based on an essay by William Dembski
-there is a great deal of similarity between cellular and man-made machines, one of which we know to the result of intelligent design
-"a functional system is irreducibly complex if it contains a multipart subsystem (i.e., a set of two or more interrelated parts) that cannot be simplified without destroying the system's basic function." This is subsystem is what he calls the "irreducible core."
-an integrated system has a lot of parts that work closely together to do something
-if one part of the process changes then usually the whole process breaks down or needs multiple changes in order to keep going
-so the core of the system is made up those things that, if removed, destroy the whole function of the system
-irreducible: there isn't a simpler core that can do the same thing
-IC not just about removing parts that shut things down, there can't be another system that does things equally well
-for a three legged stool all the legs are necessary but a tree stump could also provide support for my behind and so we don't have IC
-no other simpler systems can exist, period
-2 step process for figuring out if a thing has an irreducible core
1) an empirical examination to see if we can remove a part, mix the leftovers around, and still have the basic function
2) a logical examination to determine if there is an easier way of doing things
-watching out for cumulative complexity which is when you build on a basic core
-IC core happens only when all the parts are in place
-the problem for natural selection is that it cannot plan ahead - it wants "instant gratification"
-so an irreducibly complex does a function that no other type of system is doing and therefore there is nothing to select from
-could only happen if you rearrange existing parts but there is no evidence that this could happen successfully
-Darwin thought that complex stuff had to come about with "numerous, successive, slight modifications" but how do you build, modify and improve on nothing?
-flagship example is the bacterial flagellum which is the tail that propels a bacterium to its food source
-30 interacting proteins are needed to build and 20 more to help assemble the machine and every one is essential to the task
-yes - the question is how likely is that
-"to attribute irreducible complexity to a direct Darwinian pathway is like attributing Mount Rushmore to wind and erosion. There's a sheer possibility that wind and erosion could sculpt Mount Rushmore but not a realistic one."
-for indirect Darwinian pathways to bring this about there would have to be not only an evolution of existing structures but an evolution of their purposes