for certain characteristics,
nature would select for these characteristics, hence the
term "natural selection." Darwin identified three factors
responsible for natural selection: