stand up for REAL science

"There are only two ways we know of to make extremely complicated things. One is by engineering, and the other is evolution. And of the two, evolution will make the more complex."

Danny Hillis

The Bacterial Flagellum
(drawing by Ethan Hein)

Intelligent Design promoter Michael Behe is most well known for coining the phrase "irreducibly complexity" to describe certain complex biological systems. According to Behe, "irreducibly complex" systems are so complicated that they could not have evolved through known evolutionary mechanisms. In a brazen act of self-promotion, Behe audaciously wrote in 1996 that the discovery of irreducible complexity should be ranked as "one of the greatest achievements in the history of science."

Here is how Behe described the concept of irreducible complexity in 2001:

"The main difficulty for Darwinian mechanisms is that many systems in the cell are what I termed 'irreducible complex.' I defined an irreducibly complex system as: a single system that is necessary composed of several well-matched, interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system to effectively cease functioning."

Behe, M.J. 2001. Reply to My Critics: A Response to Reviews of Darwin's Black Box: The Biochemical Challenge to Evolution, Biology and Philosophy 16:685-709.

Interestingly, the concept of "irreducible complexity" was not new in 1996.

Not by a long shot.

In fact, American geneticist Hermann J. Muller predicted and explained the existence of "irreducibly complex" biological systems over 90 years ago, and he did it using the REAL science of evolution. Of course Muller did not use the phrase "irreducible complexity," but the concept he described was almost exactly the same. In a discussion about why dominant mutant genetic factors in fruit flies had a tendency to be lethal, Muller proposed that

"...a complicated machine was gradually built up whose effective working was dependent upon the interlocking action of very numerous different elementary parts or factors, and many of the characters and factors which, when new, were originally merely an asset finally became necessary because other necessary characters and factors had subsequently become changed so as to be dependent on the former. It must result, in consequence, that a dropping out of, or even a slight change in any one of these parts is very likely to disturb fatally the whole machinery..."

Muller, H. J. 1918. Genetic variability, twin hybrids and constant hybrids, in a case of balanced lethal factors. Genetics 3:422-499. (emphasis in original)

As Muller explained in 1918, all that is necessary for "irreducible complexity" to evolve is for parts that were originally advantageous to the function of a larger system to become indispensable to the function of the system through further evolutionary changes. Continue this gradual process for many iterations, and you can end up with a very complicated system. Today, the bacterial flagellum (pictured above) is a great example of the kind of interlocking system that Muller described.

Thus, the notion that irreducible complexity is a barrier to gradual evolutionary processes is clearly false. Such a notion is actually contradictory to predictions made by evolutionary theorists for nearly a century.