Test My Theory: Macro evolution DOES happen?

[Esquilax]

I was discussing a known rapid one-gen "macro" evolution as a possible response to the creationist claim that we NEVER see "macro" changes in species, and the implications for the specimen's chances for successfully passing on that mutation.

You want Hyla Versicolor then, the Gray Tree Frog. It's an American frog that's largely identical to the Cope's Gray Tree Frog, except that the latter is diploid, and the former is tetraploid. Over the course of one or two generations, Hyla Versicolor evolved a double chromosome set that classifies is as an entirely new species. If literally doubling your chromosome count doesn't qualify as a macro change, I don't know what does.

Unless, of course, "macro" changes are supposed to be obvious, outward appearance changes, which only really bespeaks a superficial understanding of biology. If you're being asked for a crocoduck, then you're being asked for evidence of chimera-ism, not evolution. If immense, baseline genetic changes that fundamentally alter the species you're in don't count, then it's possible, just saying, that creationists are just looking for reasons not to be pleased and nothing would satisfy their conditions.