I really should probably think this out clearer, but I've had an idea a few days now that keeps leaving and coming back. So I'm going to throw the idea out here and if it's too incoherent, I hope either someone gets where I'm going or I come back and see my mistake. At worst, it gets down-voted and I'm risking karma unless I delete it.

Okay, so the other day I was discussing with a Christian friend who "agrees with micro-evolution but not macro-evolution." I'm assuming other people have heard this idea before. And I started to think about the idea of that comment, and the overarching general view of evolution, and the main differences between macro- and micro-evolution. How could one accept the idea that genes change slowly over time, thus creating slightly different organisms than their predecessors, but different species couldn't develop because of this? My thinking led me to this theory: Could it be possible that someone making this comment is making the error of the Mind Projection Fallacy? Rather than assuming species is a category in which we separate different organisms, words like "fish" and "bear" we use so we don't have to label everything by their exact genes, could they be assuming species is a part of the world itself, the same way genes are, and thus couldn't be changed?

If anyone thinks this is a possible idea, would you have an idea how to point this out to the commenter? If you don't think this is a good theory, would you explain why?