Another point (I’m on my coffee break) needs to be made about “irreducible complexity.”
The arguments about I.R. are interesting, but they ignore certian very big logical flaws.
A typical example normally held up for arguments about I.R. include a discussion of the bacteria flagellum.
The flagellum is an example of a natural motor. It has a stator, an axle, and so forth.
The idea behind I.R. is that if you remove any one component from the flagellum, then the flagellum won’t work at all. Likewise, the flagellum has no extra, non-functional components that can be removed . . . and yet still leave the flagellum functional.
The seems–on the surface–to be a very powerful argument in favor of God’s hand in creation, right?
Not so fast.
This argument makes the tacit assumption that a halfway-built flagellum is useless and does nothing . . . and this assumption isn’t true.
We have all used a tool for something that wasn’t intended. The other day, I needed a hammer in my garage when I was working on a project. I couldn’t find the hammer right away, so I picked up a heavy brick that I was using as a doorstop, and hammered in the nail with this brick.
In a like manner, a halfway-built flagellum is useless and non-functional as a flagellum . . . but is very good for other things, like cleaning metabolic waste products out of a cell.
Yersinia pestis (the microbe that causes bubonic plague) uses a “halfway-built flagellum” to protect itself against certain antibiotics, like pennicillin . . . which is why streptomycin and tetracyclines are the proper meds to treat this kind of infection.
There are other examples in nature. In many animals, urine not only serves to eliminate wastes and toxins from the body, but also as a “no trespassing sign” for other members of the same species . . . so urine is often a means of communication . . . which is one of the many reasons why dogs sniff around to find the exact spot to pee on.
And so forth.
The discussion of the flagellum is important, because it’s one of the examples that is often held up in court when Creationists sue over what is being taught in schools.