I'm a bit surprised to see this topic. I would have thought the existence of mimicry was supportive of evolution, so I find it strange that it is used here as an objection.
If there is no mention on talk origins, I would be inclined to guess that is because there is little credible criticism of evolution based on the existence of mimicry.
What is most interesting is his - Nijhout - darwinian explanation of this phenomenon: big initial mutation and subsequent refinement of these mutations.
"Initial step in the evolution of mimicry is likely to have been due to a genetic effect of large magnitude".
Looking at the Nijhout article you cited, I see:
Batesian mimicry is believed to originate by means of an initial mutation that has a sufficiently big effect on the phenotype to give a passable resemblance to a protected model.
This could be a small mutation with a big effect on the phenotype. Don't jump to the conclusion that it had to be a big mutation. I don't see a basis for saying that saltation is involved. On page 589 of the cited article, Nijhout says "So the first step in the evolution of mimicry could involve only a single locus." That would make it a small mutation.
Edited by nwr, : fix typo (inserted closing quote that was missing in last paragraph)