God: The Failed Hypothesis (6 page)

Today we understand the process of natural selection in terms of the genetic information carried in the
DNA
of cells and how it is modified by random mutations. It is not my purpose here to give yet another exposition of evolution. Darwin’s theory, updated by the many developments since his time, resides at the foundation of modern biology. Evolution by natural selection is accepted as an observed fact by the great majority of biologists and scientists in related fields, and is utilized in every aspect of modern life science including medicine. In terms of the same strict standards of empirical evidence that apply in all the natural sciences, Darwinian evolution is a well-established theory that has passed many critical tests.

A common argument made by opponents of evolution is that it is not a “true” scientific theory, like electromagnetism or thermodynamics. They wrongly claim that evolution does not make predictions that can be tested and is thus not falsifiable. In fact, evolution is eminently predictive and falsifiable.

Darwin specifically predicted that recognizable human ancestors would be found in Africa. Many now have been. Evolutionary theory predicted that the use of antiviral or antibacterial agents would result in the emergence of resistant strains. This principle is, of course, a mainstay of contemporary medicine. Paleontologists correctly predicted that species showing the evolution from fish to amphibian would be found in Devonian strata.

This example, among many, refutes the frequently heard creationist claim that “transitional forms” (presumably meaning transitional species) do not exist. Paleontologists had expected to find transitions from land-based mammals to whales for years. In the past decade, science journals, as well as the media, have been full of these finds. A simple Internet search will yield hundreds of examples of transitional species.

The failure of many of these predictions would have falsified evolution. They did not fail. It is a trivial exercise to think of other ways to falsify evolution. For example, evolution would be falsified if we were to find bona fide remains of organisms out of place in the fossil record. Suppose mammals (horses, humans, or hippos) were found in the Paleozoic strata associated with trilobites, crinoids, and extinct corals. This would show that there was no evolutionary process. But we do not find any such inconsistencies.

My favorite example is over a hundred years old. Shortly after its publication in the nineteenth century, the theory of evolution was challenged by the famous physicist William Thomson, Lord Kelvin, whose thermodynamic calculations gave an age for Earth that was much too short for natural selection to operate. Darwin regarded this as the most serious challenge to his theory.

However, at the time, nuclear energy was unknown. When this new form of energy was discovered early in the twentieth century, Kelvin and other physicists quickly realized that the energy released by nuclear reactions at the center of the sun would be very efficient, allowing the sun and other stars to last billions of years as a stable energy source. In fact, evolution can be said to have predicted the existence of such an energy source!

When he learned of nuclear energy, Kelvin graciously withdrew his objection to evolution.

As we will find several times in this book, some scientific arguments for the existence of God once had considerable force, and it was not until recently—within the last century—that accumulated knowledge not only eliminated these lines of reasoning but also turned many of them on their heads to support the case against God. These examples amply refute the claim that science has nothing to say about God. One can imagine endless scenarios by which observations of the universe and life on Earth might confirm God’s existence; we will mention just a few in this book.

The discovery of human ancestors, the
DNA
and anatomical connections between humans and other animals (and even plants), and the use of animals in medical research falsify the hypothesis of a God who created humans as a distinct life-form.

The fossil record, the existence of transitional species, and the actual observation of evolution in the laboratory falsify the hypothesis of a God who created separate “kinds” or species of life-forms at one time in history and left them unchanged since.

It might have been otherwise.

Many believers see no conflict between evolution and their faith. After all, God can do anything he wants. If he wanted to create life by means of evolution, then that’s what he did. However, other believers have good reason to regard evolution as threatening to their own faith in the purposeful, divine creation of human life
⁶
.

Evolution implies humanity was an accident and not the special creature of traditional doctrine. Many find this unacceptable and conclude, despite the evidence, that evolution must be wrong.

However, if we are to rely on science as the arbiter of knowledge rather than ancient superstitions, the opposite conclusion is warranted. Evolution removes the need to introduce God at any step in the process of the development of life from the simplest earlier forms. It does not explain the origin of life, so this gap still remains. This is insufficient to maintain consistency for some believers, especially since evolution is in deep disagreement with the biblical narrative of simultaneously created immutable forms. Furthermore, we have no reason to conclude that life itself could not have had a purely material origin.

The Creationists

While a continuum of creationist views from extreme to moderate continues to be heard, we can still identify a few dominant strains. Let us look at the recent history. According to Ronald Numbers, author of the definitive early history
The Creationists,
the term
creationism
did not originally apply to all forms of antievolution
⁷
. Opponents of evolution were not always committed to the same, unified view of creation. However, by the 1920s, the biblical creation story became the standard alternative to evolution in the United States and the creationist movement its champion.

In that decade, Christian fundamentalists in the United States took over the front line of the battle. Under their influence, three states—Tennessee, Mississippi, and Arkansas—made the teaching of evolution a crime. Oklahoma prohibited textbooks promoting evolution, and Florida condemned the teaching of Darwinism as “subversive.”

In 1925 biology teacher John Scopes was brought to court in Dayton, Tennessee, for teaching evolution. This led to the sensational “Monkey Trial,” with Clarence Darrow for the defense pitted against three-time losing Democratic presidential candidate William Jennings Bryan for the prosecution. Although Scopes was convicted (later overturned on appeal), the trial is still widely regarded as a public relations triumph for the Darwinians, as somewhat inaccurately depicted in the play and film
Inherit the Wind.

A new strain of creationism appeared in 1961 with the publication of
The Genesis Flood
by theologian John C. Whitcomb Jr.

and hydraulic engineer Henry M. Morris
⁸
, who were strongly influenced by earlier efforts by Seventh-day Adventist leader George McCready Price. The authors argued that science was compatible with Genesis, and although their scientific claims were not credible, conservative Christians sat up and took notice—

recognizing a new strategy for combating hated Darwinism.

Around 1970 Morris founded the Institute for Creation Science, which then led a movement to have the new “creation science” presented in public-school science classrooms. Biochemist Duane Gish traveled the country on behalf of the institute, giving talks and ambushing naive biologists in debates before huge, receptive audiences of churchgoers. Arkansas and Louisiana passed laws mandating the teaching of creation science alongside evolution.

In 1982 a federal judge in Arkansas tossed out the law in that state, declaring creation science to be religion and not science
⁹
. In 1987 the Supreme Court ruled the Louisiana law unconstitutional.

About this time, creation science speciated into two main branches, one holding to the more literal biblical picture of a young Earth and another that attempts to use sophisticated arguments that appear, at least to the untutored eye, more consistent with established science. The second group has developed a new stealth creationism called
intelligent design,
which has the common shorthand, “ID.”

The Wedge of Intelligent Design

Learning from the mistakes of the creation scientists, proponents of ID downplay their religious motives in a so far not very successful attempt to steer clear of the constitutional issue. They also have avoided the more egregious scientific errors of the young-Earth creationists, and present this new form of creationism as “pure science.” They claimed that design in nature can be scientifically demonstrated and that the complexity of nature can be

proved
not to have arisen by natural processes alone
¹⁰
.

In
Creationism’s Trojan Horse: The Wedge of Intelligent Design,
philosopher Barbara Forrest and biologist Paul Gross detail the story of how the new creationism is fed and watered by a wellfunded conservative Christian organization called the Discovery Institute
¹¹
. The goals of this organization, documented by Forrest and Gross, are to “defeat scientific materialism and its destructive moral, cultural, and political legacies” and to “renew” science and culture along evangelical Christian lines.

Behe’s Irreducible Complexity

None of the claims of intelligent design proponents, especially the work of its primary theorists, biochemist Michael Behe and theologian William Dembski, have stood up under scientific scrutiny. Numerous books and articles have refuted their positions in great detail
¹²
. Not only have their arguments been shown to be flawed, but also in several instances the factual claims on which they rest have been proven false. None of their work has been published in respected scientific journals
¹³
.

Behe’s fame rests on his 1996 popular-level book,
Darwin’s Black Box: The Biochemical Challenge to Evolution
¹⁴
.
There he introduced the notion of
irreducible complexity,
which occurs when a system is reduced to several parts and can no longer function when any of the parts is removed. Behe argued that the individual parts could not have evolved by natural selection since they no longer have any function on which selection can operate.

Thoroughly refuting Behe’s argument, evolutionary biologists have listed many examples in nature where an organic system changes functions as the system evolves
¹⁵
. They have provided plausible natural mechanisms for every example Behe presents, many of which were well known (except to Behe) before Behe ever sat down to write.

The manner in which the parts of living systems change function over the course of evolution is one of those well-established facts of evolution that Behe and other proponents of intelligent design choose to ignore. Biological parts often evolve by natural selection by virtue of one function, and then gradually adapt to other functions as the larger system evolves.

Many examples of organs and biological structures that are understood to have arisen from the modification of preexisting structure rather than the elegance of careful engineering can be found in the biological literature. Paleontologist Stephen Jay Gould made this point in his wonderful example of the panda’s thumb
¹⁶
. The panda appears to have six fingers, but its opposing “thumb” is not a finger at all but a bone in its wrist that has been enlarged to form a stubby protuberance handy for holding a stalk of bamboo shoots, the panda’s only food.

Behe is a biochemist, not an evolutionary biologist, and was unaware when he wrote his book that the mechanisms for the evolution of “irreducibly complex” systems were already discussed six decades earlier by the Nobel Prize winner Hermann Joseph Muller and have been common knowledge in the field since then
¹⁷
. Behe cannot even be forgiven for simply falling into the God of the gaps trap. He did not even find a gap.

The Eye

Let us look at the frequent example used by creationists since Paley: the human eye. In
The Blind Watchmaker,
which was primarily a contemporary evolution scientist’s response to William Paley, zool-ogist Richard Dawkins pointed out that the eye in all vertebrates is wired backward, with the wires from each light-gathering unit sticking out on the side nearest the light and traveling over the surface of the retina where it passes through a hole, the “blind spot,” to join to the optic nerve
¹⁸
. Other animals, such as the octopodes and squids, have their eyes wired more rationally.

This is often presented as an example of apparent “poor design.” However, biologist (and devout Catholic) Kenneth Miller does not think this is a fair designation, since the arrangement still works pretty well. He has shown how the wiring of the vertebrate is nicely described by evolution
¹⁹
. The retina of the eye evolved as a modification of the outer layer of the brain that gradually developed light sensitivity. The eye is neither poorly nor well designed. It is simply not designed.

Eyes provide such obvious survival value that they developed at least forty times
independently
in the course of evolution
²⁰
. Neuroscience has identified eight different optical solutions for collecting and focusing light, although all share similarities at the molecular and genetic levels
²¹
. The physics and chemistry are the same; few ways exist for detecting photons. But, because of the important role of chance and local environment in the evolution of complex systems, different solutions to the problem were uncovered by random sampling of the varied paths allowed by evolution. In short, the structures of eyes look as they might be expected to look if they developed from purely material and mindless processes—