The Evolution of Form
When discussing evolution it is helpful to distinguish between those aspects of animals that are naturally variable and those which are far more inflexible. Take, for instance, the shape, form or color of an animal. Beaks can be long or short, straight or curved. Fur can be dark or light, yellow or brown. And indeed, evidence that life varies in terms of form and color abound. Note, for instance, the following experiment:
This experiment demonstrates that the silver fox is extremely flexible in terms of behaviors, shapes and colors. Indeed, not only can the silver fox turn into a dog-like, loveable pet, but he can also be transformed into a vicious beast:
But there is another remarkable fact that we can glean from this experiment. The variability displayed by the silver fox are built into the genetic and molecular makeup of the fox. And that means that there is a limit to the amount of variation we can expect to see displayed by the silver fox or any other living creature.
Put otherwise, the silver fox can only vary as much as he or she is built to vary — no more and no less. To extrapolate beyond that limit is to allow ones imagination to travel beyond what the evidence shows.
Of course, some people have rather vivid imaginations:
…think about the difference between any one breed of dog and any other…and then extrapolate backwards twenty thousand times as far into the past. It becomes rather easy to accept that evolution could accomplish the amount of change that it took to transform a fish into a human. [Richard Dawkins, The Greatest Show on Earth, p. 81]
This statement, to put it mildly, is ridiculous. The silver fox is still a fox and each and every dog is still a dog. What's more, all the finches and turtles with their different shaped beaks and shells and all the mice and moths with their different colored furs and wings are still finches, turtles, mice and moth. No amount of variation or change in their shapes, colors or behaviors can change this fact.
But to change a fish into a man you need to do more (much more) than simply change external shape and color. A fish in the form of a man cannot breathe out of water, think complex thoughts, play musical instruments or even hold a pencil. Without the brain, lungs, heart, muscles, skeleton, DNA, nervous system and more of a man, a fish in human form will be about as useless a creature as you can imagine. Unable to live on land, unable to swim at sea.
In short, the form of life can teach us nothing about the machinery of life. Shape is malleable and can easily vary. The same is not true for the machinery that makes up life. Machines are made up of specifically designed parts of exact sizes and shapes which are fit precisely together in order to function in a very specific manner. Change one of these aspects and more often than not the machine simply won't work.
And it is this difference between form and machines which has plagued evolutionary theory from Darwin to Dawkins. Evolutionary theory breaks down when it tries to account for the machinery of life. Attempts to explain the evolution of features such as the eye or the bacteria flagellum 'succeed' only when they a) strip away all the features of the machinery in question which do not fit into an evolutionary framework or b) change the subject to cover up the fact that they do not have a scientific explanation.
Changing the facts or avoiding the question are not solid foundations for a scientific theory. But that is what they do — as we shall see in the posts to come.
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