The god of screwdrivers
The Right are fond of simple and simplistic explanations for complex events and social and environmental conditions. Whether it is pretending that sun spots cause global warming, or thinking that a gun in every house is an answer to crime, or that you can go to war against drugs and terrorism, the glib answers come rolling out, losing, it seems, none of their freshness for being endlessly repeated and endlessly rebutted.
And the glib answers are there when it comes to 'intelligent design'. The kind of people who don't want to believe they evolved from primeval slime by way of monkeys (no joke, I'm afraid, much as I try, I don't think anyone, not even St Stephen or St Jon, could satirise the creation beliefs of fundamentalists) have a vision of god as the great mechanic in the sky.
It goes like this. Imagine you have a car. And the car has a radio. The bits of the radio don't do anything by themselves, so the radio must have been installed all in one piece, by a bearded fellow with a screwdriver. And if your neighbor's car doesn't have a radio, but instead has a 10 stack CD player, then this is because that same bearded fellow, still with screwdriver, removed the radio and installed the CD player. And if the engine is driven by a rubber band wrapped around a flagellum, then god must have installed the flagellum.
All of the argument about this bizarre notion has come from evolutionists, including me (eg http://www.huffingtonpost.com/david-horton/irreducible-stupidity_b_21520.html), pointing out that in fact the parts of the 'radio' do have other functions, and evolution works to put them together into new combinations for new functions. But just as with the climate deniers, I think we have greatly over-estimated the knowledge and mental processes of the evolution deniers. In this particular example we have assumed a knowledge of population genetics that they simply don't have.
I promise I will dump the car metaphor soon, but bear with me a little longer. In the real world of cars, away from me pretending that they are driven by a flagellum, there isn't just a difference between radio-bearing and CD-bearing cars. Instead there is an almost infinite variety of size and type and function of radios, and a similar variety of CD players. In addition the cars themselves vary enormously in color, style, engine performance and so on. That is a very busy screwdriver!
Okay, end of car metaphor. Think about animal species, including, of course, us. We all vary, even more than cars do, in every aspect of our being. Not simply the obvious things like hair and eye color and height and fingerprints, but subtle things like brain size and function, metabolic rate, digestive functions, sexuality, strength, allergies, growth, reaction to drugs and religion, and so on. Some of these things may vary geographically in a clear cut way, others vary across the whole species. In many, in fact nearly all, cases, these apparently individual characteristics are not independent but linked to each other in unpredictable ways. Having a higher metabolic rate might arbitrarily let you run faster but result in allergies.
It is this variation, this population genetics, that natural selection works on, without fear or favor, depending on circumstances. Being large or small, having a tail or not, being addicted to alcohol, having dark hair, are neither positive nor negative in themselves, but only in relation to the outside world in which the population finds itself. Conditions at one time and in one place may favor larger individuals, or smaller individuals, depending.
So forget about all the other obvious demonstrations that living species evolved and weren't intelligently designed - the fossils, and the linkages between living species, and vestigial organs, and biogeography - the variability within our own and pretty much every other living species, extant or extinct, demonstrates the failure of creationists to deal with the real world outside the first few verses of Genesis. Perhaps this failure also reflects their refusal to recognise that genetic variation in our own species has more to do with the social and economic questions of the day than any morality derived from later in the Bible or from the economic rationalist's play book.