Sunday, June 25, 2006

A Bug By Design?

The debate between creationists and evolutionists has been a lively and engaging one over the years. The creationists have applied the concept of a master creator and the corollary of "form follows function" to everything from bacteria to butterflies. The lines have never been drawn more clearly, nor the arguments more vociferous, as those over the curious creature called the Bombardier beetle. The bug appears to be an irreducible complexity.

Michael Behe, the originator of the concept (in that he first articulated it) defines irreducible complexity (IC) as "a single 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." An irreducibly complex system breaks down the theory of evolution. Such a system can be deemed as having been "engineered".

What is IC about the Beetle? Why, it's defense system for which it is named. It earned its common name from its ability to defend itself against predators by firing a mixture of boiling-hot toxic chemicals from special glands in its posterior.

The mechanism of the spray works thus: Secretory cells produce hydroquinones and hydrogen peroxide, which collect in a reservoir. The reservoir opens through a muscle-controlled valve onto a thick-walled reaction chamber. This chamber is lined with cells that secrete catalases and peroxidases. When the contents of the reservior are forced into the reaction chamber, the catalases and peroxidases rapidly break down the hydrogen peroxide and catalyze the oxidation of the hydroquinones into p-quinones. These reactions release free oxygen and generate enough heat to bring the mixture to the boiling point and vaporize about a fifth of it. Under pressure of the released gasses, the valve is forced closed, and the chemicals are expelled explosively through openings at the tip of the abdomen.

The professional biologist refutes the charge by pointing out that all the subsystems in the defense system are found in other bugs. Personally, I think, there is a missing component to the theory of evolution. Personally, I am not sure if the Bombardier Beetle is an ASIC (Application Specific Irreducibly Complex) design or not.

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