Tornado in a Junkyard

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    Thatís the name and basic concept of one of the Creationistsí more popular scams. Am I being unjust in calling it a scam? No, because the Creationists should know better. They should learn what the theory of evolution actually says, instead of offering up false analogies to criticize the parody of evolution that they have established in their minds.

    In the analogy we are asked to imagine a tornado sweeping through a junkyard and leave behind it a perfectly new, fully functioning automobile. We all agree that such a thing is impossible: it will never happen. The idea that the turbulent vortex of a tornado could, by chance, bring together all of the right parts and so manipulate them that they fasten to each other in the right way simply doesnít match anybodyís picture of Reality.

    But then the Creationist claims that evolution is like that. Itís not. Unlike the parody criticized by the Creationists, the theory of evolution is not based on pure chance. The theory, properly understood, claims that evolution comes about through a combination of random mutation and natural selection operating on self-replicating entities.

    We want an analogy that will help people to better understand the theory of evolution; specifically, we want a mechanical analogy. We want something that shares certain features with the theory: the more features it shares (or the more fundamental the features that it shares), the better the analogy. The best analogy that I can imagine compares evolution to a Jacquard loom.

    Introduced in 1801, the Jacquard loom was a mechanism that used a chain of thick paper cards with holes punched in them to control a mechanical loom. With enough cards in the chain, the loom could weave fabrics displaying elaborate patterns. The Jacquard loom was the precursor of the modern stored-program computer. It inspired Charles Babbage in the design of his Analytical Engine and Herman Hollorith (inventor of the mechanical tabulator that used the punch-card system that he adapted and was later used by IBM).

    But the chain of cards can control any mechanism, so imagine a machine that uses the punched-card system to make copies of itself. As the chain proceeds, card-by-card, through the reader, the machine draws parts from bins and assembles them. In this way one machine becomes two, two machines become four, four machines become eight, and so on. As long as parts get put into the input bins, the assemblers will continue making copies of themselves.

    Now assume that some of the cards on one machineís chain get altered: some holes get covered up and/or more holes get punched into the cards. The machine using those cards will not produce a duplicate of itself. What it does produce wonít work well, if it works at all. But on very rare occasions the output will work a little better than the machine that created it, perhaps work a little more efficiently. As the machines produce the machines that will replace them when they wear out, the mutant machine will do so faster than the others do and eventually the mutantís offspring, themselves mutants, will predominate in the population. The machines will have evolved.

    We have an analogy with the evolution of a lifeform because in the analogy the parts coming into the machineís input bins correspond to the simple chemicals coming into a cell from its environment, the machineís structure and operation correspond to the chemical processes (such as the creation of proteins) that occur in a cell, and the chain of punched cards corresponds to and functions like the strands of DNA in a cell. This is a proper analogy because it has parts and processes that match up. This is how a good analogy works. Because we have a clearer picture of how a Jacquard loom operates, the analogy helps us to gain a clearer picture of how life works. The tornado in a junkyard has nothing that matches up with a basic description of the theory of evolution and, thus, it doesnít give us an analogy at all.

    Consider how the two pictures differ from one another.

    The swirling wind of a tornado wonít pick up parts and orient them in a way that allows them to connect to each other. But in a cell strands of DNA or RNA will bring molecular parts together, orient them properly, and attach them to one another. The electric forces acting among the molecules, what chemists know as van der Waals forces, attract certain molecules to the strands, rotate them to align them with the nearest strand, and pull them against the strand in order to minimize the potential energy in the electric field between them.

    The parts in the junkyard donít attach to each other spontaneously. But in a cell, the parts, such as amino acids, get attracted to the RNA/DNA strands and adhere to them. As more parts come up against the strand, they connect to each other until enough have accumulated and so altered the electric field that surrounds them that the force holding them to the RNA/DNA strand diminishes enough for Brownian motion to take them away. We see an analogous phenomenon in a dripping faucet, on which a water blob grows until its weight overcomes surface tension and it falls away from the faucet as a drip.

    Of course, an analogy carries no scientific weight whatsoever. We use analogies only to help us clarify our understanding of phenomena that may be too abstract or complicated for us to conceive easily. We can also use analogies to help us in formulating hypotheses, the educated guesses that we use to guide us in scientific research. But in transforming hypotheses into theories the Scientific Method necessitates that we abandon analogies altogether and rely on physical evidence. Only by comparing our hypotheses with actual Reality can we assure ourselves that they give us a proper description of that Reality. An hypothesis only becomes a theory after it has been proven and verified.

    Analogies are also useful for presenting theories to people who do not want to develop a deep understanding of those theories, who do not want to invest the time and effort such deep understanding requires of us. We must employ good analogies to serve those people well, to give them the information that is theirs by right. Bad analogies eventually get exposed as such and bring their purveyors into disrepute. The tornado in a junkyard is a bad analogy for the theory of evolution and it has been around our society long enough that the Creationists ought to know better than to keep presenting it as a criticism of evolution. And thatís all I need to say.

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