I don't think biology is your strong suit. Losing a sensory organ is a different proposition than creating a new one. Species lose genes/experience mutations all the time, usually with fatal results.

The ID argument is that a "partial eye" is not worth anything, and since it comes at a (metabolic) cost it is counterproductive to survival. Isn't that what the blind salamander proves, that when you have an "organ" that doesn't work, it shouldn't persist? That it won't persist long enough to be a functional one? I'm not sure I would bring this up as an outstanding example of support for evolutionary theory.

Now, I realize that evolution teaches the photosensitive cell conveys some survival advantage, which leads to a recess, which conveys a survival advantage, etc. But that is the evolution of an organ, not the devolution of complexity.

You explain perfectly why the blind salamanders demonstrate evolutionary theory, and then pretend there is some difference between evolving an eye, and losing one that causes problems. But there is no difference in principle.

to argue the reverse. Easy example: I put gas in the car, turn on the engine, and out comes CO2, water, etc. If I put CO2, etc, into the car, it won't make gasoline. True, the chemical reactions will work but you need another mechanism.

You should know I am a theisitic evolutionist--not an ID'er or certainly not a Young Earth creationist. That doesn't matter to the debate. Going from complexity (functioning eye) to non complexity does demonstrate evolution of a sort (not sure if the blind salamander is truly a new species), but the kind that an IDer would embrace--evolution's arrow pointing toward simplicity, not complexity.

What I am really saying (see original post) is this isn't the argument that will make an IDer suddenly sit up and say--oh, now I get it. Just as you cannot seem to think outside of your box and see that someone might think that way, and that evolution toward simplicity is not the stumbling block for non-evolutionist--evolution toward complexity is.

Evolutionary theory makes no predictions about complexity or lack thereof. And loss of eyes demonstrates evolution just as surely as gaining of eyes does. And loss of eyes doesn't necessarily indicate a decrease in genetic complexity--all the original genes may be there, along with a new gene that turns off the original genes.

really have a new species? Or just a mutation, like the host of metabolic diseases that we see in man, like PKU? I used the term "arrow" with some reluctance, because I realize there is no direction according to evolutionary theory, just differential survival. If a primitive organism were to be more fit than a complex one, it would survive (a la the nuclear war roach theory!)

...for animals, whether or not two populations (or individuals) are members of the same species is usually determined by whether or not they can still reproduce successfully. Theoretically, two populations could be separate species with only one gene difference, if that one gene kept them reproductively isolated. On the other hand, there is often a great deal of genetic diversity within species.