A recent letter-writer in our local paper presented this argument:
Many people believe the evolutionary theory but none practice it. For example, how much is left to chance in the design and assembly of a 747 jet? Nothing is left to chance. Every component is tested to breaking point to find any weakness in design or construction materials. It’s all intelligent design to the highest degree.
I have never seen the design team responsible for my car, but I know it isn’t the result of a chance explosion in a warehouse.
Science is the truth about observable facts. Who would believe that a 747 jet was the result of a whirlwind going through a scrap yard? No normal person would. Yet proponents of evolution say everything in our universe, which is millions of times more complex than a 747, just came about by chance, no design in it.
This argument is something of a creationist straw man. It’s saying that since a 747 could not be produced by a whirlwind in a junkyard, the theory of evolution must be wrong. This would be true only if organisms sprang fully formed from some evolutionary drawing board. But this doesn’t happen – in general evolution proceeds by relatively slow, incremental change. (You might get to life’s equivalent of a 747 eventually, but probably by a more circuitous route than you could ever imagine!)
What’s more – and contrary to popular belief – evolution is not a random process. While mutations and gamete production generate random genetic variation, natural selection acts on that variation in a distinctly non-random manner. An organism with a genetic trait that makes it more likely to survive and reproduce is more likely to leave descendants, & at least some of those descendants will also have that trait. Thus the variation spreads through the population – and it’s not as a result of chance events. (Mind you, it’s important to point out here that natural selection isn’t the only factor in a population’s evolution. Genetic drift may also play a significant role, especially in isolated populations with a relatively small gene pool.)
I’ll get in quick here, because the next claim is often that evolution can’t work because mutations are ‘never beneficial’/’always harmful’. Mutations are never ‘beneficial’? Of course they are! Think of the mutations that give bacteria the ability to resist antibiotics – not good for us, but enormously beneficial to the bacterial populations concerned. What about the extremely rapid evolution of HIV in response to anti-retroviral drugs? (And I’ve given other examples & links here
& – in humans – here