Flagellar Motor

We tend to think of bacteria as simple, disease-causing organisms which are nothing special to care about and could have little bearing on the origins debate. However, this is a flawed philosophy.  Bacteria are incredibly designed creatures, with incredible specified complexity. They cohabitate with just about every species on the planet, including humans. Without these tiny microbes, human life would be difficult to impossible. Thus it is wise to give bacteria a second look. This article will be about just one aspect of the incredibly designed microscopic bacterium, the flagella.

Many bacteria have flagella, though not all.  The flagellum is an outward projection from the body of a bacteria, powered by an internal motor that can be lashed through whatever liquid the bacteria inhabit to propel it in a given direction. There are different types of flagella but for the purposes of this article, we will consider the as one type for simplicity. Many flagellar bacteria have multiple, sometimes dozens of flagella.  The flagellum is composed of three main parts. The filament is the whip-like cord we observe on the outside. The flagellum attaches to the internal motor giving it energy by means of a device called a hook.

The filament is made of a special protein called flagellin. The protein is arranged in a long slender hollow tube to form the filament. It tapers towards the end to a point. By rapidly spinning the filament, the bacteria gain the ability to move. In bacteria with multiple flagella, the flagella are often controlled independently. This means they can be turned on and off separately, meaning the bacteria can use them to steer and adjust speed.

The hook is the point of attachment between the filament and the basal body, otherwise called the motor. A recent study has pointed out how crucial the hook is to the smooth operation of the whole flagellum. Researchers examined the hook and discovered it is precisely sized for stability. Any larger or smaller and the flagella would be unstable and the bacteria would have trouble swimming.

As if the other parts were not complex enough, the flagellar motor exhibits incredible specified complexity. It is composed of three to four parts, depending on the type of bacteria involved. If the bacteria are Gram-negative, then it has what is called an L-ring on the outside of the cell that connects the hook to the motor. Just inside that layer, anchored in the cell membrane is the P-ring, which is essentially the path through the cell membrane for the hook. The M-S ring is next. It serves as a stabilizer for the base of the hook as it connects into the motor at the bottom. The motor itself comes from the C ring which is anchored in the bacterial cytoplasm and consists of a ring with a disk inside. The hook attaches to the disk. When the disk rotates, the flagella is spun.

The motor complex is incredible, not just because of the specified complexity involved, but because it is irreducibly complex. The term “irreducible complexity” was coined by Dr. Michael Behe over a decade ago. The term is a reference to any feature which cannot be broken down beyond a certain point and still have a function. The classic example Dr. Behe used was that of a mousetrap. A mousetrap requires a certain number of parts to remain a functional mousetrap. While the basic design can be improved upon and made more complicated, it cannot be made less complex and still work.  The bacterial flagellum requires a minimum of forty separate proteins just to function. Drop that number to thirty-nine and the flagella will cease to function.

Consider this incredible piece of nanotechnology in light of origins. How could something with as much integrated, specified complexity as a bacterial flagellum come about by chance and random natural processes?  Evolutionists have proposed cooption as one explanation.  What this means is that the proteins originated elsewhere and were gradually assembled together into the flagella. This argument is specious for a number of reasons. The most obvious one is how did the cell know how to build such a complex structure? Where did the information come from? That is, of course, assuming you even had a cell, to begin with. However, there is another issue. Of the forty proteins required, about ten are found nowhere else in the bacterial cell. They are unique to the flagella. Thus they could not have simply been acquired elsewhere.

Creationists, on the other hand, can point to the flagella with confidence, knowing it was designed by the Almighty Hand of the Creator.  The specified, integrated complexity would not be dismissed as a result of chance and random natural processes if an engineering student turned it in as a class project. Yet when it is found in nature, it is somehow a result of chance.  Evolutionist deny the obvious design in the world in order to maintain their worldview.