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Posted on 02/12/2006 10:32:27 AM PST by PatrickHenry

MORE THAN A CENTURY and a half since Charles Darwin wrote "On the Origin of Species," evolution remains a controversial concept among much of the population. The situation is quite different in the scientific community, where evolution is almost universally accepted. Still, attacks on the teaching of evolution continue.

The more recent criticism of evolution comes from proponents of intelligent design, a new label for creation "science." They claim ID is a valid scientific alternative to explaining life on Earth and demand it be taught in science classes in our schools along with evolution.

Although intelligent design is cloaked in the language of science and may appear at first glance to be a viable theory, it clearly is not. In fact, intelligent design is neither a theory nor even a testable hypothesis. It is a nonscientific philosophical conjecture that does not belong in any science curriculum in any school.

A theory in the scientific sense is quite different from how the word is often used in conversation.

Theories are structures of ideas that explain and interpret facts. They are based on extensive data and their predictions are tested and verified time and again.

Biological evolution -- genetic change over time -- is both a theory and a fact, according to paleontologist Stephen Gould. Virtually all biologists consider the existence of evolution to be a fact. It can be demonstrated in the lab and in nature today, and the historical evidence for its occurrence in the past is overwhelming.

However, biologists readily admit that they are less certain of the exact mechanism of evolution; there are several theories of the mechanics of evolution, which are supported by data and are constantly being refined by researchers whose work is subject to peer review.

But there are many established facts concerning evolution, according to R.C. Lewontin, Alexander Agassiz Professor Emeritus of Zoology at Harvard University. He, as do virtually all biological scientists, agree that it is a fact that the Earth with liquid water has been around for more than 3.6 billion years and that cellular life has been around for at least half of that period.

We know for a fact that organized multicellular life is at least 800 million years old and that major life forms now on Earth did not exist in the past.

It is considered a fact by biologists that all living forms today come from previous living forms.

A fact is not the same as absolute certitude, which exists only in defined systems such as mathematics. Scientists consider a "fact" to be something that has been confirmed to such a degree of reliability and logic that it would be absurd to think otherwise.

Denying the facts of evolution is akin to denying that gravity exists. What is debatable, with both evolution and gravity, are the theories of the mechanics of how each operates.

Supporters of intelligent design vehemently disagree, but they do not offer alternative theories or verifiable data. Instead, intelligent design proponents attack evolution with misinformation, half-truths and outright falsehoods.

Intelligent design does not develop hypotheses nor does it test anything. As such, intelligent design is simply a conjecture that does not hold up to scrutiny.

False arguments

Unfortunately, intelligent design has considerable credibility outside the scientific community by making specious claims about evolution. Below are some of the leading charges made by intelligent design and creationist proponents in the past several years.

• Evolution has never been observed: But it has. Biologists define evolution as a change in the gene pool of a population of living organisms over time.

For example, insects develop resistance to pesticides. Bacteria mutate and become resistant to antibiotics. The origin of new species by evolution (speciation) has been observed both in the laboratory and in the wild.

Some intelligent design supporters admit this is true, but falsely say that such changes are not enough to account for the diversity of all living things. Logic and observation show that these small incremental changes are enough to account for evolution.

Even without direct observation, there is a mountain of evidence that confirms the existence of evolution.

Biologists make predictions based on evolution about the fossil record, anatomy, genetic sequences and geographical distribution of species. Such predictions have been verified many times, and the number of observations supporting evolution is overwhelming and growing, especially in the field of genetics.

Biologists have not observed one species of animal or plant changing quickly into a far different one. If they did, it would be evidence against evolution.

• Evolution violates the second law of thermodynamics: It clearly does not. This law of physics states essentially that disorder increases in a closed system. Some intelligent design and creationist proponents say this means that the order required in the evolution of simple life forms to more complex ones cannot take place, at least not on a long-term basis.

What critics of evolution don't say is that the Earth's environment is not a closed system. It absorbs enormous heat energy from the sun, which is all that is required to supply fuel for the evolution of plants and animals.

Order arises from disorder in the physical world as well, in the formation of crystals and weather systems, for example. It is even more prevalent in dynamic living things.

• There are no transitional fossils: This argument is a flat-out falsehood. Transitional fossils are ones that lie between two lineages with characteristics of both a former and latter lineage. Even though transitional fossils are relatively rare, thousands of them have been found.

There are fossils showing transitions from reptile to mammal, from land animal to whale, the progression of animals leading to the modern horse, and from early apes to humans.

• Theory says that evolution proceeds by random chance: This is an example of a half-truth perpetuated by intelligent design and creation supporters.

Chance is an important element of evolution, but it is not the only thing involved.

This argument ignores other forces such as natural selection, which weeds out dysfunctional species, and is the opposite of chance.

Chance takes place in genetic mutations, which provide the raw material of evolutionary change, which is then modified and refined by natural selection. But even at the genetic level, mutations occur within the framework of the laws of physics and chemistry.

Opponents of evolution argue that chance, even enhanced by natural selection and the laws of physics, is not enough to account for the complexity of DNA, the basic building blocks of almost all life forms. (RNA is the foundation of some microbes). However, there literally were oceans of organic molecules that had hundreds of millions of years to interact to form the first self-replicating molecules that make life possible.

Irreducible complexity

The attack on evolution that intelligent design proponents use most often today is one based on "irreducible complexity." This has become the foundation of their attempts to cast doubt on evolution.

They argue that certain components of living organisms are so complex that they could not have evolved through natural processes without the direct intervention of an intelligent designer.

Michael Behe, a leading proponent of intelligent design, defined irreducibly complex as "a system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning."

In other words, irreducible complexity refers to an organism that does something (a function) in such a way that a portion of the organism that performs the function (a system) has no more parts than are absolutely necessary.

The argument made is that the entire system with all its parts, such as an enzyme used in digestion or a flagellum used to propel a bacterium (an example Behe favors in his defense of irreducible complexity), would have to come into being at one time -- a virtual impossibility.

If one of the parts were missing, Behe argues, the system would not be able to function, and thus a simpler, earlier evolving system could not exist.

It is not as easy as it may appear at first glance to define irreducible complexity because there is not a good definition of what a part is. Is it a particular type of tissue, a cell, or segment of DNA? Behe is not clear. But even if he were able to define a true IC system, his argument would fail.

There are several ways an irreducible complexity system could evolve. An early version could have more parts than necessary for a particular function. The individual parts could evolve. Most likely, an earlier version of the system could have had a different function.

This is observed in nature. For example, take the tail-like flagellum of a bacteria, which Behe says supports irreducible complexity. It is used for functions other than motion. A flagellum can be used to attach a bacteria to a cell or to detect a food source.

Thus, a precursor to a more complex flagellum could have had a useful, but different, function with fewer parts. Its function would have changed as the system evolved.

Simply put, the irreducibly complex system argument doesn't work. Most, if not all, of the irreducible complexity systems mentioned by intelligent design adherents are not truly IC. Even if they were, they clearly could have evolved. That is the consensus of almost all biological scientists.

Intelligent design is not science

The theory of evolution and common descent were once controversial in scientific circles. This is no longer the case.

Debates continue about how various aspects of evolution work. However, evolution and common descent are considered fact by the scientific community.

Scientific creationism, or intelligent design, is not science. Believers of intelligent design do not base their objections on scientific reasoning or data.

Instead, it appears that their ideas are based on religious dogma. They create straw men like irreducible complexity or lack of transitional fossils, and shoot them down. They fabricate data, quote scientists out of context and appeal to emotions.

Intelligent design disciples do not conduct scientific experiments, nor do they seek publication in peer-reviewed scientific journals.

Still, they have had an impact far beyond the merits of their arguments.

One of their most persuasive arguments is an appeal to fair play, pleading to present both sides of the argument. The answer is no. They do not present a valid scientific argument.

Within the scientific community, there is virtually no acceptance of intelligent design. It has no more place in a biology class than astrology in an astronomy class or alchemy in a chemistry class.

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