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Creation 30(3):53, June 2008

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Twiddling the knobs


Complex machines often have lots of knobs provided for adjustment: think of a jumbo jet, a television set or a DVD player. With a radio set you can twiddle the knobs to tune a different station or increase the volume or adjust the tone. But you can twiddle the controls on your radio as much as you like, it won’t change into a TV set.


The natural changes we see in living things are like twiddling the knobs on a complex machine: they can fine-tune the settings, but cannot create something completely new. For example, an enzyme in a bacterium might be optimized to work at a given temperature. If the bacterium finds itself in a slightly hotter environment, mutations can optimize the enzyme to work at the different temperature and natural selection would favour the new version. This is mere fine-tuning of existing abilities; twiddling the knobs.

With antibiotic resistance, a mutation can result in the loss of control over the production of an enzyme that destroys the antibiotic. That’s like getting a defect in your radio’s volume control so that it is stuck ‘full on’; this entails a loss of functionality in your radio. This is not the sort of change that will change the bacterium into something more complex.

Mutations cannot create brand new knobs—new enzymes unlike ones that already existed, for example, or harder still, whole new metabolic pathways or cycles that need multiple proteins/enzymes. Scientists recognize hundreds of families of proteins, which differ significantly from one another—they could be seen as different knobs on a machine, although they are really much more complex than a volume control on a radio. Many proteins are components in even more complex machines, such as rotary motors like the bacterial flagellum and ATP synthase, or linear motors like kinesins (which ‘walk’ along special roads within cells carrying bags of components to their intended destinations).

If you want to make a TV set, it is no use just twiddling the knobs on a radio receiver. You have to design the TV from the ground up so that it will operate as a TV set. There are complex components in a TV that a radio does not have: like a cathode ray tube (for the ‘old-fashioned’ type of TV) or an LCD or plasma display. Nothing in a radio can be tweaked by a sequence of little changes to make these components.

Likewise, if you want ‘nature’ to make a bird from a reptile, you have to somehow generate some components that are completely missing from reptiles. You can’t just twiddle the knobs on a reptile to change it into a bird. For starters, the breathing system is totally different: a reptile has a bellows-like system, whereas birds have a flow-through system. And birds have the specifications for making feathers, which reptiles don’t. No, you have to design a bird to get a bird.

Now the evolutionists argue that because a bird has some components that are similar to reptiles (like scales on their feet) that this must be because they shared a common ancestor. That’s like arguing that because the TV has a volume control with similarities to a radio that the radio and TV had a common ancestor, or the TV evolved from a radio. But no, they have some similar components (knobs, even) because the intelligent designer of the TV saw that there were elements of the radio design that could be also used in the TV design; there was no need to ‘re-invent the wheel’.

Next time you hear the latest example of ‘evolution in action’ ask yourself whether they are just talking about twiddling the knobs, or is ‘Nature’ truly creating something brand new.

Posted on homepage: 19 October 2009